
This blog is full of really important advice from the Eco Home Centre. It can really save you time and money. Visit the Eco Home Centre page for details of our E-Shop for eco-DIY products. The Pre-purchase Inspections page sets out our essential service for house buyers or if you are improving your existing home visit the Individualised Home Report page. Eco Home Centre is a not for profit organisation based in Cardiff.
Friday, 24 June 2011
Treating external wood
The decision on what to use is largely dependent on a number of factors:
Has the wood already been treated with a product (stain, paint, varnish)?
What type of wood is it?
Will it be in constant contact with the ground / water?
How exposed is it to the sun and weather?
Do you want it to weather or retain its original look?
Is it located close to a pond / water, or will it be used in housing pets / bees?
If wood has already been treated it is important to know what it was treated with (so remember to make notes on this type of thing when applying as most people will forget over time). If the wood has an oil based coating it might be that you have to re-use this product (unless the product is really well weathered and the preservative has been really leached out of the wood). So for existing coverings your choice is now really limited if you want to go down the eco-route.
Some woods require certain treatments, so a hard wood generally requires a thinner preservative than a soft wood as the grain is tighter. Also some woods have natural tannins or oils that might react with certain products. So if in doubt use a wood oil that matches the timber. Larch oil for larch for example.
For timber that is to be in constant contact with the ground it is important to treat the wood prior to it being placed in situ. I would also recommend leaving any preservative to soak into the end grain overnight to really give this most exposed of areas a chance to soak up protection as much as possible.
For wood that is really exposed to the elements there is a need to use treatments that will help it to stop expanding, contracting, splitting and degrading. You may wish to protect the structure with a 'disposable shield' like some old pallets or plywood in really exposed conditions. Using really high quality treatments in highly exposed areas is important as it will save you a lot of time in the long run from having to re-treat every year. This is also true for locations where access is an issue.
If you want your wood to retain its original colour then using a UV stable treatment is important. Clear treatments are not generally UV stable as they have no pigment to protect from the UV light. However there are some companies who make clear treatments with a UV protector in. Notably Osmo.
Many treatments are not friendly to wildlife. They are designed to protect against things like mildew, rot and insect attack, so if you want a treatment that does not contain biocides etc then you need to be careful in what you ask for. Natural products are not necessarily safe for wildlife as nature has its own toxins. So using treatments that are safe for your pets / bees / ponds etc is possible, but you will sacrifice a certain level of wood protection unless you treat the wood prior to installation and seal up water based biocides with an oil top coat.
So what do we recommend?
Generally we look to Osmo for their wood treatments they have a huge range of products for all situations. Auro though do a very good water based wood stain range and the earthBorn Varnish is very safe to use although not as durable as the Osmo. For more info contact Osmo or the Eco Home Centre for advice.
Insulating solid walls
Nevertheless, with the need for carbon reduction, we do need to improve the efficiency of this type of housing stock (the old terraces, country cottages, barns etc.) So how best to do this?
Before we can start to look at options we need to understand how walls work and this involves looking at how they were made and what they were made of. For more info on this look at the blog below South Wales' VictorianTerraces - Home, House or Castle?
So given that we need to preserve breathability what can we use?
There are a number of options here, assuming that your house still has its breathability in tact. If you have cement render on the outside that is trapping in moisture, just by removing this and allowing the walls to dry out you will see a 30% improvement in the thermal performance of your walls (approx.)
The main options you have are based on where you can insulate. Insulation can be placed on the outside or the inside. Ideally you will look at external solutions. This keeps the thermal mass on the inside and also reduces any risk of frost damage to the outside (insulating on the inner walls reduces heat flow and can cause frost to come further into the walls).
External insulation options are:
Woodfibre boards (these are wood boards that are mechanically attached to the wall and then rendered over or overclad with timber / brick slips). Remember that you will need to use a breathable render and paint on the finish. For more info visit some of the suppliers websites. Eco Home Centre can access the best (and oddly the cheapest) system if required.
Lime render with added insulating aggregate. This can be vermiculite, perlite, hemp or just a stone dust. All of these are natural insulants and allow moisture to pass through. They can be applied in varying depths, but should be blown onto a wall rather than troweled. A specialist contractor should be employed for this. Eco Home Centre would recommend Welsh Lime Works or Vale Lime.
Internal insulation options are:
Insowall insulating render / plaster. This is a modern, but breathable, product based on lime and nano-technology insulating material that replaces render. So this is great where space is at a premium. It can be put on up to 40mm thick and will improve the insulation value around 70%. I have used this at home and been impressed by it. However read the instructions on the bag, as some conventional plasterers will try and use it like normal plaster. Can take a clay or lime finishing top coat.
Hemp render / plaster. This is a lime plaster with hemp as an aggregate. A good insulator, but needs to be put on quite thickly to get good values.
Sheeps wool or wood fibre insulation blocks. These are similar to the external renders, but designed for internal use. Mechanically attached to the wall and then rendered over.
Studding out the wall with timber and infilling with a natural insulation material like recycled celloluse, sheep's wool, hemp or flax. Remember here to use a wood wool board to provide your internal finish for plastering.
PLEASE, please, remember NOT to use conventional dry walling products like insulating plasterboards, phenolic boards etc. These are not breathable and can cause no end of damage to the walls by trapping in moisture and hiding any damp and mould.
South Wales' Victorian Terraces - Home, House or Castle?
Fed up with filler?
I have used conventional fillers over time and I have a love / hate relationship that tends to favour the latter. The biggest complaint is that, as an amateur DIY'er I am not so proficient at getting a smooth finish first time around. This in turn leads to me having to sand back the filler I have just put in to get an OK result. Sounds OK-ish, but the conventional fillers go rock hard and are a real pain to sand back. Not only that they are not so good at allowing moisture to pass through and so do not sit particularly well with my old lime plaster.
So an alternative is required. Thankfully there are a range of alternatives.
Auro do a superb internal filler that is based on talc. It gives a brilliantly smooth finish, but most important for me, it is breathable and easy to use and to sand back. It is still very hardy, but the fact that you can quickly sand it back if necessary is a real godsend to anyone like me who needs as much help as they can find when doing running repairs on a house.
Earthborn have a very similar product. Again breathable and easy to use and to sand back. However, the earthborn filler is based on casein and lime, so it can be used as an external filler as well.
Once you have used these products, you will never go back to a conventional filler.
Thursday, 16 June 2011
Water saving and its importance
- Your water supplier will send you a free water saving device to put in the bottom of the cistern, or you could equally well use a plastic bottle filled with water. This will take up space in the cistern, causing less water to be used in each flush. You may need to experiment with different bottle sizes to ensure that the flush still operates effectively.
- You can fit an Interflush® onto the siphon inside the toilet. This device means that you can regulate how much water is used for each flush by holding the handle down for as long as is required. This can save 47% on water use.
- A retrofit variable flush siphon can be fitted, again from Interflush.
- A delayed action inlet valve can be fitted. This prevents the cistern from refilling until the flush has finished. This will save approx. 2l% of a full flush.
Wednesday, 15 June 2011
Which paint for internal wood
Satin / eggshell finishes though are much easier to get with natural paints. These are mostly water based and give an excellent finish, however there are differences between manufacturers. Auro produce a great range of Matt Silk (and Gloss) paints based on orange and linseed oils, whereas Green Paints is based on Soya, whilst EarthBorn have managed to create an eggshell that is totally water based without any oils (ProAqua Eggshell).
So to the most important considerations.
For cost - Green Paints is the most competitively priced. A good quality paint, but it does take some time to cure, so I would not recommend in areas like door jambs, windows or on surfaces that will have heavy items on. I would also only use their semi-gloss. Also only available in a very limited range of colours.
For eco-credentials - Auro is a great manufacturer (carbon zero) that has a good range of paints. They even produce a natural paint suitable for exterior use - their High Gloss 935 paint. This does take a long time to dry to be aware that you will need to leave around 6 weeks to cure. A great range of colours though in their 250 and 260 paints.
For quick drying - EarthBorn ProAqua Eggshell is a must - dry in about 20 minutes and no smell at all. Totally VOC free.
On untreated wood - I would probably use the Osmo Woodwax Creativ range here. One coat for a translucent finish and two for an opaque one, but it does need to go onto untreated wood.
For application on pre-painted wood (not inc. Osmo), give the surface a gentle rub over with sand paper to create a key for the paint to adhere to and then you can either add an appropriate undercoat followed by a top coat, or (most people will just) add a top coat.
For fresh wood either use Osmo, or if using other types of paint make sure you seal any knots with a Shellac, then add an primer, undercoat and a top coat. EarthBorn ProAqua will act as a primer if watered down by 20%.
Wooden floor finishes
Most builders will use a polyurethane finish as this is cheap to buy, however they are not really cheap. Polyurethanes are commonly applied in a number of coats and in between them the surface should be lightly sanded. This give the 'key' for the next layer. So you will need to do at least two sanding tasks. First to get the surface level and prepared and secondly after the first coat (and subsequent coats). So this takes time and hence money.
As well as requiring more sanding there is also the environmental and social costs of using a smelly, high VOC, petro-chemical based chemical on your home's floor.
So an alternative?
Commonly people used a Hard Oil and then waxed this to give a wearing layer. These natural products work by allowing the oil to set rock hard in the wood to make it really resilient and the wax protects this with a disposable layer. This system also requires sanding between coats of hard oil and there is the on-going maintenance of the waxing.
The real alternative...
I believe the best solution is a Hard Wax Oil where the hard oil and wax are pre-combined. This has a load of advantages. Firstly it is simple, it is also very hard wearing and natural but possibly most important, it is economic. No need for sanding in between coats. Just prepare your floor (last sanding grit of between 120 and 150), put on a layer and leave to dry (this is between 4 and 12 hours depending on product), then put on another coat and leave to dry (12 hours). Done!
The catch?
None really apart from you need to put it on really thinly and this goes against the grain of those used to polyurethanes. If you put it on too thick it won't dry.
The best one?
Having spoken to a range of floor fitters they recommend Osmo Polyx Oil. Others on the market can leave tram lines on the wood where you overlap on application.
Which is the best lightbulb to buy?
With incandescent lighting slowly being phased out in favour of low energy lights how should be choose the replacements.
Well there are two main alternatives:
Compact Fluorescent Lights (CFLs) and;
Light emitting Diodes (LEDs)
Both of these offer significant savings over incandescent bulbs, but the choice is made more difficult because of the following factors:
- Cost
- Energy used (measured in watts) vs light emitted (measured in Lumen or Candela)
- Lifespan (measured in hours)
- Colour of light (measured in Kelvin - cool white @ approx. 4000k, warm white @ approx. 3,000k and daylight @ approx. 5,500k)
- Quality of light (measured in Colour Rendering Index - CRI with 100% being all colours of spectrum)
- Quickness of response
- Materials used in manufacture (many people have been scared by the mercury involved in making CFLs)
1. Cost
CFLs are cheaper, but as with most things in life, you get what you pay for. So there is a quality issue. Higher priced bulbs tend to be better made, last longer, have better quality of light and are resilient to being switched off and on constantly.
2. Energy
I tend to work on a factor of 4. So a 15w CFL is equivalent to a 60w incandescent.
3. Lifespan
This varies with cost, but the figures quoted on boxes are when 50% of a batch has failed, so some will last longer than say 8,000 hours, others will not reach this milestone. Megaman bulbs tend to have the longest lifespan of around 15,000 hours.
4. Colour of light
CFLs come in all main colour temperatures.
5. Quality of light
Here CFLs don't fare so well. There CRI tend to be around 70-75% so there are major areas of the colour spectrum that are missing and this leads to us seeing false colours that many people don't like.
6. Quickness of response.
Again CFLs fail a bit here as they take some time to warm up. They work better at higher temperatures and so their brightness increases after about 30 seconds.
7. Materials used.
Most CFLs use liquid mercury to work. This has given the scaremongers a great opportunity to worry people, but it does take some fairly unique situations to be any danger whatsoever from lightbulbs. Megaman have gotten around this issue largely by using mercury in a solid state rather than a liquid one.
LEDs
1. Cost
This is the main issue at present with LEDs they are expensive. You can get really cheap 1w bulbs but they are really worthless if you are looking for light as opposed to dash of colour.
2. Energy
This is a more difficult area, but they are generally more efficient than CFLs with a factor of around 6 to 7. So a 6w LED will give around 36 - 42w of incandescent equivalent, but LEDs are directional and so one pointing up gives less useful light that one pointing down.
3. Lifespan
This varies with cost, but the figures quoted on boxes are when 50% of a batch has failed, so some will last longer than say the average of around 25,000 hours, others will not reach this milestone. Some will claim a lifespan of 50,000 hours, but this might be due to the temperature that they are tested at. The cooler the ambient temperature the longer they will last.
4. Colour of light
LEDs can come in all main colour temperatures.
5. Quality of light
This is where LEDs can excel (although not all). Many LEDs will have a CRI of over 90% so giving a wide spectrum of colour and hence giving a much more accurate quality of light.
6. Quickness of response.
LEDs are instantaneous and so again are ideal for areas where instant light is required.
7. Materials used.
LEDs require more electronics to work and so have more internal circuitry associated with them, but they do not contain mercury or any other poisonous materials.
So recommendations.
Personally I would use LEDs where you want:
Instant light
High quality light
Where changing bulbs is difficult / expensive
OR where you will have lights on for very long periods of time
Apart from that CFLs will suffice and give you adequate lighting.
Applying and using natural eco paints
Saturday, 11 June 2011
Choosing natural eco paint
Friday, 10 June 2011
Repointing solid brick walls
What to do about leaky guttering
- Build up of leaf litter / dirt in the guttering
- Blockage in the downpipes
- Cracked or damaged guttering
- Poor seals between guttering lengths
- Misaligned runs
Plastic guttering is especially prone to these problems because:
Remedy
Keep your guttering clear from debris by having them cleared every couple of years (or more often if you have overhanging trees).Use a more stable and longer lasting guttering material. There are options available like steel, aluminium, cast iron and copper. At Eco Home Centre we recommend Lindabguttering because it is relatively inexpensive, easy to fit, well designed, stable, long lasting, easy to fit and can be incorporated into SUDS or other water collection systems.
Damp on internal walls at approx. 1 m above the ground
Mould and condensation issues
In high humidity rooms condensation can easily occur where there is not enough air circulation or where non-breathable paint has been used to seal up the room. Bathroom and kitchen paint is probably the worst thing that you can use in your bathrooms and kitchens because they seal up the room thus trapping moisture inside and this then can form condensation and damp problems.
Inadequate ventilation is also another major cause of the problem. The smallest (and cheapest) fans are the ones that are usually fitted in bathrooms and kitchens. They are not always the best choice, because they are the absolute minimum required, and this is not always enough. The issue with larger fans is that they use more energy and also increase heat loss. So getting the right size is important.
Where the extractors face is also important. If they are west or south facing they are likely to get blown shut by the wind and hence not be able to extract air properly. So it is worth placing them on the north or east walls to get the best performance and also to stop the incessant slapping of the vent's flaps.
If you are worried about heat loss then this can be partially remedied by using room based heat exchange extractors. However you do need to have a fairly airtight room / house for these to be anywhere near efficient.
A house needs good ventilation and in many homes this comes from trickle vents in the windows and so these should be kept clear.
Many people also dry their clothes on radiators. This just adds large amounts of moisture into the internal atmosphere and so should be avoided.
Condensation is also caused by cold spots in the house. This might be on walls, or on the windows (windows are less thermally efficient than walls). This is way radiators are commonly placed under windows to prevent condensation. So if there are cold spots then condensation is more likely here. This is a structural issue and should be addressed.
Remedy
Ensure that you have adequate ventilation in the house (appropriately sized extractors in high humidity areas) and that they are fitted onto a north or east facing wall. If you have a breathable house (many of the older buildings with solid walls are intrinsically breathable) then by using breathable paints onto the lime plaster then the walls will help to control the relative humidity in the house.Do not dry clothes on radiators (unless you provide adequate ventilation).
Where you are redecorating existing painted walls, you can use clay or chalk paints to help to ease the problem as they actively absorb and release moisture as humidity levels change.
Insulate where cold spots occur (or cure the underlying structural issue like thermal bridging). Where this is difficult you can use products like insulating paints or thin insulation like aerogels or insulating plasters.
Damp around chimney breasts
Rendering older houses
External render finishes to solid walled buildings (esp. brick & stone)
Many of our homes are rendered, but most are not rendered using the right materials. Older houses (mostly made with solid walls of stone and brick) used breathable materials and lime mortars to bind them together. This system allows the walls to take moisture from the inside to the outside thanks to a number of factors:
1. The outer walls have a higher surface area (rougher texture) and this naturally means that they dry quicker and hence pull moisture through from the inside.
2. Houses have higher pressure inside than out, so air pressure also helps to push moisture through from the inside.
3. The materials used on the inside generally are less breathable than those on the outside, thus creating a gradient of breathability through the wall that attracts moisture to the outer part of the wall.
These characteristics mean that these walls will naturally keep the inner walls dry whilst allowing the outer walls to take the brunt of the weather. The outer walls will get soaked and absorb moisture, but will also dry out quickly as well. With the depth of these walls being between 22cm and 100cm this is no problem.
Over time construction practices, training and materials have changed and the pressure is now about using materials that are quick, convenient, easy and profitable. Material choice for most builders is not about choosing the right one through research, but about what they know. Our older terraces and buildings therefore get the same treatment as a more modern cavity walled house. This means the use of sand and cement for re-rendering.
The basic underpinning principle to this choice is that by using a water-proof render you keep the water out. Rising damp is then 'cured' by the installation of a chemical damp proofing course. Internal moisture is removed by mechanical ventilation and it is hoped that there is no water ingress from above (through leaky roofs, blocked gutters, worn felt etc.)
Unfortunately if any of these elements are compromised (cracks in the render, failure of the damp proof course etc) then water can get in, but not out again. So what happens? The walls get wet and wet walls = much higher thermal loss = cold spots = condensation = mould. Internal plaster gets soaked and paint starts to flake and peel off. So just by using the wrong materials we can change the house from a dry and active building into one that is cold, wet and in danger of structural damage.
Remedies
The remedy that is right for you will depend on a range of factors, including whether your home has already been rendered, what state of repair it is in, how exposed the house is to the elements and your financial ability to get it sorted.
1. With existing uncompromised cement render
If the render is not compromised and you have no problems with rising damp or water ingress from above and your home is well ventilated and heated then you are probably OK and need to do nothing (except hope that it stays this way)
2. With existing compromised cement render (but not 'blown')
If your render is cracked (and the really small cracks are the worst) and you have found evidence of damp in the house then you have two real choices:
a. repair the existing render and accept that the walls will be wet and cold for a while
b. bite the bullet and replace the render (see below for recommendation on type of render)
3. With existing 'blown' render that needs replacing
Once the render has blown is really is only doing harm to the building by trapping water. Hacking off the render should be easy, in fact you might find too much coming off at once, so be careful! Make good any poor bricks / stone etc and re-render using the following render:
Eco Home Centre recommends the following basic render mix:
Lime Putty (derived from limestone rather than chalk) mixed with a breathable aggregate (limestone dust for example).
This mix should be pumped onto the walls (to get more air into it - lime requires carbon dioxide to cure / set) and you might need to look at putting a hairy scratch coat on first or a webbed membrane.
This is the most breathable lime render you can get and so will act as a poultice to dry out your walls and hence keep them dry and efficient.
Top coats for lime based / breathable renders
The final finish is also very important. If you are using a lime putty render then you should use a limewash finish. This is effectively pure lime putty and so is even more porous than the render. This acts as a great 'wearing layer' for the render. Being so porous it will get saturated really quickly and will then shed water off of the surface when it is raining. When it stops raining it will pull the moisture through from the render and allow it to evaporate away. Limewash does need to be reapplied every so often (around 4-6 years) depending on exposure, but it is cheap.
For lime renders that are made from hydraulic lime or by using sand (not recommended by us) then you can use a silicate paint. These are really hard wearing and provide an excellent long lasting finish. Silicate paints are expensive, but provide value for money through being so long lived.
For guidance on builders / contractors who we feel understand these issues and are experienced in using and applying lime putty stone dust aggregate renders please contact the Eco Home Centre.
For more advice and products please call the Eco Home Centre on 02920373094.
Disclaimer
Rounded Developments Enterprises Ltd have endeavoured to ensure that the information contained in this report is accurate. However, Rounded Developments Enterprises Ltd. accepts no liability for the use of this information.
Statement of Vested Interest
Rounded Developments Enterprises Ltd are a well-recognised supplier of a range of sustainable building products and as such have a commercial interest in some of the recommendations contained within the report. In some cases, cost estimates have been given on the basis of current quotations for similar equipment supplied by Rounded Developments Enterprises Ltd, and may not be the only equipment available. However, it is our opinion that the study offers an appropriate level of detail in view of the resources available and information provided. The authors have no expectation of any order being placed with them and would welcome questioning of the choice and costs of any equipment.