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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

Friday, 16 September 2011

Is lime, lime?

I, among many other people and organisations, bang on about the need to use lime products on older buildings, but what do we mean by lime?

There are many different types of lime:
1. Hydrated lime
2. Lime Putty (soft and hard)
3. Hydraulic Lime (different strengths available)
4. Cement (different types available)

1. Hydrated lime is not really a lime in the sense that it can be used to create a set mortar or render. Instead it is added to a cement mix to help ease workability. So do not use hydrated lime to make up a 'lime' mortar or render, you will require a cement to allow it to set.

2. Lime putty is the older form of lime. It sets by carbonation (so it takes back in carbon dioxide from the air in order to set) and is the softest and most flexible form of usable lime for mortars and renders. It is also the most breathable. So for these reasons it is often the best option for conservation work. However it should be used with the right aggregate. We recommend it being used with carbon rich aggregates like limestone, but it can also be successfully used with insulators like hemp. It should not be used with sand or similar materials.

Lime putty is created by heating up calcium carbonate (chalk or limestone) and then slaking it with water. It is then covered with water and the longer it is left the better it becomes. It comes in a putty format and so mixing it with aggregate requires a flat bed mixer rather than a conventional mixer as it needs to be smeared over the aggregate.

The difference between chalk and limestone sources is marked. So if you are going to use the lime in a highly damp area we would strongly recommend using limestone derived putty. The chalk one will not last.

For the external use of lime we would recommend using lime putty as being the most breathable form of lime it will draw out any water from the main walls to the outside.

It is worth noting that the lime needs to be applied correctly. Ideally it is pumped onto the surface not troweled on. Troweling putty on can draw the putty away from the substrate and hence not make as good a bond. Also note that if rendering the various layers of render need to be applied when the lower coat is still 'green'. If the underlaying coat is dry then you can get a poor bond and layering can occur.

3. Hydraulic lime sets through hydrolysis (if needs water to set) and so can set underwater. Hydraulic limes come in different strengths (normally NHL 2, 3.5 and 5) NHL 2 is the softest and 5 the hardest. These are less breathable than lime putty and are commonly used with sand. They come in bags of powder similar to cement. This is because hydraulics are essentially softer versions of cement. Personally I think that great care is required when choosing hydraulic lime and I would also recommend using a breathable aggregate rather than sand.

No doubt hydraulics are easier to use than putty and that this has meant that they are much more common (builders use them in the same fashion as cement). They are more expensive than putty to buy, but the labour costs and skills associated with them are less.

4. Cements are the most common binder used in building today. They are cheap, easy to use and are regarded as being the hardest, strongest and hence the best (I think that we do live with a male dominated construction industry). However their strength is also their downfall. They are brittle, cannot expand over any great distances without cracking and are not breathable. So they can easily allow water into a structure and then lock it in. This makes walls damp, inefficient (decreases energy efficiency by approx. 30%) and also destroys the underpinning structure if used on an old building.

If using on a modern cement based building then their use is fine, but ideally I would always recommend using a real lime product if possible. By 'real' lime I mean putty.

I hope that this helps you with understanding the 'lime' world. We have found that there are frighteningly few people who truly understand lime, even CADW struggles! So if you want some guidance on contractors please contact the Eco Home Centre.

Wednesday, 14 September 2011

How to improve insulation in the loft when you have it full of stuff already.

This is a big problem. Insulation companies will not remove all your stuff to install new insulation, so effectively by having a load of storage in the loft, stops you from having a grant for additional insulation.

So your choices. Well you are limited a bit, but you can still install insulation in the rafters. You need to leave a 50mm minimum air gap below the felt and down to the eaves to allow for air circulation to reduce the risk of condensation on the underside of the felt. So the easiest way is to attach insulation boards to the underside of the rafters. Most people here would use a phenolic board like Kingspan or Celotex. Personally I would recommend a wood fibre board. Have a look at the post on decrement vs insulation for the reasoning behind this.

This then turns your loft space into a bit of a half way house. Part insulated from below (normally with the existing 100mm of mineral wool or glass fibre) and then insulated from above by the, hopefully, wood fibre boards. This creates a better storage area as it will not suffer as much from the extremes of hot and cold.

Please do not fit the thin reflective insulation unless you are prepared for a lot of careful detailing work, otherwise you are wasting your money. These require conventional insulation behind them (50mm) and two airtight layers above and below the actual reflective insulation. Getting airtightness can be difficult at the best of times let alone twice on the same job.

If you were happy to move stuff around and create clear areas to work in, you could 'lift' the floor up, insulate below and then refit the floor. This does add weight to the floor load, so you need to be a bit careful depending on what you are storing, condition of joists, depth of joists etc. It will also make the storage area in the loft prone to greater temperature swings. One could also replace the boards with insulated boards. These are available as chip board with phenolic insulation stuck to the bottom. So same issues as 'lifting' the floor apply here.

Don't think that by having loads of stuff in the loft it actually helps with the insulation, because it doesn't (unless you are storing lots of duvets up there!) So have a think about what you are prepared to do and then make an informed choice. Remember that modern day standards suggest that you have 270mm (a foot) of fluffy insulation in your ceiling.

Light tubes / Sunpipes. Useful in the home?

Sun pipes or light tubes are effectively holes in your roof connected to a ceiling inside. They are designed to bring in natural light into otherwise dark areas of a building. This is of course the best quality light free of charge when the sun is up. So it all sounds great. And it can be, however there are some points to bear in mind and some simple tips that can make a world of difference.

Firstly, how often are you at home during the day. For many people are at work, school etc when the sun is shining and the light pouring in. Weekends for most are different and the light provided by the sun tube can be tremendous. So weighing up cost vs usefulness is important

Secondly, there is a huge difference in quality dependent on which system you buy. Please don't be fooled by the cheap flexible tube varieties that are on the market. Yes they are cheap, but unless you are doing the absolute minimum distance between roof and ceiling I would not entertain them. So anything more than 1m distance I would avoid this type and look at the solid tubes. These again have different reflective indexes, so if you are really short on light and want to maximise it then make sure that you are ask about this and get the appropriate one.

Thirdly, you can make sun tubes into light fittings. So when the sun isn't shining one can still use the fitting as a light.

Fourthly, be aware that you are effectively putting a thermal bridge between the ceiling and the roof. If your loft is insulated at ceiling level then ensure that you wrap up the tube in the loft with some sort of insulation to minimise the heat losses.

Fifthly, there are systems that are specifically designed for bathrooms that have extractors built into them. So if you are 'lighting up' a loo then you can have a system that provides you with a light fitting and extractor all in one.

Hope that this helps.

Tuesday, 13 September 2011

Guttering - which material is best?

As a supplier of Lindab guttering we had to go through the pros and cons of using steel vs aluminium vs copper vs plastic. This is a complicated route to follow as they all have different characteristics that can be hard to compare.

There are all the issues of: longevity; embodied energy; availability of resources; recycled content; recyclability; cost; ease of installation; robustness; manufacturing base; stability of the product; noise, etc.

To put the case for each:

Steel (Lindab)

PLUSES - recyclable, recycled content, stable, long lasting, abundant resource, easy to install, very robust, European manufacturing base, cost

MINUSES - noise, embodied energy of steel


PLUSES - recyclable, recycled content, stable, long lasting, abundant resource, easy to install, very robust, UK manufacturing base, cost

MINUSES - embodied energy of aluminium (one of the highest), cost, attractive to crime


PLUSES - recyclable, recycled content, stable, long lasting, easy to install, very robust, European manufacturing base

MINUSES - very high embodied energy of copper, limited resources, very expensive, very attractive to crime


PLUSES - recyclable, European manufacturing base, cost

MINUSES - low recycled content, not stable, short lived, fiddly to install, weak, high embodied energy of plastic, poor design


The metals are by far the better materials, but aluminium and copper are very expensive (and hence attractive to criminals) and steel does the same job. The plastics are awful and should never be used for such an important job, so we would recommend using Lindab. They have also done their eco-footprint calcs and it is very favourable.

Making old electrical appliances energy efficient

Most new appliances are energy efficient. They have circuitry in them that means that their energy consumption is kept to a minimum and they also have higher levels of insulation (for fridges, freezers and cookers) where appropriate. So buying new appliances is a good way of reducing your energy consumption when needing to replace old, broken white goods.

However there are instances where buying new is a costly and unnecessary expense. Large freezers can go on for years and replacing them can be very expensive, so what to do with the energy consumption?

Thankfully there are a couple of ways of doing this. The main inefficiencies (apart from lack of insulation - and this is more difficult to tackle) are due to the lack of control circuitry that reduces the power drawn down to start up the pumps and then smooths out the current to provide a more efficient power flow into the motors. However, if you have these technologies already installed then you will not benefit.

The most well known product is called Savaplug and it fits onto fridges and freezers. A list is available here of the makes and models that will not work with Savaplug.

Another system is hard wired into your electrical mains. This is made by V-Phase and claims up to 10% savings. These systems are being trialled by some housing associations and so some meaningful data should be available soon, but the company claims lots of independent testing and successes. This system works by reducing the voltage in the house down from around 250V to 220V, as most appliances will work at this lower level. Their product has been designed for the domestic market, so it will be interesting to see if they get anywhere near the saving that has been accrued by the commercial sector.

Other systems claim that they can 'treat' whole ring mains, so everything plugged into a circuit. So for example if you have an old fridge and freezer in the kitchen / garage etc then you can just plug in Power Factor correcting device, however the claims of savings are not independently verified in the UK. These systems are based on industrial energy saving devices where saving are certainly available, however their effectiveness in the domestic market seems to be under a great deal of scrutiny.

Bathroom radiators and dual fuels

Many of us have towel radiators in our bathrooms - they are ideal for drying towels, bathrobes and the occasional piece of washing when it is raining outside. Marvellous.

But what about summer? I know it seems strange to think that it can be cool and damp in a Welsh summer, but having been here for 20 years now there has been the odd occasion. So what happens to the the towels then? Using a damp towel is not the nicest thing after a hot bath or shower, but of course the towel radiator is not working.

This is where dual fuel radiators come into their own. Having a radiator that also has an electrical heating element to create a good drying space is a great addition for those rare days when using the washing line is out of the question or where you just want a warm robe to get into.

As an Eco DIY blog I should be saying that you just grin and bear it (and this is of course true), but there are those people who want their luxuries, have their PV panels etc and this is a way of ensuring that you can have another little treat.

So if you are renovating your bathroom / heating system / rewiring etc then it is worth bearing in mind the option of putting another circuit to the bathroom to facilitate a dual fuel radiator.

Wednesday, 7 September 2011

How to improve sound insulation between floors

Sound insulation is a whole science on its own, but in essence is a way of trying to reduce sound transmission of two main types of sound: Impact and Ambient

Impacts are the lower frequency sound waves that are caused by things like footsteps whereas Ambient tends to be higher frequencies associated with chatting, TV, radio etc.

The basic treatment for sound is using heavy weight mass. Basically this mass takes more energy to move and so sound is absorbed into it and hence deadened. However getting mass between floors is quite difficult. People have used ingenious and often daft ways of dealing with it. Pouring sand inbetween the joists for instance is an excellent way of reducing sound, but not so clever when sorting out any ceiling problems!

So given that mass can be an issue, how else to tackle sound? Well we have to be clever and look at using a range of products that absorb the different frequencies of sound. Mostly in homes we are looking at ambient sounds and these can be treated by using a mix of higher density materials coupled with lighter fluffy materials that will muffle higher and mid range frequencies.

The key ways of reducing sound between floors are:

1. Reduce incidence of impact sound - by having carpets rather than floor boards reduces sound creation, the impact noise made by two hard surfaces (floor and shoe) is greater than that made by a soft and hard surface.

2. Introduce a rubber strip / cover between the floor and the joists. This can be applied where you are replacing the floor boards (and maybe want to keep them exposed). There are two main options here. A. to just apply between the joist and floor (strips of rubber) or B. to use a whole acoustic sheet across the whole floor (either under or over the floor boards)

3. Install insulation between the joists. This can be any insulation, but the more dense the better, so look for the kg per cubic metre figure. Some natural wood fibre insulations can be as high as 80kg/m3, but most are between 25 and 40 kg/m3. Conventional insulations are also available and most have an 'acoustic' version. Remember here that you need to leave an air gap and not fill up the whole space as by leaving an airgap it provides a void that doesn't transmit resonances between the different materials.

4. On the ceiling you can increase mass by using woodwool boards (these come up to 50mm thick!), but most people will install a double layer of plasterboard. A double layer of plaster board does provide mass, but it can also amplify some frequencies as it is an even board with its own resonance, whereas the woodwool boards are not as even and hence their resonance is more complex and hence it absorbs sound better)

5. Ensure that there are no gaps in the treatment. Sounds have a great knack of finding holes and so you need to ensure that the insulation is even, the boards are taped, the rubber strips / sheets are taped / constant etc. So care needs to be taken around the edges of the room.

By having a range of materials in your floor you will help to keep the sound down as each material has its own role to play. They all absorb different frequencies of sound and so by having some 'fluffy' stuff and some heavy stuff and a range of interfaces between them you will radically reduce the sound transmissions between floors.

Roof windows or Velux?

Is a vacuum cleaner a Hoover? Is cellophane adhesive tape Sellotape? Is a roof window a Velux?

Velux are the leading manufacturer of roof windows, so much so that they have entered common parlance in the trade. This is due to their dominance in the UK market place, however there are other choices.

Fakro are very well known on the continent, but are rarely seen in the UK (although they are available through a number of larger Builders Merchants). However they are generally one step ahead of Velux. Their products are different in a number of ways and it is important to be up to speed with your options in order to get the best solution for your particular situation.

Velux are all FSC wood sourced, whereas Fakro are not (most of their products are FSC / PEFC, but a couple of ranges are currently not).

Fakro have a quadruple glazed option that are amazing insulating, whereas Velux have just brought out a triple glazed version.

Fakro handles are set at the bottom of the window whereas Velux are at the top. So for many circumstances where access might be an issue Fakro can be the better option.

So just be aware that there are other manufacturers that might have the product that you want. Also be aware that you might need to look at the fitting instructions to get the right collars to ensure that you get the efficiencies required.

Room heat recovery. Can it work?

With more and more people getting worried about heating bills one of the ways that is being highlighted to reduce costs is to use a heat exchanger on any ventilation systems. Basically they are designed to work as a way of using the warm moist air to preheat the cooler incoming fresh air by using a heat exchanger. This all sounds great, however at around £300 for a room based system do they work?

The basic answer to this is 'it depends'. Really helpful I know. To get to the bottom of whether it is right for you, you need to know the answers to the following points / questions.

1. Which wall is the extracted air being expelled?
2. Does the extract require a filter? (normally associated with a kitchen extract)
3. How airtight is the room in question?

1. The direction that the wall is facing makes a huge difference to its effectiveness. All extracts have fins on them that are designed to open when extracting air, however they are no match to the power of the wind. So if they are facing into the wind they will just be blown shut and hence stop the whole system working (this applies to all extractors, not just heat exchanger ones). So look to site your extract on an east facing wall or into a well vented roof void / eaves.

2. If you are extracting air from a kitchen area then you will need to have a good filter system to stop the sensitive heat exchanger from blocking up. So you will need to be prepared to have a good maintenance regime in place so that it can work effectively.

3. If your room is not very airtight then one must question the effectiveness / need for a heat exchanger as much of the air being lost / removed will not pass through the exchanger and so any good that the unit does will be quite minimal compared to the rest of the ventilation going on.

In conclusion I think that you should only look at investing in a room heat exchanger in the following situation:
Bathroom with an east facing / eaves extract that is well draught proofed.

I would also suggest that your driving force is not money saving, but to create a more comfortable environment when showering / bathing.

Heat exchangers are great in airtight new buildings, but they use is really limited in older homes (unless a major refurbishment is undertaken) and in this case you will be looking at a Whole House Ventilation System.

Spider plants, better for you than Spiderman

Sick Building Syndrome is a well recognised issue within buildings, especially in work environments where we tend to: use lots of electronic devices; have regular cleaning using powerful detergents; and be surrounded by off-gassing materials like plastics, MDF and foams. However these materials are also common in the home.

All the different chemicals that are given off by materials like formaldehyde, benzene and phthalates enter the atmosphere and in confined places like buildings their concentrations are much higher than in outside environment. So we are breathing in these chemicals and they can have a really detrimental effect on our health. They have been linked to a wide range of complaints from leukaemia to autism, so it is not something to brush under the carpet. It is especially important to protect children from these chemicals as they absorb them much more readily and in higher concentrations than adults.

So where do Spider plants come into all of this?

Well Spider plants are are especially good at absorbing some of these off-gassed chemicals, notably formaldehyde. So effectively they filter the air for us and lock up these potentially dangerous substances into their leaves and roots.

It is not just Spider plants though, biological studies have found that ferns are exceptionally effective in extracting arsenic from the ecosystem. It has been determined that, in areas which have been exposed to arsenic through industrial pollution, the arsenic fixing abilities of ferns could be as effective as the more conventional hazardous materials protocols.

A NASA research study arrived at the conclusion that philodendrons were also exceptional purifiers for formaldehyde and that Gerbera daisies also have the capability to extract benzene from the ecosystem.

So not only do you green up your home and make it look nice, you are also providing a natural buffer between you and the chemical soup that surrounds us at home. However we would recommend that you also reduce the amount of off-gassing materials at home (plastics, glued wood like MDF, synthetic foams in mattresses, sofas etc) and also look to use natural cleaners in minimal amounts.

So Spiderman has nothing on Spider plants when it comes to making your home and life that little bit safer and cleaner.