Search This Blog

Tuesday, 20 December 2011

Draught proofing old (but potentially useful) chimneys

Many people have old chimneys that are not used any more. Central heating has done for the chimney what indoor bathrooms did for frozen bare bums. Our chimneys, though might just prove to be a useful and low carbon feature of housing in these austere times. The opportunity to burn wood as a source of secondary heating is just the ticket on those days where you just need a little bit of extra heat in the house to make it comfortable, or when you just need to heat one or two rooms.

The removal of a chimney and / or blocking it off completely therefore seems a bit rash (if it can be avoided). So how can we keep a chimney preserved for the future?

Well it still needs to be draught proofed, but more importantly it also needs to be covered to stop water ingress, the ubiquitous gulls from nesting on it and insects from living in it. So where many people turn to Chimney Balloons as an easy way of reducing the draughts associated with a chimney, we feel that this is the wrong approach. We recommend that you work your way down the chimney because if you start from the bottom it allows the top to get wet, nested on etc and this can cause more problems than it solves.

So for un-used chimneys why not fit a removable Chimney Cap. Eco Home sells the C-Cap (but there are others). This reduces the airflow dramatically, it also has an insect screen to stop little bugs from getting in and of course stops water from entering the chimney. It just clips over and so can be removed, if needed, at a later date. This means that you get to keep your chimney (just in case you want to re-use it in the future when fuel bills get too steep), but that you stop potential damage to it. Once the cap has been fitted then additional draught proofing can be undertaken lower down.

So start from the top and work downwards. If you do start from the bottom then you risk having a really damp chimney stack and this can let damp in that can appear anywhere down the flue line.

Letter box draughts

It does seem a bit strange that we fit lovely new well insulated doors and then put a draughty hole in them to collect (what is becoming more and more) a source of recycling stuff. Well apart from Christmas time I suppose when we tend to get more actual post than junk.

In foreign climes they have got around this by having a separate post box attached to the wall, thus saving on the post getting chewed by the pet and also from having a cold breeze blowing through the house in the winter. In Wales we are not there yet due to the mostly mild climate that we 'enjoy'. We are prepared to put up with worn brushes in our letter boxes, or just plain draughty ones that flap around in anything much past a breeze.

So does it need to be this way?

Well the lovely people at Ecoflap have developed a robust addition for your existing letter boxes. The Eco Flap is a simple system that actually blows itself shut, so the stronger the wind the more sealed it becomes! It also has a nifty system that allows for large items to be posted still, thus not incapacitating the functionality at all. So your insulated door can now become an insulated and draught proof door even with a letter box in it.

I gather from Eco Flap that they will also be bringing out a new petflap soon, so all you dog and cat owners can have an insulated and draught proof cat / door flap as well. Can't wait to try one myself.

Eco Flaps are available from Eco Home Centre in brown, black or white. For how to fit the Ecoflap check out this movie.

Thursday, 15 December 2011

Would being able to see refurbishments help you?

Eco Home Centre is looking to do some research on the needs behind refurbishment in Wales (and the UK). What we are proposing is a centre where people can come along and see how a range of properties have been refurbished in a sustainable manner (using appropriate low waste, non toxic and energy efficient products). The properties will have cut throughs to show how the work has been done and explanations on the key areas like window reveals.

Ideally we would like to refurbish a number of different types of property so that you will be able to find one that is similar to your own home. A guide would then be available to show you around to give you advice and guidance on the work and to offer a greater level of knowledge for your particular situation.

The 'show homes' would also be set up with sensors etc to record the performance of the building so that we can offer real life energy and water saving figures rather than generic ones (that are often over inflated).

So I would like some comments back from you as to whether this type of resource would be useful to you (and obviously it would be) and whether (more importantly) you would visit it (likely to be in South East Wales) and use it to its full potential. Please can you send me comments / suggestions etc so that I can bear these in mind when doing the research. Your comments will be most welcome.

Saturday, 10 December 2011

Bathroom art

We are researching some ideas on creating added value from waste that emanates from the refurbishment work associated with the Welsh Housing Quality Standard. Basically this is work that all the Social Landlords need to undertake to 'improve' the stock in Wales. This mostly translates to fitting new kitchens, bathrooms and boilers. So what to do with the old baths, sinks, kitchen units etc.

So what to do with an old bath?

Metal baths can be re-enamelled and then re-used - they are effectively as good as new.
Plastic baths can be repaired if necessary and re-used

However some are just not viable. Some are just the wrong colour and so the market is just not there, others are damaged beyond repair due to major cracks, chips etc. So what to do? Well an award winning idea is shown below.

Friday, 2 December 2011

Can visible mould and damp be good in a house?

Perhaps an odd question to ask, for how can visible mould and damp be healthy, beneficial or aesthetically pleasing?

The short answer is that it cannot, but there is a BUT. This BUT is quite a big one as well. Being able to see mould and damp at least tells you that there is a problem. Many houses these days are 'tarted up' to sell to un-supposing buyers who take out minimal structural or condition surveys. The main way of making a damp house look OK is to 'dry-line' it. This effectively places a piece of plasterboard between you and the damp wall. Lovely.

Knowing that you have damp, and where it is, can take you on a voyage of discovery, especially with older solid walled houses. You will discover how these houses were made and with what materials, it can also tell you how they were designed to work and how they coped with mould and damp in their long history. After all people of 100 years ago didn't want mould and damp either, so why has your house got it now?

Damp can have several causes and this article will help you to identify where it might be coming from, how to deal with it permanently and which materials to use so that you work with your home rather than against it.

To understand how these concepts and practices work, we first need to understand how these old solid walled houses worked originally. In North Wales, like many other parts of the country, people had to make buildings out of the local materials, so this meant a great deal of stone and slate was used to create walls and roofs. To bind it all together they used lime putty and a local aggregate (stone waste from quarries, sub-soil etc) The walls were either then left bare, or painted with a limewash (basically a watered down lime putty). The insides were rendered and plastered using a lime render (made from lime putty, local aggregates and some binder - sometimes horse hair, wool etc.) These materials were put together as a solid wall with dressed stone to the inside and out and any old rubble through in the middle as packing. These materials work together really well and they allow moisture to pass through them (either as a vapour or a liquid). The inside of the building was drier than than outside as the basic building physics meant that the water was attracted to the outer parts of the wall (issues to do with surface area of the wall, internal and external air pressure, internal temperatures etc.)

So these old houses basically kept the insides dry by allowing the water to move through them naturally. Yes they got wet when it rained, but the building physics and the thickness of the walls allowed this to happen in such a way that the building coped with it.

So what has gone wrong?

Time, does not stand still, and over the last few decades these old houses have been 'improved' using modern materials and techniques to accommodate new lifestyles. We now have central heating, better airtightness, inside toilets and bathrooms, double glazing, cookers and hobs rather than fires and chimneys and quite often concrete floors and wall renders. We have also been tempted into creating a modern feel to the house by using new smooth gypsum plasters and cheap oil derived paints and finishes.

These features have fundamentally changed the way that old buildings are used and this in turn has changed the pressure points on them. The materials that we now commonly use are also placing a new and largely unknown pressure on the house. The effect has been to radically change the way that they function as physical structures and this in turn has led to the mould and damp that we now commonly associate with old properties.

The new bathrooms and kitchens generate a huge amount of water vapour in the internal atmosphere. The removal of chimneys and the replacement doors and windows have radically reduced draughts (this is a good thing of course), but most importantly the use of cement renders, non breathing roof and wall insulation and the introduction of solid concrete floors has sealed the dampness in the house and especially the walls.

Where once water vapour and moisture passed through the structure, now it gets trapped behind impervious render. Where once air wicked away moisture from under the house, via air-vents under the floor, any rising damp is forced by the damp proof membranes into the walls (inc. internal walls). To make matters worse, the cement renders applied to the external walls, tend to crack over time as they don't flex like an old lime render. This lets water in behind the render and then stops it from getting out again. Where does it go? I think that you know the answer now.

To compound the problem, wet walls conduct heat better and this causes cold spots to form and this in turn is the breeding ground for mould. Cool and moist - lovely if you a mould spore!

So mould and damp can tell us that there is a problem and also show us where it is. This then allows us to do something about it. It could be: clearing out blocked guttering and drains; cracked render; rising damp from the floor; failed seals around doors and windows .... BUT at least you can then do something positive about it. If you don't know that there is a problem and it goes untreated it can cause structural failure in a house. Not what you want.

The best remedies are the old ones. By working with the house and using breathable materials (lime putty renders, wood fibre insulation, clay plasters, natural paints etc.) you can reinstate the way that it once worked and let the house do the hard work of keeping itself dry. If you are looking to buy a house just bear these things in mind - look out for: 'blown render' on the outside walls (it sounds hollow when you tap it); dry lined walls (again they sound hollow when tapped); worthless 20 year damp proof injection guarantees; flaky paint and rotting skirting. If in doubt buy a cheap damp meter and take along with you (note that dry lined properties will not appear damp to you or the meter, so a tap is essential).

If the house is fundamentally solid, but damp and mouldy, at least you will be going in with your eyes open and ready for the remedial work ahead.

Tuesday, 29 November 2011

Getting a smooth finish on a lime plaster

Some people are looking for a gypsum style finish on their lime plastered walls. The temptation for some (especially builders) is just to plaster gypsum onto the lime plaster. This is not a pretty relationship between the two and even LaFarge (main supplier of gypsum based products) state that it should not be used over lime plaster / render. So if you are looking for a silky smooth finish what can you do?

It can be achieved in a couple of ways.

1. When the lime plaster is still slightly pliable push in a top coat of lime putty. This is incredibly fine and will be a really smooth finish. If the plaster has dried out too much then you can still apply it, but you will need to give the surface a once over with limewash first and apply the putty whilst the limewash is still slightly damp.

2. Use a clay plaster. This again is a very fine plaster. You will need to slow its drying down a bit as the lime plaster underneath will suck out the moisture really quickly. Using a primer to do this is the best solution. Clay Works in Cornwall have a lot of advice and information on clay plasters. Eco Home Centre will also be running a clay plaster course in the New Year, so look out for that.

These finishes are really fine and also give excellent breathability to the room. If the surface is rubbed against then the main complaint is that you can get dusting from the clay or lime. However this is easily cured either with painting (use a natural breathable paint like a clay paint) or by glazing (a breathable glaze is available from earthBorn - Wall Glaze)

Saturday, 26 November 2011

Guttering - getting it square to a fascia board

Getting guttering square to the fascia can be a problem. If the fascia is not perfectly vertical (and many on older buildings aren't) then when fixed gutter brackets are attached they either need to be packed to make them square or, more commonly, they are left at odd angles either sloping into or away from the wall.

This can cause problems in heavy rain showers. If there is any slight blockage the gutters don't work as they should and can easily overflow either against the wall or over the outer edge and then to who knows where. This can be a major cause of damp in a house.

Packing the bracket will probably work in the short run, but if the packing falls out this can cause even more problems. So, a sustainable solution.

We deal with Lindab guttering and they offer an Adjustable Snap-on Bracket (Code SSK). These are very similar the normal fascia brackets, but rather than being solid metal they have an adjustable metal arm that clots into a grooved receptor and this gives a wide variety of choice to get the guttering square to the fascia. So effectively they twist the guttering into shape to give the best result in ensuring that the gutters run true.

So if you are concerned with the angles of your fascia it is worth stipulating adjustable brackets rather than then fixed ones. If you think that you might have some issues with the fascia then I would go with a 50:50 mix between the two. Cost wise they are similar (adjustable slightly more expensive), but it could save you a lot of headaches and hassle when fitting and living with a new system on an old building.

I have also been informed of the following that might be of import to your particular project -

In order to use the standard fascia bracket (KFK) you really need to be able to snap the guttering in at the back. If the existing roof overhangs the fascia this may be impossible. When you are on a ladder it is difficult to get the gutter to snap in at the front due to the strong rolled edge. In this situation, even if your fascia is vertical, you need the adjustable fascia bracket (SSK) because the guttering can be placed into it underneath the existing roof and the bracket has a snap-on front clip. Not all of the suppliers stock both kinds, and the Lindab literature does not seem to explain the problem!

Wednesday, 23 November 2011

Insulating flat roofs

Many people have flat roof extensions. Seems that they were all the rage some time ago. We were obviously hardier then as well given that most are poorly insulated, draughty and can be cold and quite miserable places. This is commonly re-enforced by the fact that they were often designed to be bathrooms.

Bathing in a room that is exposed on two or three sides with a cold roof is not particularly pleasant in the winter unless one has a suitable radiator on full and the extractor fan on a humidity control.

These flat roof extensions are therefore having to do a lot, especially with regards to moisture. Cold walls, windows and roofs with high levels of humidity just leads to one thing. Condensation and mould.

Most of the heat in the room will be lost through the roof (assuming that it has minimal insulation). So the most obvious job is to get the roof well insulated.

When looking at this the most obvious solution seems to be to install the insulation to the underside of the ceiling. However this can lead to problems. If you have insulation below the ceiling then any warm and very moist air that manages to get above this will condense on the even colder underside of the felt / top covering of the roof. This will then condense and fall back on top of the insulation. This can cause a lot of problems with electrics, damp, rot etc. So this solution is not recommended.

So unfortunately the roof has to be taken apart somehow to either install the insulation just below the main roof covering, or above it. Putting the insulation on top seems to be a easy option, but there is the issue of air circulation, so just plonking some rigid waterproof insulation on top doesn't work as there is an air flow through the existing roof structure that needs to be altered as well otherwise the external cold air will just flow under your lovely new insulation and effectively make it useless.

So the only real way of tackling this is to look at seriously upgrading the roof when replacing the roof covering. This allows you to change around the air circulation so that there is no external air source into the structure. This then allows you to insulate next to the underside of the roof covering. Airtight and water tight membranes are important here though. Your roof covering does not breathe and so you must stop any warm moist air from reaching it. By using membranes and also by adhering the insulation to the roof covering you effectively create a warm surface in the room, thus stopping condensation from forming on it.

All in all, it might be worth thinking about replacing the flat roof with a well insulated sloping roof!

To make all of this clearer follow this link to Brian Murphy's excellent GreenSpec website - he has pictures that speak a lot of words!

Tuesday, 22 November 2011

Mouldy window reveals

On my house I have a problem with mould in the window reveals. This is because it is a cold spot in the construction of the house. The walls here are effectively thinner than the rest as the window only sits back a few inches from the outside of the house. With my windows also not being the best it is a perfect haven for condensation and hence mould. Cool and wet is not the best combination in a room.

So what to do about it?

Well basically it just needs some additional insulation to keep it warmer. By doing this it will stop the water in the air from condensing on the walls and hence stop the perfect conditions for mould.

There are a few products that can help here. I will avoid using the phenolic backed plaster boards as I have developed a loathing for them. They are a legacy waste (what do you do with them at the end of their life?) and also can trap moisture behind if not installed perfectly.

Given that your walls will no doubt already have paint on I think that the easiest solution is to use InsOwall insulating plaster. It is very sticky and so you can prep the walls easily just by scratching back some areas to the plaster and then just with some wood to give an edge you can easily apply the plaster (up to 40mm thick) into the reveals. This can then be plastered over to give a really good finish with lime plaster, clay plaster or gypsum (if you must). It is possible to get a final finish with the InsOwall, but in reveals this can be a little tricky to the DIYer.

Other options would be:

Hemp / Lime plaster for those homes where good breathability is essential (InsOwall is a semi-breathable material)
Calsitherm, again where good breathability is required, but also some additional thickness and strength

You could also use Aerogel, but it is expensive and getting it in small enough quantities would be an issue.

Saturday, 19 November 2011

How to dry out damp solid walls

The solid walls so common in Wales are prone to damp after the 'modernisation' they have received over the past hundred years. The addition of external cement renders especially has locked moisture into the walls and the remedial work of injecting damp proof courses just doesn't work. I have covered this point on numerous occasions in previous posts. I might be getting obsessed!

So the scenario posed here is having an issue with rising damp with an external cement render. So how to cure this problem in a quick and relatively easy way?

The best thing is to remove the offending cement render to allow the wall to breathe. In order to achieve this at lower levels (assuming that the upper levels of render are sound - no hairline cracks etc) you can cut a straight line in the render using an angle grinder. The lower render can then be knocked off using a hammer and bolster - it may well come off relatively easily as it has probably 'blown' away from the wall. Unfortunately this process may well take off the glazed surface of the bricks. So in order to create a finished surface we would recommend applying three or four coats of lime wash.

Limewash is really breathable / porous. This has two advantages for us:

1. It will help to suck out the moisture from the walls on drying days (these are effectively any day where is it dry, windy or with light rain)
2. On heavy rainfall days it will help to keep the wall dry. Basically the limewash gets saturated with the rain and then it sheds the excess rainwater off of the surface

This gradient of porosity / breathability is the key to a successful wall. The inner finish should be between 3 and 6 times less porous than the external finish. The internal pressure and breathability gradients then encourage any moisture in the walls to the external surface where they can be dried by the weather.

Ultimately if you want a render finish again on the external wall, then look to render it with a lime putty stone dust render topped off with the limewash again. Note that the limewash and putty should be 'hard' lime putty that comes from limestone rather than the 'soft' putty from chalk.

Thursday, 17 November 2011

Gypsum plaster and lime render

One of the major mistakes that we see in refurbishment of old solid walled houses is the use of modern materials over over the original substrates. I have written before about the use of cement render over these types of walls and what damage this can cause in terms of damp and potential structural failure. However, we now need to look at the inside walls.
Gypsum plasters are too hard and brittle to flex and move with the building, and most of them will break down in the presence of moisture. Lime of course allows moisture to pass through it and hence can allow moisture into the gypsum (in the case of rising damp or rainwater ingress.) When gypsum has lost its structure it cannot regain it and so it will then become hygroscopic and just attract more moisture to it. If then happens then it has to be removed.

Some gypsum has water repellents added to it, but this then just seals the surface of a wall and prevents it from 'breathing'.

So either way the gypsum and the lime just don't work together. So really if you are working on the internal walls of your home it is best to steer away from combining the two as there is a lot of room for conflict. So when replastering the walls we would recommend using lime plaster.

If you want a really smooth finish you can still get this by using a clay plaster skim coat or by pressing in pure lime putty into the plaster / render when it is still slightly pliable. Remember though that you will need a breathable paint finish to maintain the original functionality of the wall. We would recommend either a claypaint, a limepaint or a limewash for this.

Wednesday, 16 November 2011

Sound and thermal insulation all in one

Eco Home Centre recently helped a local home-owner to insulate their home. However the pressure was not for thermal insulation more for acoustic. The house, built in the 1980's, was typically badly built. Little insulation in the external walls and ceiling, but also none in the floors or internal walls. The house therefore reverberated with noise from any corner of the house.

The house was also built in a terrace and the sound leakage between the houses was also noticeable. So we devised a plan of using one product to solve the problem rather than using a conventional thermal insulation and a separate acoustic solution. This product was a wood fibre board. The product was a 40mm deep board and it was finished with a plaster applied directly onto surface (although the belt and braces approach is to use a mesh as well).

This solution has really 'deadened' the sound in the room and also provided a good level of thermal improvement with minimal loss of space in the room.

The sound inbetween the floors was dealt with using a dense sheep's wool insulation. Ideally a hemp wood fibre mix would have been used, but this was in short supply and transport costs took it out of the financial picture.

The sound inbetween rooms was sorted by using the same sheep's wool insulation in the stud walls (75mm in a 100mm gap so as to leave an air gap that gives better acoustic insulation) and then re-boarding using and woodwool board. These boards are less uniform than plasterboards and also heavier and thicker, hence they give better acoustic properties.

So with all these simple improvements the choice of materials had a number of benefits:
  • It was cheaper than using specialist thermal and acoustic insulations
  • It was thinner than using stud work on the walls
  • It was healthier as the woodfibre boards help to temper chances in humidity levels
  • The products are recyclable
  • The products had a lower carbon footprint
  • The products are natural and contained no harmful materials
All in all the house is now warmer and more pleasant to live in. Also the work was done by a general builder with a little instruction from the Eco Home Centre. Eco Home Centre also sourced all of the 'non-standard' materials and products for the project.

Tuesday, 15 November 2011

Eco Paint Chooser

This is a post with a question. Would you like to see an Eco Paint Chooser? We are looking to develop a tool for the website so that we can guide people towards the right paint for their particular situation.

Basically all natural paints are a sum of their parts and so behave differently from conventional paints (that are designed to all work in the same way - so as not to confuse builders and decorators). People also live differently and rooms in homes have different functions and hence demands upon them. So there is a supply and demand equation here that needs to have some guidance for the users / choosers.

Would you like us to develop this as a function on the Eco Home website? If so please let me know and I will put something together. Many thanks, Peter

Friday, 11 November 2011

Mould in difficult places

Sorting out mould and damp is a bit of a nightmare in older homes. I have dealt with the causes of damp and hence mould in other posts on this blog, but in many situations it is difficult corners and walls that need attention, but the costs of actually solving the issue with beyond current budgets.

The first thing to know is where the damp and mould are coming from. Having a longer term plan of how to deal with the issue with important so that you don't double up on work. If the render on the outside of the house is making the wall damp and cold for example the best solution is to deal with this externally. So doing a lot of internal work may not be necessary. So are there some 'holding measures' that you can do that are simple and relatively cheap that are also eco-friendly?

One 'solution' is to use a mould treatment. Auro do a step by step system that kills the mould, then a spray of paint that stops the mould from returning. It does this using hydrogen peroxide and then a lime based paint. The additional alkalinity of the paint inhibits the mould from returning.

Another possibility is to keep the wall surface a little bit warmer. An insulating paint will do this and may well be able to keep the surface warm enough to stop the mould from finding it attractive. You will though have to kill the mould first as otherwise the vast amount of latent spores will give the mould a fighting chance. Thermakote have an additive that can be added to any paint to achieve this.

Ventilation might also a root cause. Just by creating an airspace around the mouldy area might be enough to reduce its attractiveness, but again you will need to kill the mould first. Moving sofas etc away from walls can facilitate this air flow. People also fear losing heat and higher bills by having extractors on. However by not having them on in key rooms like kitchens and bathrooms can really give mould the conditions it needs to grow. Think about it like this. When having a bath or shower, or when you are cooking, you are introducing a lot of heat into the room, so by having an extractor on you are effectively just removing this excessive heat as well as the excessive moisture. Trying to keep hold of the heat as well as getting clean or a meal is just being a little too greedy!

Not introducing any more moisture into the house is also key. So drying clothes on radiators is another major cause of mould at this time of the year. A difficult one I know as it has been known to rain in Wales during the Autumn and Winter, but it is worth planning washing around the weather if you can.

If you are feeling a little more DIY-ey then there is not a great deal of cost involved in solving some of the fundamental problems associated with damp. Removing render up to a metre outside can just be the case of using / hiring / borrowing a disk cutter (to make a nice straight horizontal line in the render), a hammer and bolster (to knock off the cement render) and then some limewash (really cheap breathable external paint) to cover up the exposed brick and stone. This will allow excess moisture to escape the walls to the outside and hence dry up the internal walls. Mould does not like dry walls!!

If you need a little bit of proper insulation but don't have the space to put in stud work etc (keep away from dry lining please!) then think about the InsOwall insulating plaster. It can go over existing plaster and so you can add 10, 20, 30 or even 40mm of insulation that will better the thermal performance of the wall by a minimum of 35%. Again having a properly insulated wall will stop the mould from returning.

For individual mould and damp advice please give the centre a call, or book for an Eco Home Report.

Thursday, 10 November 2011

Can I stop external wood from greying?

Wood will naturally change colour as it ages. Some people like the fact that woods like oak and cedar grow grey with age, a reflection of us as humans I suppose. Others though like the elixir of youth and want to maintain the colour, depth and vibrancy of wood in its prime. So how can we do this?

Well, if the wood (patio / cladding etc) has started to grey, you can get it back to looking great by using Oxalic Acid. Osmo's Wood Reviver is the product that we stock to do this job. A good covering and a scrub will bring the wood back to its original colour. Once the colour has been retrieved, work can start to preserve it.

The wood basically needs some sunscreen to reduce the effect of UV rays. Most preservers have a colour in them and this acts as a good UV protector, however clear oils and preservers commonly do not provide any UV protection. So the best advice is to use a coloured wood oil and to ensure that this is topped up annually to give ongoing protection. However if you wanted to use a clear oil then you can get some UV protection from products like Osmo's 410 and 420 Clear UV Protection Oil. These give a factor 12 level of protection (effectively reducing the greying effect by a factor of 12).

Wednesday, 9 November 2011

Bongaboard and the Eco Home Centre

Now this is a tad strange. Bongaboard - a balance board - and the Eco Home Centre? Well Andrew from Bongaboard is an entrepreneur in Cardiff who has just started making personalised balance boards for the skating and surfing market. Being a conscientious chap he wanted to use eco-friendly products in his designs and boards, so after a few weeks of to-ing and fro-ing  we came across a formula of products that work brilliantly on the boards.

Andrew has used Auro Wood stain and earthBorn varnish to make these boards and they look great. So if you are looking for a present for Christmas / Birthdays for balancing boys and girls you would be hard pressed to find a better one than a Bongaboard. You can have any design you like, or just get one of Andrew's funky ones.

So it is lovely to see quality eco-products making it into the manufacturing process. Bongaboard website is

Friday, 4 November 2011

Insulation and airtightness

These are two peas in a pod. We had a presentation last year from ProClima about airtightness and its importance and some of the figures were terrifying. The effect that a lack of airtightness has on insulation values is dramatic. When one thinks about it, the correlation is obvious. If cold air is being driven through, or around, the insulation by draughts then it becomes irrelevant. Good airtightness is therefore important for preserving insulation properties as well as managing ventilation effectively.

We have no real appreciation for airtightness in the UK. Our mild and breezy climates has meant that we have learned to live with draughty homes and we sort of accept it. But in these days were energy efficiency is more and more important we really do need to start to get to grips with airtightness and all the various materials that come with it.

We use insulation in a strange way in the UK. Builders rarely follow instructions from manufacturers on how to fit their products as normally this involves some attention to detail with its associated costs and time. So we often see new buildings going up with phenolic boards in cavities, but are the boards taped together? Rarely.

Membranes are also a whole new building material that is not widely understood. Membranes are used commonly on roofs and timber framed buildings, but until recently they were commonly just stapled to the wood and left. No tape in sight and also no thought for how to join it to elements like brick, block and stone. So again little point in membranes if they are not fitted correctly.

Longevity of seal is also overlooked. With many projects the airtight membrane is an integral and hidden element to the building, so it is very unlikely ever to be checked after the build is complete. Many sealants are not very long lasting (especially in certain harsher areas of the house like on the roof - extremes of heat, or in a floor - exposure to damp) and so when they fail after a few years, all the good work of sealing it up may be wasted. A good quality seal and tape is therefore essential to ensure that the property retains its airtightness into the future.

So be careful when having work done. Insist on using airtight tapes and sealants where required, otherwise the warm home that you were hoping for may not fully appear, especially on the cold windy days that we occasionally have in a Welsh winter.

NOTE. I have just been to a large supplier of insulation and membranes to pick up some stock for a customer. They had the membrane that I needed (a breather one for underfloor insulation), but NO tapes or sealants to go with it!! Apparently there is no demand for the tapes etc so they don't keep them in stock. See how the conventional builder works?!

On the back of that I have now got some ORCON F sealant and TESCON No.1 tape in from ProClima.

Wednesday, 2 November 2011

Multi-foil insulation - does it work?

The construction industry is seen as being very conservative on the whole. Trying to get new materials to be used is seen as a difficult and costly exercise. We have stuck with brick and block for many years on individual builds and extensions, but there are a few exceptions. Multi-foil insulation being one of them.

Loft conversions have fuelled the demand for multi-foil with its attractive looking headlines of 200mm worth of insulation in 20mm. Headroom issues can rapidly disappear when these figures are being bandied around. Also it is seen as a clean and quick way of insulating. No fibres to worry about and a few staples later the roof is done! Not only that, some come with BBA certificates to prove that they work.

I like to think that I am not too sad when it comes to looking at product data, but I did feel compelled to have a closer look at the multi-foils, because if they did work, it would be a great relief (given all the roofs that they are 'insulating') and also something to promote. This is what I found:

The BBA certificate for a leading brand was tested under the following conditions:

Roof make-up was:
Batten (non vented void)
Batten (non vented void)
50mm phenolic board insulation

With these factors and additional insulation in place it worked. Hooray!


1. You need another insulation in place - they do not pass the test on their own
2. You need to tape all the foils together to help form the airtight (non vented) layer
3. You need to create a permanent airtight seal against the wall / structure to ensure that the non-vented layer stays unvented

Only three BUTs, however they are pretty major ones. I don't know of any jobbing builder who would really know about the need for the additional insulation or the reliance on airtightness. So if the insulation is not fitted correctly, diligently and ultimately checked for airtightness then what? Well I think that we can safely say that virtually all homes insulated with multi-foils are not performing as specified and consequently we have created another potentially great product (except that it doesn't deal with decrement issues) that has been mis-used, potentially mis-sold and has led us to higher energy use than would have normally been expected.

So if you are thinking about using the multi-foils for a loft conversion you will have to insist on:

All foils being taped together using a very long lasting tape
50mm of additional insulation being added
All joints with the wall, roof etc being sealed with a very long lasting airtight sealer / tape

Good luck!

Friday, 28 October 2011

What is a sustainable kitchen?

Kitchens are one of the focal points of any home. This allows people to 'show-off' their eco credentials during dinner parties and such-like. Oh, how Guardian reader-ish. But seriously, having a well designed kitchen that will last a long time and also use sustainable materials is a real bonus for any home. People often pay really big money for kitchens that look good, but actually are not very good quality and do not last as long as would normally be expected.

Kitchens also suffer from trends and fashion. I think that we have all heard of people moving in to new homes and immediately changing the kitchen over. This is of course a huge waste of resources, unless you can re-use or recycle the kitchen.

Colour and style are important where you are going to spend a lot of time, but this can easily be changed by painting doors, just replacing the doors, changing over handles etc. There is generally no need to rip everything out, skip it and re-new.

However, there are times when needs must and a new kitchen is required. So what are the options?

The following are points that could be thought about and that might alter ones choice:

Look for really good carcassing. This is the backbone of a kitchen unit and is often overlooked. Many companies offer lovely looking kitchens (basically good quality doors) at reasonable prices. This is often achieved by having poor quality carcassing. Think about it. The hinges rely on a firm base (carcass) and so if this is not strong enough the wear and tear will soon become evident. How many kitchens have you seen with poor fitting doors and drawers after a couple of years? We would recommend either using plywood or min 18mm particle board. It is also possible to use recycled plastics for carcassing. This is great if you are in a flood area,or prone to leaving taps on, having a dodgy washing machine etc.

Raising the carcassing off of the ground is also a little tip. Any particle board that gets wet, will expand and effectively ruin the units.

Specify recycled content doors and drawers. Milestone up in Yorkshire have a range of kitchens that have very high recycled content. (

Specify A or A+ rated white goods

Look at housing noisy machines (washing machines etc) elsewhere so that they don't drown out conversation when on

Make sure any punctures through the wall (outflow pipes for sinks, washing machines etc.) are sealed up properly to reduce draughts.

Dish washers are regarded as being more water efficient than washing up, but they do use electric for heating and so are less efficient (bearing in mind overall efficiency of the electricity grid) than options like gas heating, so weigh up what suits best - water efficiency or energy efficiency. Personally I would go with energy, but it does depend a bit on where the boiler is, dead legs, boiler efficiency etc.

Work tops can be made from a variety of materials: recycled plastic, recycled glass, wood chip, solid wood, marble, granite etc. I think that locally grown timber or recycled glass are the best options. The plastic is often not heat proof and the stone options are imported from afar (Italy and China being a couple of the main exporters).

Think about using a good quality heat exchange system for above the cooker (hood) or just for the room generally. Kitchens do produce a lot of heat and this could be usefully transferred to other parts of the house.

Floors are best to be made of an easily cleanable material. Wood and tiles are good options here.

Maximise the natural light in a kitchen. It is a place where we spend a lot of time and having it swathed in light makes for a better internal environment.

Use scrubable natural paints as a finish. Green paints are a good option here. However in areas where splashing is likely we would recommend tiling these areas (around sinks, cookers, hobs etc.)

Provide enough space for recycling. Kitchens generate most waste, so having space for your food, green, plastic, metal (or mixed) and general waste bins is very useful to have here. You might not need to have the bins here, just smaller collection points so that you can take it out daily to the main bins.

Fit LED lights. In kitchens we generally need good quality and instant light. This can only be achieved in an energy efficient manner with LED bulbs.

Remember the Golden Triangle - the linking of the fridge, cooker / hob and sink in a close triangle so that you can access them all easily and quickly when cooking.

Fit extractors to the lee side of the house where possible to allow them to work properly and efficiently. See post on extractor fans.

Happy cooking!

Friday, 21 October 2011

Easy to clean natural paint

Natural paints are products of their ingredients. They are all different and have a range of characteristics that distinguish them from each other. This is completely different from conventional modern paints which are designed to work in a similar way to each other.

So some natural paints work well with lime plasters, others have no VOCs, some use linseed oil, some soya oil and others no oils at all. This alters how long they take to dry, how well they cover, what type of finish they create etc.

One thing that natural paints have had problems doing in creating a scrub-able surface. Most people don't scrub their walls down, but for those with particularly artistic young children, or very happy dogs who like going for walks in the park in the rain etc it might be a necessary task.

EarthBorn produce a wall glaze that will sit over the top of their clay and emulsion paints that will produce a wipe-able surface, so this is one option. However Auro have created a scrub-able satin paint, the 324 range. This is a very 'green' product that is made from high quality raw materials that are all responsibly sourced. So this is another option, but it is an expensive one. The third option is the Green Paints Emulsion range. This has just been reformulated to be a scrub-able paint. It has a soya oil base that has been responsibly sourced, but cannot be guaranteed GM free. However it is the price of a normal natural paint, so it may well be the answer for people needing to clean their walls, whilst maintaining their sustainable credentials.

Plastering partially renovated walls

I have just been renovating one of the rooms in our house. This has meant taking off the wallpaper and stripping it back to the plaster. Aprt from the multitude of other layers of paper and paint that we uncovered, I also managed to unearth a range of different plasters, past repairs and some areas in need of total removal.

The old lime plaster / render on the walls was mostly intact, but of course where a damp proof course had been put in years before this meant that the lower portion of the walls were cement render. This is attached firmly to the walls and even though I would have loved to of removed it, it would have damaged the wall too much for it to the really viable. Of course the water proofed cement had pushed the water up into the old render and focused it here. So in these areas the render had suffered from salt deposition and the old paper and paint had sealed in the moisture for so long that the plaster needed to be removed. So I hacked off the old render and replaced with the lime render (lime putty with stone dust of course!)

Around the reveal on the window I found a complete bodge job. The old story of windows slowly getting smaller as they have been replaced over time. So brick pillars had been built up the edges and the lintel was at least 6 inches (150mm) above the window and this space had been filled in with .... yes, you guessed it, paper (well a couple of old cement bags to be accurate - great to see recycling going on with the builders of old!) No wonder this area was always cold and attracting condensation.

In this area I decided not to use lime render, but to use the InsOwall as it was an external wall and the construction meant that it was basically a single skin wall in the zone immediately next to the window. this would give the area a better insulation value and hence reduce the risk of condensation.

So after a lot of hacking off, rebuilding, re-rendering with lime plaster, InsOwall, as well as the old plaster and the cement render and gypsum lower down I am left with a right old mix of surfaces. Some are breathable, some not so, some inbetween. They also have a different texture and finish. This is a plasterers nightmare.

Plaster will be drawn at different rates dependent on the different substrates. So getting a finish would be almost impossible. So what to do?

I need to maintain a breathable finish over the majority of the walls, so the option I have plumbed for is to use silicate primer. Earthborn and Auro both produce silicate binders / primers. This will then even out the suction between the different substrates and help the plasterer. I will be using lime plaster to give the final finish (but I might also experiment with clay plaster as well on one wall as this will give a smoother finish).

I will let you know how it goes after the plasterer has been in!

Wednesday, 19 October 2011

Damp proofing doesn't work*

A bit of a headline I admit, however, there are a number of very common situations where the recommended damp proofing techniques just don't work. So the * is there for qualification purposes, as some damp proofing works, however it depends on a number of factors - the wall, the damp proofing system and the skills / quality of the installer.

The most common area where conventional damp proofing does not work is when dealing with older rubble filled solid walled houses. Sounds very specific, but actually this encompassed virtually all the pre-1919 houses in Wales and the UK. The common terrace is built from a mix of stone, brick and rubble. The walls are generally stone, with brick used where a clean finish was required (doors, windows, chimneys etc.) with the construction technique being to create two reasonably faced edges for the walls and then infill the middle with any old stuff and some lime mortar.

The stone used was a mix of whatever was available locally. Sometimes this meant the local stone, but in port towns and their environs, it was often ship ballast so this could have come from almost anywhere. These stones have different properties and this complicates the picture, however the main point is that the walls were a right mix of materials all held together by lime mortar.

This construction technique means that the walls are full of cavities, fissures, voids, so pumping a load of waterproofing liquid under pressure into them just means that the fluid travels the easiest route, whether this be up, down, across, whatever. So the treatment is not contained / localised where you want it to be. Consequently the damp proof line that is being attempted just will not be achieved.

Creams suffer the same fate, though to not such a great extent, as at least these stay where they are put, but you could find yourself using a lot of silicon cream and still leaving some gaps for the damp to travel up.

For rubble filled walls there are a number of solutions that will work (as long as they are specified and fitted correctly). These include

1. Electro-Osmosis damp proofing
2. Using the right renders, pointing, paints etc on the exterior walls
3. Correct drainage and heights of external floor finishes

So for individualised advice please contact the Eco Home Centre. Builders, damp proofing companies and building societies are generally wrong on damp and will just use damp proofing that at best only working in part and at worse can cause even more damp and insulation problems.

Friday, 14 October 2011

Extractor fans and prevailing winds

Building regulations mean that we have to install extractor fans in high humidity rooms like bathrooms, kitchens and toilets. This is especially important in non-breathing structures where the walls cannot assist with moisture management.

The extractors are designed to take out warm moist air to help ensure that damp and condensation issues are minimised. There is an issue about size and type of extractors as most are simple on-off that are linked to the light switch. They are also standard sizes that have little to do with the amount of moisture in the room. Bathroom extractors are 100mm fans and kitchen ones are 150mm. If they are anything like the ones in my house they tend to be too small to be really effective when showering or having more than two rings going on the hob.

The effectiveness of the extractors can be increased by using the ones with timers on, or ideally humidity sensors. These then keep the fans on until the humidity levels reach a low enough level. The timed ones at least give a bit more time for the warm moist air to be extracted to the outside.

All of them, though, can be even less effective if they are placed on the walls that face the prevailing winds. Their already weak motors cannot compete with the prevailing wind. For example the ones in my house are on the west and south facing walls and the south westerly winds that occasionally blow in Wales play merry hell with them. When not in use, the external shutters are constantly being blown around by the wind, which can be very annoying at night. Clatter clatter, humph!

So my advice is to think about this when deciding how to manage humidity in these areas of the home. It might be better to vent through the ceiling and out through the eaves rather than drilling through the closest wall. If venting through the eaves, again look at doing this to the East or North if possible. This might affect the power rating required for the fan and its cost, but it is better to have something that actually works rather than not.

This is a simple piece of knowledge and logic that is not always simple to enact, however it is worth bearing in mind if designing a new bathroom, refurbishing an old one etc.

Wednesday, 12 October 2011

Report on in-situ U values for older buildings

In an early post called 'are solid walls really that bad at insulating' I wrote about the fact that some research has been done on U values of solid walled buildings and how they were different from those calculated in BuildDesk (this is one of the main software programmes that are used for calculating U values in the UK and hence forms the basis for calculating amounts of insulation etc). Well I have decided to create a link to the report called the SPAB Report by Dr Caroline Rye. This is a pdf of about 1.2Mb.

Effectively is says that:
1. Nearly 80% of the BuildDesk U value calcs were significantly wrong compared to the in-situ tests (i.e. what happens in real life)
2. The BuildDesk calculations were worse at the older stone walled buildings, but OK with the more modern walls they tested
3. In virtually all cases the Build Besk calculations showed higher U values than were actually measured and hence it underestimates the thermal performance of the wall
4. The thicker the wall the better the thermal performance
5. The need for modern radical insulation measures is often not necessary and could have harmful consequences

So again if you are looking at a Barn Conversion you may wish to use this report and the figures it contains to show your architect / building control. This is a really vital area of work that is so important to get right, otherwise we risk creating no end of problems for our heritage in the future, as well as using un-necessary resources in the meantime. Please share this report as widely as you can.

Saturday, 8 October 2011

Designing a refurbishment

This is a difficult topic to write on as each house is individual - a sum of its parts, its history and of its future. So this will be a set of ideas, hints, observations rather than a definitive guide. For an individualised vision please give us a call to arrange a Home Report (see page on this blog for information).

Layout - should you join rooms, split rooms, change function of rooms? This is really down to a range of factors, including: family size, location, style of house, orientation of building, size of house, lifestyle, etc. Personally I think that we join rooms too readily in the effort to 'create space'. However, knocking through, can lose a type of space. Physically it loses wall space (which might be important), socially it loses separate space (could be important if people want to do different activities - watch TV, listen to music, play instruments etc), environmentally it can mean higher heating bills because of not being able to concentrate heat into a smaller space for those cool days during the year.

Sound - refurbishments give you a chance to acoustically insulate (normally thermally at the same time) rooms from one another. This is an important social element that is often overlooked. Isolating floors from each other helps with sleeping, facilitating different independent activities in the house and also with heating bills as it allows you to only heat the rooms that you want to.

Social gradient in the home - homes should have an inbuilt social map with the most social areas being closest to the main door and the most private areas being the furthest away. This not an element that most people have to worry about as their bedrooms are upstairs and the main door takes you into a hallway with the kitchen and living room off of this. However some homes do have to consider this. Making a home feel right is important and so thinking about social interaction within the family and friends is important. Location also has a large impact on this, as situations next to roads, south facing aspects etc can all complicate the social aspect as noise. light and views might be in the 'wrong' place as far as the layout is concerned.

Draught proofing - this is a chance to get on a favourite hobby horse of draught lobbies (independent porches). If you don't have a porch (by this I mean a proper one that is thermally independent from the rest of the house and also of a reasonable size) think about creating one. The best ones allow you and the family to gather together to welcome and bid farewell to guests without losing all the warm air from the rest of the house. They also have space to coats, boots etc. They can be features in themselves and offer a range of social and practical functions.

Light - maximising natural light is perfect for a sense of well being, lower electrical bills and also creating a sense of space. Increasing window sizes, creating new windows or installing sun pipes etc are all ways of getting more light into the house, however you need to bear in mind heat loss. So look at maximising glazing to the south rather than the north.

Future proofing - think about what might happen in the future: larger family, new technology on the house, different fuels etc. Have a think about what might happen at a later date and possibly build in some features that will save you some money in the longer term. Rewiring might include provision for PV panels, an electric shower, circuits for a future extension. A ground floor extension might be built with foundations appropriate for a two storey structure etc.

Low maintenance - thinking about cleaning and life span of materials comes into play here. Do you fit cheap plastic guttering that will require maintenance / replacement every few years or just fit a steel system that might be more expensive initially put will save you time, effort and money in the long term. If replacing windows think about using inward opening ones on the first floor and above as they can be maintained and cleaned easily from the inside.

En-suites - research has shown that having en-suites is not ideal for family life. It is actually better to have a larger shared bathroom rather than lots of individual ones. It encourages interaction in the house, a sense of sharing and being able to live together rather than encouraging people to live apart. Having a separate toilet though is a good idea as there are those times when you don't want to share!

These are all factors that can have a radical influence on refurbishment plans, so it is worth having a really good think about what you want the house to look like at the end of the whole process (bearing in mind that you might be doing it all in stages). Making a house a home takes more than just getting in the builders!

Friday, 7 October 2011

Eco 'bling' - do we need it?

Many people get carried away with all the new technologies coming out. It seems at times that people start from the add-ons and forget the fundamentals.

A classic example for you. On Flatholm Island (in the Severn Estuary) they have a problem of power supply for the running of their accommodation, visitor centre etc. So in order to get around this they have installed a 6kW wind turbine and around 10kWp PV along with two generators and some solar thermal arrays. Cost a packet as you can imagine, especially having to get it all out to the island and put in the infrastructure. BUT, their main use of electricity is pumping water up from the Victorian rainwater store across the island to the farmhouse. Did they minimise water consumption first through aerating shower heads, low water flushes on the toilets, etc? The answer is, of course, no. On the back of a stamp I estimated that £250 spent on water saving measures would have saved them £30,000 in renewable technology.

So the message is that we really need to start from minimisation of resource use and then look at the eco-bling (if indeed it is even necessary).

By investing in the 'boring' elements like insulation, good design, draughtproofing and airtightness, water minimisation measures, etc you could potentially save money on your overall budget by cutting out the need for the eco 'bling'. You don't need a ground (or air) source heat pump (at around £10-15,000) if you insulate your home so well that it does not need a heating system.

For certain areas of living, we do need energy - electricity and domestic hot water for example, so having some renewable technology is advantageous here, but again it begs a wider question: Is it better to invest £10,000 each on PV systems or to reduce use down to an absolute minimum and ultimately de-carbonise the grid? I recognise that the Feed In Tariff skews all of this to a large extent, but the principles remain. Minimising usage and wastage should always take priority so that we minimise the need for expensive bling.

When thinking about a refurbishment (or new build) really have a close look at where your priorities are. Can one cut out the expensive add-ons and use these savings to really make a lasting difference to the consumption needs of the home? The Feed In Tariff only lasts 25 years, whereas insulation lasts for the lifetime of the house.

Thursday, 6 October 2011

Eco fans

Not you, although one assumes that you are an Eco Fan of sorts!

Eco Fans are little stirling engines that sit atop of ones stove (wood burning, gas etc, as long as it has a flat and level surface) and help circulate the hot air from around the stove into the room. Amazing little things that are driven by heat. So no power to them, they just get to an appropriate temperature and start to waft away.

They are brilliant at getting heat from behind stoves and into the room. The hot air therefore does not travel just upwards to the ceiling it is slowly pushed into the room at a much lower level - ideal if you have an older high ceilinged house.

I have had one in my front room for a couple of years and been very impressed with it, especially since our wood burner is set back into the hearth and so tends to heat up the register plate quite well and hence we lose more of the heat to the chimney and the neighbours.

I know that PowRed in Cowbridge Road has a special offer on at the moment, so where they were once £120, I think that they are about £90 now.

Underlay for carpets

I had a question last week about which underlay is best if you are looking for a sustainable option.

There are a range of underlays available however the ones that I think are the most available and also suitable for a home are:

1. Recycled cotton / felt underlay for deep cushioned areas like living rooms, bedrooms etc. This is the basic non rubberised version that should be available from all carpets outlets.

2. Recycled tyres underlay for heavy wearing applications like hallways, stairwells etc. This has been widely available through many of the main merchants.

Personally I would avoid all rubberised underlays as they will slowly decompose and also give off a range of toxic fumes as they do so. The amount of carpets I have lifted to find dust underneath - terrible stuff.

A word of caution though. You may specify and buy good underlay and some lovely natural carpets, BUT carpet fitters will insist on using glue! This stinks and is just not necessary as long as they fit the edge grippers well enough (and this is not difficult). Please INSIST on no glue. It might make their guarantee a bit more secure, but it also hampers any time that you want to lift the carpet in the future as well as stinking the house out for days.

Clay plastering vs gypsum

Gypsum plastering is the modus operandi of the common plasterer. It is smooth, fine and cheap and colleges train people how to work it and get it looking as flat as you like. What is there not to like?

On the face of it, if you have a modern house and plasterboard finishes and a professional coming in to do the work then it is an acceptable route to go down. However, if you want a breathable finish that has a natural beauty to it and that is as easy to work as gypsum, but a lot more accommodating for an amateur then clay plaster could well be the way forward.

Clay plaster also has a major advantage over gypsum in older buildings in that it is not hygroscopic. It is breathable (so it lets moisture and water vapour pass through it), but it does not collect moisture like gypsum. Many of these older properties you will find damp patches where the gypsum plaster has swelled up from excess moisture in the walls (through rising damp, wind driven water ingress etc.) Once damp they will stay damp, so you will need to remove them and replaster (hopefully this time with a suitable product like clay or lime).

Clay plasters are:
100% natural and non-toxic
100% biodegradable
Lower in carbon
Natural regulators of internal humidity and temperature
Help to absorb toxins and also neutralise odours
Beneficial to those with allergies and sensitivities
Easy to apply, maintain and repair

So clay plastering, how does it work? Well, basically it is a direct replacement for a skim coat of gypsum. Applied with a plastic edged trowel up to 4 or 5 mm thick is creates a natural finish for your walls. It now comes in a range of finishes from Clayworks (and available through the Eco Home Centre). A standard finish (for painting over) a coloured finish or a mica enriched finish for that added bit of class.

The clay is very forgiving as a material, so if you are not happy with one piece, just go back whenever, wet it up and re-work it. Simple. Once you are happy with the finish simply use the EarthBorn Wallglaze to give a breathable finish that will stop any dusting of the surface (an old complaint from architects and designers - well no more!)

To reduce postage costs the plaster is supplied in dry powder form, so it is just add water and go.

I have a client who is keen to try the plaster in her new home and so we are looking to run a clay plastering course in the near future and so if you are interested please let me know at the centre by emailing

Costs are important of course, so per 25kg bag (enough for 7-8 sq m at 2-4mm thick):
£39.40 - £43.90 for pigmented Mica top coat (dependent on colour)
£34.80 - £39.10 for pigmented top coat (dependent on colour)
£21.50 for plain top coat
£17.90 for a fibre base coat (if required)

Costs are exc. VAT and delivery.

Friday, 30 September 2011

Barn conversions and the system

Wales is home to a large number of barn conversions. The old stone barns look really attractive in their rural setting and the materials used create the local vernacular. The old stone walls are the main feature of the barns and so the planners are really keen on keeping up appearances and so insist on minimal changes to the exterior.

All of this sounds fine, but here we hit a problem in upgrading these lovely old buildings from being an agricultural one to a domestic inhabited one. Modern building regulations state that you need to bring the thermal insulation of the building up to 21st century standards. Again this sounds fine, but the trouble begins with our dependence on computer modelling and building 'science'. We have created a system where we believe that thick solid walls perform really badly compared to modern cavity walls with inbuilt insulation. Recent tests from the BRE (Building Research Establishment - the be all and end all of building science) show clearly that solid walls do not all perform the same. It has taken to 2011 to find this out!!

At present all solid walls are treated as having a U value of 2.1. A U value is the measure of its thermal performance and the lower it is the better. Modern houses are allegedly built with walls of a value of 0.3. Barn conversions need to achieve 0.35 (why heaven knows!). However this BRE research now says that solid walls have a U value range of between 0.7 and 1.6. Nowhere near the 2.1 that appears in all the architects, building control and EPC software. So effectively we are making old buildings out-perform new modern buildings purely by using the wrong figure in the computer software.

This could be taken as a positive thing. Your barn conversion out performing a modern house. Marvellous. However, in order to get a figure of 0.35 from a 'starting point' of 2.1 takes a lot of insulation. Space in barns can be tight and so people are almost being forced to choose high performance insulation (phenolic boards, Expanded Polystyrene etc.) These boards are placed in a frame built off of the irregular walls and hence create four things.

1. A gap behind the insulation which is ideal for rodents, bugs etc
2. An thermal isolation between the old walls (with their thermal mass) and the modern living space
3. A non-breathing barrier between the internal plaster / insulation walls and the stone wall
4. A visual barrier between the inside and the internal face of the stone wall

So not only do you have a warm space for mice and other things to live in and nibble away at cables etc, you have effectively isolated the stone wall and all its thermal mass from the living space. So you cannot see what is happening there, you cannot see any moisture or damp problems, you have to manage the warm moist air in a mechanical way rather than relying on the breathable wall to do the work for you free of charge and the wall is being put in danger by being colder and hence more susceptible to interstitial damp.

This isolation of the wall purely to get the correct computer derived U value that is based on a false premise can therefore cause many more problems than it solves. The system and our reliance on factually incorrect assumptions built into software is therefore a major issue that needs to be addressed. Maybe the new Building Regulations in Wales will take this in account!!???

We think that ideally the walls of these old barns are not isolated by non-breathing insulation, rather that they be insulated with a material that adjoins the wall to maintain the solid nature of it and also maintains breathability. There are a wide variety of materials that can achieve this. Wood fibre insulation, hemp/lime plaster, insOwall insulating plaster, Sheep's wool boards etc. etc.

Even if we keep the 2.1 value (although I see no reason why we should) it is possible to get to 0.35, or to a figure for the whole house that takes some of the pressure off of the walls, by using natural materials that will work in harmony with an old building. For example increasing the thermal performance of the floors, doors, windows and ceiling will allow for thinner insulation on the walls. We really advise that you look at your project holistically and really aim to maintain the true nature of the building by using the right materials that will deliver you a long lasting, healthy, comfortable and cheap to maintain home.

Wednesday, 28 September 2011

New 50% recycled pipe from Wavin

A friend of mine works for Wavin. A huge company that sell drainage systems amongst other things. He has just popped around with a new set of products called Recycore Technology. What they have done is to encase recycled plastics into virgin plastics so that the pipes end up with a 50% recycled content.

Up until now all pipes had to meet a standard that demanded the use of virgin materials, but they have changed the Kitemark standard so that they can use recycled materials, but get the same performance and quality and the same price. Win win.

So if you are looking for drainage products either above or below ground then it might be worth stipulating a recycled content as otherwise it will probably be the same old virgin plastic products. More info is available from

Loft insulation by grant aid

Having recently been in a few lofts I have noticed the activities of a few naughty people. So by sharing this knowledge I hope it will be of advantage to anyone looking to have their loft insulated through a grant scheme.

The grant schemes have been very popular and rightly so. They have their limitations (no insulation for sloping ceilings, flat roofs, solid walls etc) but nevertheless for many people they have been useful and successful. Some of the costs for the grant schemes have not all been favourable and certainly they have not taken into account anyone looking to use eco-friendly insulations or very breathable solutions. It does seem to have been mineral wool, mineral wool (some glass fibre) and some more mineral wool. Great if you are a manufacturer like Rockwool or Knauf, but not so good if you are a recycled paper, hemp or sheep's wool insulation supplier or manufacturer.

The main point of this post though is to say to people PLEASE CHECK the work done. Two of the lofts I have been into have had the required level of insulation around the loft hatch (270-300mm - around about a foot), but this has tapered off the further you went away from the hatch. Perspective means that it can look OK, but closer inspection showed that the level at the edges / eaves was around 100mm rather than the 270/300mm prescribed.

It might be laziness, it might be greed, but whichever if you have paid for a job to be done, it is best to inspect it (or get a friend / family member to) as it might not be as good as it could be.

Wall paper and Eco wall covering

I have been busy removing old wall paper from an old lime plaster wall at home and I have discovered that:

a. Non breathable paint sticks very well to wall paper
b. Wall paper paste as a tendency to stick very well to plaster

I am now back to bare walls and I am glad to be rid of the wall paper.

Wall papers come in a great variety of types, textures and finishes and so getting the right sort can be an issue. However there are some basic principles:

1. If you are trying to preserve a breathable wall structure then I personally would look no further than a lime or clay plaster. These can be left as a feature (especially the clay plasters that come with lovely mica enriched finishes) or painted over with a breathable paint (clay paint for example)

2. If you want a paper finish to cover over roughness etc then use a FSC sourced lining paper and again use a breathable paint finish.

3. If you don't have a breathable wall then you can use any wallpaper, but again we would recommend looking for the FSC / PEFC mark.

4. There is such a thing as natural wall paper paste. This is effectively cellulose fibre. It looks expensive, but it goes an awfully long way.

Building Extensions - Cavity wall insulation

Many people are staying in their homes at the moment rather than moving and this has meant that there are more and more extensions going up around the country. This is great in a way as it means that people are starting to treat their houses more like homes and investing in them and their communities.

Most of these extensions will be built using brick and block with a partial fill cavity insulation. Most people will use a phenolic board as it is gives the best insulation per cm of the common insulation materials. These boards are undoubtedly good at insulating, but they do have some issues that you need to be aware of:

1. They are not recyclable. So effectively we are just storing up a waste problem for the future generations to deal with. So I think that their use is quite shortsighted.

2. They need to be fitted correctly. Most builders just put the boards in the cavity and tie them in with the wall ties and possibly a retaining clip. However many do not tape up the joints between the boards. Not taping up and / or not using a retaining clip radically reduces the effectiveness of the boards. Without them them are just knocking around in the vented cavity. This seriously affects their performance in the real world. So we would recommend that you inspect the work done by your builder to ensure that all the insulation is clipped and taped and that there is a continual strip of insulation around all of the house.

3. Buildings are designed to just meet building regulations, so for the sake of a few extra pounds you could specify a 75mm or 100mm board rather than the 50mm. Building in efficiency is so worthwhile for all of us.

4. Look at using low conductivity wall ties (for example Teplo Ties). These stop the cold bridging that occurs with using the conventional steel ties, plus they will not corrode. Using these types of ties allow you to have a larger cavity (to get more insulation in) and also reduce heat loss (tests have shown this can be around a 10% heat saving of the thermal loss through the walls)

We would recommend creating breathable walls (by using products like Durisol, timber frames with breathable insulation - Tradis system for example) as they are generally natural / recycled and recyclable products that are safe for you and the environment. Breathable systems create a better internal environment and can be equally as insulating as the more conventional materials.

Friday, 23 September 2011

Applying lime render, some tips

Lime can be difficult to get to grips with and use properly, especially for DIYers who might be more used to cement. Lime putty takes a bit more understanding than cement as it sets in a different way. Hydraulic lime, though, is a bit easier to use as it works in a similar manner.

There are some common tips for lime putty though:

If using a pre-mixed lime putty (which hopefully you will be) you will need to 'knock it up' before use. Here you will need to use a flat bed mixer, or just manually pummel the mix to ensure that the putty is spread in an even manner over the aggregate (hopefully not sand) with a fairly consistent moisture content.

Getting the mix right can be a bit hit or miss as it will depend on the substrate, the weather, location etc etc. There is no better tool here than experience, so it might be good to talk to the lime supplier about how their particular mixes work and get some pointers as to their thoughts on your particular situation.

Lime likes to be put onto a moist surface rather than a dry one otherwise it will not adhere properly this is because the underlying substrate soaks up the moisture from the mix immediately, thus drying it too quickly and creating a dry zone between the render and the wall. Thus there is no bond.

Ideally render putty render should be thrown or pumped onto a wall. This can be difficult in a DIY setting, but I have just used my bare hands (although gloves are recommended). So set down a load of sheeting around the work area and throw it on. Working the render with a trowel can pull the lime away from the substrate and so try and keep any working of the render down to a minimum.

It is better to add layers of lime render (assuming that you are doing a scratch coat as a first layer) when the lime is still 'green', i.e. it has not dried out completely and the top surface is still just about workable. This stops the creation of independent layers and will create a more consistent render. If your lower layer has dried overnight  (for example) then a tip is to wet down the scratch with some limewash and then add on the next layer.

To get a really smooth finish on the render (for internal work) you can use a lime plaster mix (this has smaller aggregate particles) over the top. Again you should apply this to the underlying render when it is still green. If you want a silky smooth finish (like gypsum) you can either put on a thin coat of pure lime putty or use a clay plaster.

Finish off the internal walls with a clay paint or a limewash, or you can glaze it up using earthBorns Wall Glaze. This stops dusting but maintains a breathable finish.

Finish off external render with a limewash. Using limewash helps to protect the render as it effectively forms a wearing layer. However if you have used lime putty with a breathable aggregate then it should last many many years as the whole system works in harmony with itself.

Be careful with using lime as it is caustic and we would recommend consulting with an experienced lime putty professional to get the right mix etc first of all.

Thursday, 22 September 2011

Trickle vents? A necessary draught in an energy aware world

Every house needs ventilation, after all we need fresh air to breathe and we also want to extract stale air to remove excessive moisture, smells etc. However we don't want gales blowing through the house taking away all of our precious heat in the winter. The trick with ventilation is to control it.

In the UK we have a history of excessive amounts of uncontrolled ventilation (draughts) through poor fitting doors and windows, old chimneys, floorboards etc. so in our haste to improve our homes many people have blocked up chimneys, replaced floorboards with concrete and fitted double glazed windows and doors. On the face of things, all of this is fine. However some rooms can suffer.

Bedrooms, bathrooms and kitchens are all subject to high levels of humidity at different times of the day. Cooking, washing and breathing may be all well and good, but they do leave a house with lots of water vapour to deal with. Kitchens and bathrooms are required to have extraction systems and this can deal with most of the humidity, however bedrooms are not and hence can find it more difficult to remove excess moisture. This is where trickle vents can come into their own.

Where new windows have been fitted without trickle vents you will often see condensation starting to occur. This in turn can cause mould. Whereas, where trickle vents are built in, the fresh air that they bring in and the stale air that they let out allows the room to feel much healthier and also reduces the risk of mould.

The balance then between losing heat and gaining fresh / extracting stale air is one where energy efficiency loses. Trickle vents are therefore an important element for most houses to possess. There are of course other systems of ventilation (whole house ventilation systems etc.), but for most people this passive style of ventilation is the most common and the appropriate for their home.

Radiator reflectors, any good?

You can buy a range of difference radiator reflectors in DIY stores. The basic idea is that they reflect heat away from the wall behind the radiator and hence keep the warmth in the room. This all sounds great, however, like with many things in life there are some additional pieces of information required in order to get it right.

The panels can and do reflect heat, however the best course of action is to get the warm air circulating from behind the radiator and into the room. The panels that have a serrated profile do this, whereas the sheet / roll type do not. So if you are buying a reflect why not get one that does both jobs well.

The second point is where to put them. Putting them behind radiators that are housed on internal walls does not really help as they only allow the room to heat up quicker and hence cool down quicker. If the radiator was left 'untreated' then the wall behind acts as a thermal store and absorbs some of the heat when the heating is on and then releases it again when it goes off. So the only real area where these reflectors earn their money in on uninsulated external walls. So if you have a solid walled property that is not insulated or an unfilled cavity wall then it will be a wise investment to use these panels here.

The profiled reflectors are available on line from companies like HeatKeeper. Their panels do not require radiators to be removed and so the process of fitting is very simple.

LED bulbs - are they any good yet?

I have just popped some new LED bulbs into the kitchen and bathrooms and am well impressed with the light that they are giving out. The ones that we used were the GU10 (halogen spot replacements) and are rated as 6.5w (although they are 5 x 1w high output LEDs).

The important thing with light is the colour and the lumen output. These bulbs have an output of 450 lumen on the cool white version (6500k). This is actually greater than the 50w halogen that they are designed to replace. Warm White is approx. 3000k)

However these particular ones are slightly larger than a halogen bulb at 70mm long (to accommodate the cooling fins), but they look great on free standing lighting bars and would also fit the majority of recessed fittings.

Excellent colour rendering index (around 90% - so very similar to conventional incandescent bulbs and a lot better than the energy saving CFL bulbs) a 50,000 hour expected lifespan (although it must be remembered that the testing regimes vary and you tend to get very good values at lower temperatures), a 2 year guarantee, available in 45 or 60 degree flood angle and not too bad on the wallet.

This quality of bulb used to be around £30 about a year ago, but these ones are now retailing for around £ 16 inc VAT.

I have been so impressed I think that we shall start to stock these. I can certainly access them on a next day basis if required.

Wednesday, 21 September 2011

What a difference a brush makes

Just a short post today. We are helping a family to refurbish their home in Cardiff by installing thermal and sound insulation in their 1980's built house. We have done this with Sheep's wool insulation and wood fibre boards. The effect is amazing and the house now feels so much more solid and quiet.

Anyhow, our tame builder has been doing the finishing touches (i.e redecorating the whole house!) and came to me complaining about the natural paint - he could not get the finish he wanted with the cutting in (edges etc). One look at his brush and I knew the problem. He had his trusty old brush that had done many years of hard service, but it was looking its age. We then supplied him with one of our Ecoezee Angle Sash brushes and sent him back to work.

I then get a text within a few minutes stating 'I am in love. With a brush!!' The results have been excellent and he is again a happy builder.

When using natural paints it is good to know that despite them being very similar to use to conventional paints (but without all the nasties) they are thicker and using a brush with a mix of recycled synthetic fibres and natural bristles is the best way of applying with a brush. Rollering should be done with a medium roller (10mm).

Happy painting.

Tuesday, 20 September 2011

Showers and ways to reduce their water use

There are a variety of ways of reducing water consumption in the shower, some automatic as well as manual, some are controllable, other not. Some work on electric showers, others only on domestic hot water (DHW) systems. So it can all start to be a bit confusing, so I shall try to bring a bit of clarity (or at least spell out the options).

The cheapest way to saving water is to just turn off the shower when it is not needed. So get yourself wet, have a good lather and then rinse off. However most people choose to have the shower running all the time to experience warmth and refreshment. But this option does not mean changing your shower, so no expense and it will have a similar effect on your water consumption.

Electric showers are generally already rated in such a way to have a certain flow rate so fitting new shower heads to electric showers will not normally save a lot of money or water. However they are produced, but be aware that most shower heads are designed for DHW based showers, so don't waste your money on the wrong equipment.

If you are installing a shower then we would generally recommend using the DHW system for your hot water this means that you can maximise any water coming from solar thermal panels (either now or in the future) and it is also generally cheaper to run and also gives a better pressure. However we would also recommend that you insulate the pipes going to the shower as you do not want to lose the heat on its way from the boiler / tank to the bathroom. If your tank or boiler is a long way from the shower, then an electric one might be better as the 'dead leg' between the heat source and use will mean that a lot of water is wasted (as well as heat).

So onto the mechanical ways of reducing water use. There are three main types:

1. Restrictors
2. Aerators
3. High frequency pulsators

1. Restrictors - these have been given away for free by some water companies. They are 'in-line' equipment that fits into the water output that just reduces the flow. These are a cheap and easy way of reducing flow, but be careful. Reduced flow can easily lead to 'cold feet'. Because of the low flow the water cools quickly and by the time it reaches parts of you it can be much cooler. The shower then becomes much more functional and less pleasurable as it takes longer to rinse etc. So these are really for the die-hard showerers who see it as a means to an end.

2. Aerators - these effectively draw air into the water mix and create a 'champagne' effect that makes the water feel bigger than it really is. These then get away from the cold heat and the water is effectively increased in volume. These shower heads can come with a variety of settings and are the most popular types of water saving shower heads. However the thing that they never tell you is that they are quite noisy.

3. High frequency pulsators - one company makes these and effectively it has a pressure system in it that releases a flow that switches on and off 30-40 times a second. So you don't notice the change in flow at all, however it also has the effect of reducing surface tension and thus making the water wetter, so you get a better shower. So where the aerators create a champagne effect this still gives the more traditional shower pressure and feel. However it also is loud.

So to reduce water consumption in the shower does mean compromise somewhere. Either in making the showering experience just functional (restrictors or turning off), bubbly and loud (aerators) or loud (high frequency pulse).

The most well known / regarded manufacturers are:
Aerators - Ecocamel, Oxygenics, Mira
Pulse - Nordic Eco