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Friday, 26 August 2011

Are solid walls really that bad at insulating?

For anyone involved in the world of building or DIY we are always being told that solid walled houses are really bad insulators. Certainly compared to modern theoretical standards of building the computer programmes tell us that old solid walls perform really badly on this score. However times are changing and people are actually doing some real-life testing on old houses to see if the assumptions built into the computer models are OK. Lo and behold where we have been told that all solid walls have an U value of 2.1 what we actually find in the real world is that they are generally between 0.7 and 1.6 (the lower the U the better the insulation value). This is still higher than modern building regulations (these require a typical U value of 0.3 for a wall), but also a lot better than we were led to believe.

So we find that solid walls actually perform much better than thought. Research is also now looking at thermal mass. This is the capacity of a material to absorb heat in times when the temperature of the air is higher than the temperature of the material and also its ability to release heat into a room when the temperature of the material exceeds the temperature of the air. Thermal mass can also work by absorbing the heat from the sun when in direct sunlight (passive solar gain) and releasing it when the air is cooler.

This ability to retain heat for long periods of time can help to smooth out the temperature fluctuations in a room / house, thus making it cooler in the heat of the day and warmer in the cool of the night. This is great in the summer (as long as you don't get too much passive solar gain as this can cause overheating), but still has the disadvantage of keeping a house cool in the winter (unless passive solar gain is used wisely).

So is there a way of having the best of both worlds?

Yes. Ideally solid walls are insulated (using a breathable insulation) on the outside, thus keeping the thermal mass inside and active whilst slowing the heat loss during the winter months. Wood fibre boards are excellent for this, as are thick insulating lime based renders.

Wood fibre boards are widely used on the continent and are readily available in the UK (if you know where to look). Contact the Eco Home Centre for access to these products. They are finished with a lime render and a suitable breathable paint (limewash / silicate paint) so in many instances the appearance of an already rendered / painted building will not change too much.

Insulating breathable plasters are more interesting. Just by using the right aggregate you can change the insulating value of a render. This is why we always recommend NOT using sand. Sand / crushed glass is a good conductor of heat and so doesn't really give you any added insulation value, however, by using a crushed limestone, a volcanic rock or an air filled aggregate you can improve the thermal performance. So think about an InsOwall plaster or a Lime product from the Eco Home Centre.

If you cannot insulate the outer walls then you can look at insulating the inner walls of the house.

Many people make the mistake here of using insulating plaster boards. Please do not! The alternatives are:

1. Use Hemp Lime plaster (this is a coat of render / plaster that has hemp fibres in them that act as a insulator)
Pros: follows the wall to give an original feel to the walls; cheap to buy; can be applied as a DIY product or by professionals; highly breathable (if using a lime putty mix); does not isolate the underlying structure; no void for flora or fauna to exploit; decrement value
Cons: Not a brilliant insulator so depth required to get a good insulation
2. Use InsOwall plaster
Pros: follows the wall to give an original feel to the walls; cheap-ish to buy; can be applied as a DIY product or by professionals; breathable; does not isolate the underlying structure; no void for flora or fauna to exploit; decrement value
Cons: Good but not brilliant insulator
3. Calcium silicate boards
Pros: Can be applied as a DIY product or by professionals; breathable; does not isolate the underlying structure; no void for flora or fauna to exploit; decrement value
Cons: Good but not brilliant insulator; cost; does not follow walls and so needs a regularising coat first
4. Wood fibre boards
Pros: Can be applied as a DIY product or by professionals; breathable; does not isolate the underlying structure; no void for flora or fauna to exploit; decrement value; variety of thicknesses to suit needs; can follow existing surface to a large extent
Cons: Good insulator; requires a flat surface ideally, or a regularising coat is needed
5. Stud wall with breathable insulation infill
Pros: Can be applied as a DIY product or by professionals; breathable; creates a new wall so does not need to follow existing wall
Cons: Very good insulator; cost; isolates the underlying structure; void for flora or fauna to potentially exploit; lower decrement value

So, overall solid walls are undervalued for the advantages that they bring, but they can still be improved upon to bring them into the 21st century. For more advice on this vital area of refurbishment please contact the Eco Home Centre.

Doors - Hard or Soft wood?

Doors are one of the most important elements to a house. The front door sets the scene and creates a first impression. Internal doors also have a strong influence on the character and feel of the inside.

So how to go about choosing the right material.

Many houses really benefit from having a solid but welcoming front door. Wood certainly gives off a warm and friendly impression, whereas many a uPVC door looks out of place. The plain colours of uPVC do not have the texture and feel of wood, although many manufacturers try to get this by careful moulding.

So when looking at doors should one plump for a softwood or a hardwood? To a certain extent this is not really important as far as looks are concerned as softwood can easily be stained to look more like hard wood, however there is a difference in strength. Hard woods are generally stronger than soft woods (not always the case) and also contain natural oils that help to preserve them against rain. Hard woods are also more stable (less expansion and contraction in different weathers). They are also better at taking fixings like screws as their closer knit structure provides a better key.

So when looking for a main entrance door a hard wood door is a better option as it will take the lions share of the weather and usage. However, it is important to know a couple of other things.

Hard wood can have a mind of its own. As moisture content varies in the wood a hard wood can bend and warp and there is little that can stop this. This can be combated though by using laminated doors. Here a number of thinner pieces of timber are glued together so that the grains work against each other to create a door that is dimensionally stable.

Once you have a door that is stable you need to ensure that it fits well into the frame. This is difficult if you are buying a door and frame separately, or trying to fit a new door into an existing frame. We would recommend replacing both so that you get a really good factory finished airtight seal and also all the locks, hinges and furniture working together.

Hard wood still needs to be protected to get the maximum lifespan out of the door. Use natural wood oils to preserve and protect the door, especially if it gets a lot of the weather.

Internal doors are a little easier as mostly they are not generally required to be draughtproof, insulating or weatherproof. They are also thinner and hence lighter, so less pressure on fixings etc means that soft wood is absolutely fine for interior fitting. So we would recommend using FSC (or PEFC) softwood for internal doors.

Flagged foors and how to protect them

Many old houses have tiled or flagged floors. Most of these were glazed when they are installed to give a hard wearing surface. However some quarry tiles were not and of course flagged floors are natural and hence not glazed. So how to stop them from getting dirt ingrained or from slowly being worn away by abrasion.

There are a number of product types that are available. Any quick internet search will show them up. However there are a few things to bear in mind when choosing:

Look for low / zero VOC products
You need a breathable / micro-porous seal as there is a constant flow of moisture vapour up through the floor
You need a finish that is not slippery / glossy

Most of the products will not give you a fantastic lifespan unless the tiles are not being stepped on. So be prepared to have to recoat the tiles every year or so in the high traffic areas. This can cause problems with some sealants, so again look for ones that can be re-applied over the top of existing.

Certainly the Hard Wax Oils from companies like Fiddes and Osmo are good candidates that give you all of the factors above.

Service voids and enclosures - worth thinking about

When undertaking a major refurbishment you always find that you have a mass of tangled electrical wires, pipes and conduits around the house. They run through floors, down and across walls. This is because over time people have renewed wiring, installed new equipment like electric showers, central heating etc. This all leads to a catalogue of independent changes that has left the house / building with a confusing and often awkward service connections.

So when undertaking a major refit we would suggest that it is worth bringing all the services together in a coherent manner. This not only tidies up what is there, but also makes the whole building more future-proof as one can make access to all the pipes, wires etc better and more readable. By also making some dedicated service voids with access points one can make it all cheaper and easier to maintain and repair as necessary.

Service layouts should also be kept in accessible places so that you can refer back to the layouts at a future date, so we would recommend starting a Home Log so that you can start to read the house and what has been done to it over time. This makes people's lives easier in the future as well as for you.

This idea is not only for major refurbishments, it is also worth thinking about for smaller jobs. For example, this week I spoke to a lady who had a problem with her shower. A leak from an unknown source is occurring, but she cannot gain access to the underbelly of her shower tray without taking it all apart. This is a major inconvenience and an expense that might not yield the solution. However if there had been a 'trap door' fitted to the ceiling below the shower unit, access would be simple and the problem resolved without the need for a plumber / builder. Simple solutions like this might not be as 'clean' on the eye, but practically what a saving it would have been since it was only a few years ago when a similar problem happened and the builder had to go through the ceiling for access, so rather than a conventional plasterboard finish being applied, a simple trap door would now be saving the customer a lot of time and hassle.

So I think that it is worth while having well labelled (and possibly photographed) service routes that can be accessed easily even if it does mean a little bit of extra record keeping and some non-continuous surfaces.

Thursday, 25 August 2011

Sound proofing in high impact areas

A first request for an answer to a problem. This one comes from a community centre in Cardiff and refers to how to help sound proof a community hall but also to keep a surface that will take the knocks and scrapes associated with playing games etc.

There are a couple of issues here and actually a common solution can be found that will help both.

Sound really comes in two main forms, ambient and impact. Ambient sounds are background mid range noises like talking, general hubbub etc, whilst impact noises are lower frequency and tend to be louder. To reduce sound transmission one requires a variety of material types that will affect different frequencies. Having heavy weight dense materials mixed with lighter weight ones and also ones that have a cushioning affect mean that the different frequencies of sound can all be reduced.

If we look at recording studios for example they use a range of techniques like having a 'floating room' where rubber is placed between structures to absorb sound and so isolate the sound studio. They also use angled glass of differing thicknesses to deflect sound and to reduce sound transmission across a greater range of frequencies. The room is also sealed so that there are no sound leakages, so a constant seal is important. Care is taken to ensure that rooms do not set up their own resonances because of having parallel walls, so walls are made to be angled and have 'rougher' edges as this disperses the sound in a less echo-ey manner.

So when looking at a community centre one can see that it is possible to use an internal system to reduce the noise transmission just by having an internal wall made of different materials with different densities, mass, resonance frequencies and also potentially with varying surfaces / angles.

There are also specialist materials like very heavy rubber sheeting that can be used to provide even more mass in a structure, e.g. acoustiblok.

So a make up that would have dramatic effect on the sound proofing of a wall would be:

Existing wall
Rubber strip attached to a 100mm stud wall frame
Higher density 75mm insulation(there are a range of 'acoustic insulations' available from virtually all the manufacturers)
Acoustiblok sheet (optional)
Heavy weight boards (here we would not recommend plasterboard as it can make sound worse by its resonance), so a product like a 25mm or 50mm woodwool board. These are incredibly strong and can easily take being basked around by footballs etc
Lime plaster / render with an embedded mesh
Silicate paint finish

By having a mix of heavy weight, fluffy and absorbent materials the vast majority of aural frequencies will be radically reduced. Care needs to be taken to ensure that all gaps are sealed up so that leakage is kept to a minimum. All doors and windows will also have to be checked to make sure that they are either double or preferably triple glazed and that there are draught-proof seals in place.

Similar structures can be used in a ceiling, but here there is a additional opportunity to put in different angles and shapes into the structure to reduce the possibility of resonance problems.

So the more mass, the more different types of material and the more deflective the design the better for acoustics.

Wednesday, 24 August 2011

Alternatives to plaster boards

Plaster boards are a sandwich of paper and gypsum that are commonly used as a finishing board for walls and ceilings. They are then skimmed with gypsum / thistle plaster for a really fine finish. The final smooth and flat finish is suitable for a modern home but it can take away from the natural flow and rustic finish in older properties. It can also hide a multitude of sins (see post on dry lining). So we are always keen to stress that plaster boards on walls in older houses should ring serious alarm bells. However they do have a place on ceilings as there is less to hide on ceilings (apart from artex of course). Plasterboards are now also readily recyclable through municipal site, so their eco-credentials are improving. However are there alternatives?

There are a few options:

1. Do not use plasterboard - just use a plaster over the walls, ideally this would be lime or clay plaster dependent on the type, style and requirements of the wall and your preferred finish. Lime plaster or hemp/lime give a breathable finish and allow you to preserve the natural idiosyncrasies of your wall, They also give you improved insulation values. This process takes longer and hence costs more, but potential problematic issues around airtightness and breathability are negated.

2. Use a woodwool board. These are boards that come in various thicknesses that can be plastered directly onto. They are made from wood and a binder (normally magnesium silicates). They have good acoustic properties and have a good key for plasters, however you need to be careful around the joints - these need scrim to stop cracking and some would advocate using a mesh over the whole of the wall / ceiling.

3. Use a woodfibre insulation board. These are finer insulation boards that provide insulation (acoustic and thermal) for internal walls. They are designed to have good compressive strength, but are of course deeper than plasterboards. They can be rendered / plastered directly onto, but again recommended to use mesh.

4. Use laths. For ceilings you can now replace old laths with new ones (from Traditional Technologies). These are pre-constructed panels that are nailed into place and then a lime plaster applied. These do not need scrim or mesh and provide a much more authentic finish than plasterboards in older buildings.

So there are a few options to think about. For more info please contact the Eco Home Centre.

Tuesday, 23 August 2011

Can I get exterior wood looking like new again?

Wood is affected by weathering and UV light. What starts off as a beautiful rich and vivid colour can soon start to grey and lose its initial attractiveness. Some woods can benefit from this as they turn lovely silver hues, however most go dull and look tired.

Furniture, decking, panelling, fencing and wooden pillars all suffer from this unless they have been pre-treated with a UV protector, or an oil with some colourants in. Even then they can start to lose their sheen after a few years unless one is really diligent with the topping up of wood oils.

The best way of restoring the colour and vibrancy to old dulled wood is to use Oxalic Acid. This is a natural product that is found in rhubarb and other plants like sorrell. It is much stronger than acetic acid (3000 times so) and hence is used for cleaning and renewing surfaces.

Osmo's Wood Reviver is effectively an Oxalic Acid solution that is designed to be used easily with wood. By brushing on, leaving and then brushing off again it will clean up your wood and leave it looking as good as new. Once cleaned we would recommend other Osmo products depending on the use of the timber that has been cleaned and refreshed.

Thursday, 18 August 2011

How do I clean off green growth from wood and stone safely?

Cleaning off plant matter from wood and stone surfaces is generally regarded as a pretty toxic occupation. This is because nearly all the products used are in fact pretty toxic. You can do the whole job manually, but most people are looking for a quicker and easier solution than this, however we would recommend doing any cleaning without chemicals if at all possible.

Any treatments have to be able to kill / remove the green growth and thus must have some level of toxicity to plant life, however there are different ways of achieving this. The product that the Eco Home Centre sells is the Osmo Green Gard. This is a biologically degradable and it also does not contain any formaldehyde, nor chlorine or phosphate. It also has a low odour. So despite being a very effective product it does not have the level of potential for environmental harm that most of the other products on the market have.

So in reality there is no real chemical based way of removing green growth quickly and entirely without risk, however risk can be managed and minimised by making the right choices.

Eco cleaning

Sick Building Syndrome (see earlier post) is a recognised problem, especially in internal environments where we spend a lot of our time (work and home). One of the main causes of SBS is the fumes and chemicals that we use for cleaning. We have a fear in the UK of germs and bugs and this has led us to use powerful and toxic chemicals to clean our buildings.

Most of time we do not need surfaces to be 99.9% bacteria (etc.) free. After all we rely on bacteria to live and we have evolved to be able to live alongside the vast majority of bacteria and bugs that live in our homes. It is also worth noting that it does not take very long for surfaces to lose their resistance to bacteria once they have been cleaned, so unless you have OCD it is worth worth relaxing about exterminating bacteria in your home. You will never win after all!

So number one is to reduce the amount of cleaning chemicals that we use in our homes. By using toxic chemicals we are after all putting ourselves at more risk than by having slightly dirtier surfaces.

Many of the chemicals that we use are hazardous in a number of ways:

Risk of accidental ingestion
Risk of spillage onto exposed skin / eyes etc
Inhalation of fumes from the chemicals when in use
Harm to wildlife (especially water life) when disposing of waste water
Increased waste disposal issues associated with containers

Number two is to use more natural products that are not so toxic or damaging. Many cleaners are now available through the likes of Ecover, but there are other more specialised ones like Eco Solutions who do Hand Cleaners and Degreasers. These products still do what you want them to do, but not at the level of risk and harm associated with the more conventional ones.

When it comes to cleaning up before or after DIY there are a few options including the use of Plant Soap to clean walls and other surfaces and Orange Oil as a powerful solvent.

So be kind to yourself, your family and your home by using less damaging cleaning products and look for some more natural alternatives.

Drylining - Hidden Horrors

I really cannot express the amount to which I mistrust Drylining.

I would not recommend anyone to undertake this exercise as it can be a real death nail to any house.

What dry lining does is cover up the problems associated with walls - damp, character and bad workmanship to name a few. So what happens once you have covered over the problems, do they get any better? Of course not. In fact they often get worse. I hope that I am getting the message across here!

Dry lining is most commonly used in older homes to cover over damp, so rather than cure the problem we leave the house damp, colder and more prone to structural damage. The damp walls allow mould and fungi to breed and also make the house colder as the water in the walls conducts heat that much more than a dry wall. So you will have higher heating bills, poorer internal air quality and no real way of knowing whether it is getting worse.

If you are buying a new house then it is worth tapping the walls to see if it is dry lined. If it is, I am almost tempted to say walk away or at least look to haggle down the asking price to give you a workable budget to remove it and sort out what ever problem caused the previous owners to dry line it in the first place. Have a good look at the outside walls and guttering, you may be looking at having to re-render the walls (in lime render of course) and replace the rainwater system.

Insulating plaster boards are also effectively dry lining, so again this might ring alarm bells especially in ground floor rooms. Upper floors are less susceptible to the horrors than can afflict ground floors (less likelihood of rising damp for example) but be aware of wind driven water ingress from cracked render and painted walls.

If you are tempted to install dry lining, please don't. Sort out the cause of the problem with the walls rather than covering it all up, you are doing everyone and the house a favour in the long term.

Wednesday, 17 August 2011

Sick building syndrome. What to avoid.

The World Health Organisation recognise Sick Building Syndrome as a real issue and have written a number of reports on it. With the interiors of buildings being in the news of late I thought that it was worth throwing a bit of extra light on the topic.

Most buildings are not designed for people. They are designed for profit, efficiency and style. Many buildings look great, but are in fact really awful to work or live in. So what causes this?

There have been a range of factors noted that can adversely affect the health and well being of people using / inhabiting buildings. I shall go through a few here and give some potential solutions to them:

Lack of natural light - we rely greatly on artificial light and this does not have the full spectrum that we get from the sun and so it is not what we need as humans. More natural light in buildings is essential for conditions like Seasonally Adjusted Disorder (SAD).
Solution: Increase the amount of natural light using things like sun-pipes, increased size of windows, fit LED lights rather than conventional energy saving bulbs (these have a higher colour rendering index) especially in areas where people are doing detailed work

Chemical Off gasing - many products like MDF, Foam, PVC, Paint and cleaning products give off invisible gases. Many for all of their life. This haze of chemicals (some of which are known toxins) are breathed in and then reside in our bodies as we have no natural way of processing them. This build up of artificial chemicals can lead to a range of health problems.
Solution: Use natural products like eco-paints, untreated wood, latex foam, natural cleaning products. Also have a lot of plants in rooms as these will absorb some of the pollutants

Electro Magnetic Fields (EMF) - in areas using lots of electrical equipment the wires set up a series of EMFs. No one knows for sure how this affects us (just like the effects of using mobile phones is debated) however it is noticeable that houses are no longer built under pylons. Having a large amount of EMFs in our immediate environment can therefore be an issue for some.
Solution: House electrical wiring in EMF protected conduits

Ventilation - There is often a lack of sufficient ventilation in buildings and this can exacerbate the issues with off-gassing as well as encouraging the formation of mould, spread viruses etc. So having a well ventilated space with fresh air is important. However one must bear in mind the need for energy efficiency especially in the winter months.
Solution: Build using breathable materials / structures to help to regulate relative humidity levels and also ventilate using heat recovery systems to minimise wastage of heat.

Views - Having a good view can be important, but it is also important to be able to focus on items that are far away. With much of our work based in front of computers it is necessary to give our eyes a break from close focusing, so having some interesting / pleasant things to look at in the room can help alleviate eye strain.
Solution: Give people views or at least something to focus on that will encourage people to look away from their screens every few minutes.

Social space - As social creatures we need to have interaction with others and so the 'water cooler' or staff area is important. Similarly we need differentiation at home. One room bedsits are not conducive to happy living as it combines social with private space and this is not what most people need or want.
Solution: Ensure that there are distinct areas of private and social space in the layout of buildings

Access to nature - having a garden or access to outdoor space is important to many people. It connects us to nature and provides a sense of place and grounded-ness for many.
Solution: Provide gardens or green space for people, even if this means importing plants into the internal space.

Large temperature swings - Having high internal temperatures changes is also sited by WHO as an issue. Whilst insulation has improved in buildings over time there is still a way to go, especially in certain environments like lightweight timber constructions.
Solution: Use insulations that have a high decrement value (this can delay the maximum temperatures from reaching the internal environment to such an extent that it becomes non-problematic).

Tuesday, 16 August 2011

Thinking about underfloor heating? What are the pros and cons?

Underfloor heating has a range of advantages, some of which are obvious, others less so. It can also be powered by two main sources of energy - electric or hot water.

We shall focus on the hot water systems here becauseI am not a fan of electric heating unless you are able to supply it with renewably sourced current. It also tends to be a retro-fit solution that comes in tile or webbing format. These require insulation underneath but this is not commonly added in sufficient quantities to make it efficient. However if you are desperate for underfloor heating and the added value that it brings to the house and are only looking at small isolated areas then it does become the only viable option.

So to the advantages of underfloor heating with hot water

Freed up wall space
Rather than having radiators cluttering up your walls underfloor heating removes the need for visible and space consuming pipework and rads. This is a great way of creating clean lines through out the the house and minimising dusting.

Warmth where you want it
Our feet are the most psychologically sensitive parts of our bodies to heat. So if our feet feel warm, we feel warm. This means that you can effectively run the system at a lower ambient temperature if needed.

Less risk of damage
Earthquakes aside, underfloor heating is really protected from damage. The chances of being knocked around, leaks etc are much reduced by having the pipes encased in concrete (or similar).

Even heating.
Assuming that the system has been designed correctly, you get as much more even spread of heat in the home by using underfloor heating. Getting the zones and circuits right though does require some knowledge but most companies will do the design for you.

Use of low heat energy sources.
This is growing in importance for water based systems. Some heat sources (Ground and Air Source Heat Pumps most notably) are only good at producing low temperature water. Underfloor heating requires low temperatures rather than hot ones and so they tie in really well with these emerging heat technologies.

The new manifolds have excellent controls for managing different areas of the house independently, so it is easy to get the heat where you want it.

So what about the Cons?

The main ones are around quality of pipes, insulation, design and installation.

Because the system should be fit and forget it is best to use high quality pipes that are free from any underground joins.

The floor must be well insulated and this means that it needs to be insulated under the slab and also at the edges. We would recommend at least 100mm underneath and 50mm at the perimeter.

The design of the system is key as they can operate at different temperatures, so you need to ensure that the heat source is closely matched to the requirements of the heatings layout. The plans are also key to ensure that you have have more pipes around the edges of the room and less in the middle. Some people just fit the same all over the floor rather than having two different levels of pipe concentrations (normally you have pipes half the distance apart on the perimeter).

It is also worth noting that many people run underfloor on the ground floor but not on the upper floors. This can lead to problems with the heat source as radiators want to run at higher temperatures. However, if you are happy to have cooler upstairs then you can run slightly oversized radiators at the lower temperature to obtain a cooler upstairs environment. If you want the same / similar temperatures then you will either need: oversized radiators (and this negates the some of advantages of clean lines etc downstairs); or to run underfloor heating upstairs as well (this is possible); or to have higher temperatures available to conventionally sized radiators. There are solutions to all these scenarios, so for more advice please call the Eco Home Centre.

Installation is important as you must have continuous piping for each circuit (no joins) and the system installed to manufacturers requirements. There are different systems (quick response non screed and the slower in-screed systems) and so you want people who are au fait with these different to ensure that they are installed correctly. The whole system also needs to be fully pressurised and tested before screeding / covering.

So overall, we highly recommend using underfloor heating both in new build and retrofit, but you need to be aware of the potential shortcomings to ensure that you do not suffer from them.

Do decorating fumes and smells get you down?

Conventional paints, glues and some materials all have a little secret and it involves smells and other invisible fumes. As paint and glue dry they go through a chemical process where monomers combine to create polymers. This can be visualised as short pieces of string combining with others to create long pieces. These polymers give the paint its finish and strength, however what happens to the monomers that cannot find a partner? Well they are gassed off along with the evaporation of the solvents that are used.

So when painting there is a haze of chemicals being released into the atmosphere of the home. These are collectively known as Volatile Organic Compounds (VOCs). These compounds are associated with a range of health problems including headaches, nausea, asthma to name a few. No wonder that Painters and Decorators, as a profession, have one of the highest incidences of breathing related illnesses.

The worst of the paints are those that have the highest VOC rating. The VOC rating is closely associated with the levels of oil content. Natural paints though can contain oil, but they are natural oils, ones that our bodies and the environment are already used to. So for example, by squeezing an orange we give off VOCs but the environment can process these chemicals and hence they do not pose any real risk to us. However, most conventional paints use man-made chemicals that are alien to the environment and our bodies and so we cannot cope with them as well.

So do not be fooled by VOC ratings on paint. VOC is an umbrella term that encompasses a wide range of chemicals and their effects vary. Always go for the natural products as these will have a much lower long term impact on health.

Some products like foam, pvc and mdf (basically those materials that have synthetic glues, blowing agents in them or that degrade over time) can also off-gas chemicals into the internal environment. So for example MDF and chipboards off-gases formaldehyde, polyurethane foams (found in mattresses, sofas etc.) off-gas isocyanate for at least 6 months, PVC is high in toxins and dioxins, such as lead, cadmium and phthalates (linked to DNA damage) and mineral and glass fibre insulation may be carcinogenic due to their effect if breathed in.

Worst of all is that these chemicals stay in the home environment specially where we have well draught proofed houses. So best to avoid these materials and just use natural products. Also you can get zero VOC paints from companies like earthborn. These amazingly include eggshell paint in the form of ProAqua Eggshell.

To help reduce internal chemicals building up why not grow some spider plants as they are excellent absorbers of airborne pollutants.

Rewiring tips

Many older homes are upgraded by a re-wire. This ensures that older electrical wiring is up to modern standards and hence should be safer. This is an expensive process where not only wires, but sockets and switches are also changed. It involves a lot of 'chasing out' of plasterwork, drilling through joists and rafters and general disruption. Therefore in our opinion it is worth looking at doing the job properly and as few times as possible.

So there are longer term advantages to ensuring that your newly rewired house is up to the task for the next 20 - 30 years. So we would encourage people to think about the following:

If you have a south facing roof, you may be tempted at a later date to put in a photovoltaic (PV) system or a solar thermal one. These require electrical feeds / wiring to work (either to run pumps or to take the generated electricity into your home / the wider grid). So whilst having work done why not allow for two additional wires to go up into the loft space. Each system will also require its own circuit so allow for two circuits when planning / specifying your consumer unit. Note that a PV system will also require a Generation Meter as well, so this will require approx. 150mm by 100mm of space next to the consumer unit as well.

You might also want to allow for changing showers over to electric (as the grid becomes more de-carbonised). This again can be installed and left coiled up ready for use at a later date.

The house might also be extended at a certain date, so again allowing for more circuits (lighting, ring main, shower etc.) is a good idea, as is getting the cabling to where it can be accessed at a convenient time.

Allowing for enough sockets is a common fault in re-wiring. As we use more electrical devices the pressure grows on sockets, so again allow for plenty of these.

You might also want to think about locations of sockets. Having sockets at a higher location on the wall makes them easier to use when we get older, so again think about this.

If you are looking to stay in the house for a long period of time or to retire into then it might be worth thinking about circuits for stairlifts etc. These circuits do not need to be active, but they will reduce stress, disruption and hassle at a later date if the equipment is needed.

With having walls chased out for circuits you might also want to think about putting in conduits for communication links. Again these can be left with draw strings on, or with cabling in situ running to each room.

The last but one suggestion is that you think about a central service area where all the cabling etc can be installed and spurred off from so that you know where all your cabling is in the future and how to access it. Removable floorings / ceilings can assist with maintenance / access as well.

And lastly, we would recommend having a schematic / photos / maps of where all the cabling runs. This will make future occupants (as well as yourself) more aware of where all the cabling is, especially if you have installed additional future-proofing circuits.

Can I refurbish old paint brushes?

Many people have a stack of old dried up paintbrushes stuck in assorted drawers, jars and cupboards. These are generally only found when the next decorating job comes around. These rock hard brushes are then discarded and the process started again. This means of course lots of waste, expense and a reliance on cheap brushes that shed their bristles in your lovely new paintwork.

So is there an answer to this perennial problem?

Eco Solutions make a Brush Restorer. Basically it is a clever way of removing paint from old brushes overnight. Just leave the hardened brushes in the solution and then once it has softened the old paint you can wash it all out to make your brushes (almost) as good as new.

By having a system of being able to clean brushes, even if you do accidentally forget to clean them every now and then, it allows you to buy some better quality paintbrushes that will not shed their bristles with the same generosity as the cheaper brushes and also provide you with a better quality finish to your handiwork.

Is it possible to make a DIY green roof?

There are now DIY kits for green roofs. These can be reasonable value for a fixed area of green roof - normally 9 sq m per pack. But there are a range of issues that need to be addressed before getting too carried away:

Type of green roof - there are a wide range of options here from using extensive systems (the more common sedum roofs) to intensive ones (turf roofs that can support a wider range of larger plants). The extensive ones are much easier to install, but harbour less wild life.

Weight - green roofs vary between types, but the extensive sedum roofs are by far the lightest ones. This is important as they joists / rafters in your roof will not have been designed to take the extra weight of the green roof and so you will probably need a structural engineer to sign off any designs (if you want to have an 'official' green roof. Remember it is not just the weight of the materials, it is the weight of the water retained within the structure as well. With water weighing 1 tonne per cubic metre this can add significantly to the load requirements of your roof.

Objective of the green roof. Is it there to look nice, to slow down water run-off, to help cool the urban environment etc. For slowing rainwater run-off significantly you need to have a larger, deeper and heavier roof, so this affects weight.

Aspect of the roof. Is the roof heavily exposed (south or west facing), it is overshaded? This will effect the type of planting that will survive on the roof and hence needs to be explored.

Slope of roof. Green roofs can be applied to quite steep roofs. Up to 30 degrees can be achieved, but you do need retaining bars in the roof to stop slippage. So this requires more thought and infrastructure to get it to work properly.

State of existing roof. All green roofs need to go over working watertight roofs. It is not a sticky plaster. So many people find that they need to replace their existing roof anyway before embarking on a green roof.

Overhanging fauna. If you have a range of larger fauna (trees, shrubs etc) overhanging the roof then seeds are likely to be deposited and hence take hold. Even though green roofs are designed to only support certain sizes of plants this does not stop the seeds from germinating and forming seedlings. The draft plants that this produces might well need weeding out, so this gets onto:

Access to the roof. Green roofs are not fit and forget. They do need some maintenance even if well planned. So you will need to allow for this and for the additional weight associated with standing on the roof.

Style of the roof. Most green roofs have a range of system edges. Where water enters the roof (run-off from other roofs / gutters etc.) you need to have a buffer to slow the water's speed so that it does not wash away the plants. Also the edges of green roofs are generally outlined by river pebbles. These stop / slow the plants from growing over and into the guttering and potentially causing problems with the rainwater. So you need to think about what it is going to look like and how you are to retain the green roof / pebbles.

Green roof systems are therefore more complicated than just going out and getting a kit. However, there are major advantages of having green roofs especially in the urban environment and so as long as they are well thought out and planned they can extend the life of your roof considerably and also bring fauna, flora and cooling to our towns and cities.

Are there more eco-friendly plasters than Gypsum?

Gypsum plasterboards are a quick and cheap way of covering up walls. Combined with a skim of gypsum plaster this is the predominate way of getting a smooth finish on internal walls in the UK.

Gypsum is a common mineral and the boards are fairly energy efficient to produce (only requiring a temperature of 150 degrees centigrade), however they are damaged by water and also support mould growth. So you have to be careful where the boards and plaster are used. In high humidity / damp rooms (bathrooms and kitchens) it is recommended that other boards are used. However by using these water resistant boards one effectively seals up the room and you then have to rely on mechanical extract to remove the warm humid air.

Gypsum therefore suffers a bit from its hygroscopic nature (attractiveness to water) as it will eventually fail and disintegrate from the water absorbed into its structure. By retaining dampness it also encourages mould growth. So whilst gypsum might be an OK plaster (it does give a very fine finish) for more modern buildings when applied in the right areas, it is not an universal product for all building types and locations.

Where breathable solutions are required (in older solid walled homes) the original plasters used were lime based. These naturally inhibit mould growth as they are more alkaline and they are also breathable rather than hygroscopic. So water vapour can pass through them without effecting their inherent structure.

So when choosing plasters it is worth considering the alternatives:

1. Lime putty plaster
2. Clay plaster
3. Cement (hydraulic lime) plaster
4. Insulating plaster

1. Lime putty plaster
This is the type of plaster used in the older houses. It is a more course finish in the main as it uses aggregates to bind the structure together. However to get a fine finish it is possible to use a final coat of pure lime putty. These plasters are highly breathable and allow excess moisture into the wall structure when required and then release it as internal relative humidity drops. In other words they can act as humidity regulators in the home. This can be seen when using clay paints as a final painted finish. The clay paint darkens as the humidity increases and then lightens as it dries out again. So lime plasters are ideal for old solid walled homes where the breathable nature of the walls is intact.

2. Clay plaster
Clay plasters can only be used a skim coat. They are ideal for going over lime renders / plasters to give a very fine finish. There has historically been an issue with dusting from these plasters as they have no binders in them. Effectively they are dried clay on your walls. However, new innovations have meant that now you can create a non-dusting finish. By using clay you have a plaster that can be dug out of the ground and applied directly to your walls - now that is really low carbon!

3. Cement (hydraulic lime) plaster
These plasters are designed to be more robust and hence are less breathable. They are good where you want a quick set, a harder wearing plaster and one that is getting towards waterproof. These plasters vary in strength depending on the lime / cement used. NHL Lime 2 will give a softer and more breathable finish than a 3.5, which in turn is more breathable than a NHL 5 and so on up to cement. They need an aggregate to work and so the finish is determined by the size of grain in the aggregate.

4. Insulating plaster

The new breed of modern insulating plasters say that you can get a fine finish on them, however having tried them out it would take a lot of effort to achieve this. So they are good as renders, but would require a skim over the top. They are also breathable and so can take a clay or lime plaster to give the final top coat. Obviously these are great in areas where you are removing renders and plasters and you want to achieve an insulating result on an external or party wall.

Overall your choice in plaster will be driven by a range of factors, however we would recommend using lime and clay plasters if you are refurbishing an old solid walled building, or you want to create an eco-build.

Wednesday, 10 August 2011

Timber. Is it all sustainably sourced?

One of the key factors that the construction industry has embraced has been the sustainable sourcing of timber. The prevalence of 'Chain of Custody' marks like the Forest Stewardship Council (FSC) and the Programme for the Endorsement of Forestry Certification schemes (PEFC) allows people to trace back timbers through the supply chain to sustainable forest enterprises.

Many people are aware of such schemes and certainly the larger players all stipulate FSC / PEFC timbers on their construction projects. Larger supply companies like Travis Perkins, Jewson etc also promote the marks and many state that all of their wood comes from these sources. Go all good news, but is it?

When we talked to Travis Perkins the front of house notice was that 100% of wood was sustainably sourced, however we asked for a print out of stock and on this we found that whilst the majority was FSC or PEFC marked there were several product ranges that were not. These are primarily ply woods where exotic hard woods make up a proportion of the timber. So don't be fooled into believing that 100% of stocks is from sustainable sources. Ask the office staff who deal with procurement / stocks about the certification of each of the products that you are interested in. You may find that the 12mm Ply is FSC but the 15mm is not.

Buying non-sustainable forestry marked woods is often linked to illegal or clearance type logging and this is rapidly destroying forests across the world, especially in tropical regions.

If you are desperate for tropical hardwoods rather than European ones then you can look for specialist suppliers of FSC timbers.

Can I get graffiti off of my walls safely?

This may or may not be topical what with the troubles affecting the UK at the moment.

Graffiti can blight neighbourhoods with offensive words, images and negativity and so its removal is important for social cohesion as it can diminish atmospheres of fear and mistrust. Having said that it does have its place in the social fabric when it is done in artistic and peaceful contexts. We would not have a Banksy without the media after all.

So if looking to remove graffiti one would assume that it would require some fairly corrosive and chemically non environmentally friendly potion. In the mainstream this is in fact the case. Professional cleaners (with all the appropriate Personal Protective Equipment - PPE) might come in and clean up unwanted marks, but this is an expensive way of doing things and can take weeks / months for it to happen. So what we need is a solution that individuals / groups can have access to that will allow the community to clean itself up.

Thankfully Eco Solutions have a product called Graffiti Go! This is a simple to use spray that allows ordinary people to roll up their sleeves and clean up walls, windows, wood etc from graffiti without the need for all the PPE that the professionals use. Graffiti Go! is safe to use and is also environmentally sensitive. So it is safe around schools, youth clubs etc and can even be used by the perpetrators to clean up their own mess!

Note that it will remove all paint, So if there is graffiti on a painted surface then all the paint will come off, not just the graffiti.

Graffiti Go! is used by lots of Graffiti Buster teams across the UK because of its safety features and its effectiveness.

Saturday, 6 August 2011

Are ground source heat pumps any good?

Not so long ago Ground Source Heat Pumps, (GSHP) and their more urban cousin the Air Source Heat Pump (ASHP) were being touted as part of the answer to carbon reductions in the heating of houses. All boast something called the Co-Efficient of Performance (CoP). This is a equation that states the change in kWh between the energy consumed and the energy produced. So typically for every 1 kWh of electrical energy (needed to power the GSHP / ASHP) the system can theoretically produce between 3 and 4 kWh of heat energy. This sounds great. Surely this is 'free' energy.

Well, yes and no.

Yes. The fact that the systems use latent heat in the ground or air to extract heat for use in the home is great. This is especially the case if you are using electricity from renewable sources (mainly this means wind and hydro power as solar is not so plentiful when powering your heating system in the winter). As our mains electricity production changes over to ever more renewable sources of energy this bodes well. The system also produces its best CoP when producing lower temperature water, so it is ideal for underfloor heating or oversized / specialist radiators systems.

No. Most people are using mains electricity to power their GSHP and this is seen as being about 30% efficient, so the CoP of around 3.5 only changes the mains power back to its source fuels original potential. I.e. Gas burned in power stations has a potential of 100%, the power station's processes and national grid's network reduces this to around 30% of its original potential and then the GSHP changes this back to 100%. Would it not be better to have used the oil / gas etc in the home? Arguments can rage here around figures etc, but the overall principle is true at the moment.

There are some more problems as well that you will need to be aware of:

GHSP / ASHP are great for the lower temperature systems, but you need to have one, so ideally you will need to budget for changing over to an underfloor / oversized radiator system.

This lower temperature also means that if it is driving your Domestic Hot Water (DHW) as well it will need to reach 60 degrees once during the day to combat any chances of Legionnaires Disease. For this an immersion heater is generally used. So it is not a great energy saving system for your DHW. Linking in with a solar system will help during the summer months etc.

A recent Energy Saving Trust report looked at a wide number of GSHP and ASHP data to see how they were doing. The reading was not good. Most systems in the UK were operating at around 2.5 CoP, so well down on what was being touted by suppliers. This has been put down to the infancy of the technology in the UK. However these same products are working at around 3.5 CoP on the continent, so why not here?

The answer seems to be that in order to save costs systems are being installed by different teams of people. Some designing the system, others digging the trenches, others installing the systems, another company doing the underfloor heating etc. What is being recommended is that one company does the lot. There is then no dispute if it doesn't work properly and also they will have control over things like: Original calculations on the size of the system? How long are the underground pipes?; how deep are they?; what underfloor heating system is being used?; how are the controls set? There is no reason why the UK installed systems are not as efficient as the European ones.

In conclusion, where you have no mains gas and your oil bills are soaring (bear in mind that electricity prices are also going up!) you may wish to look at a GSHP / ASHP. With the greening of the grid slowly under way the present day high carbon associated with electricity will slowly drop and the electricity powered heating systems will become more sustainable. However, you will need to remember to look for a low heat delivery system and also reduce your demand by insulating your home as much as possible. You will also need to think about your DHW and how to get this up to temperature without breaking the bank. Also look at how you commission your system. Try to stick to a reputable company who can take control over the whole process and give a meaningful guarantee. Also, monitor your consumption to make sure that it is all working properly. Switch your electricity supplier to a Green Tariff so that you get extra piece of mind.

GSHP and ASHP all have a place in the mix to reduce carbon but they need to be designed, installed and commissioned well. All also need to think about minimising demand and maximising the capacity for low heat delivery.

Friday, 5 August 2011

How to choose a builder

This is a key factor in doing work to ones home. We look for various things in a builder:

Recommendations from others
Skills / competence

What we don't look for is any underpinning knowledge of buildings.

Unfortunately builders are not trained to understand building types, they are trained in skills. So a competent builder probably has no idea that old terraced houses need to have different materials used on them compared to more modern building types. This is a major problem that it only just starting to be addressed by the colleges, even then it is not well co-ordinated or taught.

So the vast majority of builders do not understand the importance of concepts like airtightness, breathability, water and energy efficiency? If they don't understand or place any weight on these factors then the quality and suitability of the work will suffer. So if you want a; draughty, energy inefficient or damp, piece of building work then fine, go with the cheapest. However, if you want a home that is airtight, dry, low maintenance, energy and water efficient then you need to find a knowledgeable and competent builder.

Asking builders some open questions (that you know the answer to) is a great way of identifying whether they can fulfil the tasks that you want of them. Don't ask Yes / No questions as they might be able to guess which answer you are looking for. So questions lie:

What do they understand by the term breathability and how this relates to the different types of lime or cement?
How will you achieve good sound insulation?
Will this product save me money and inconvenience in the future?
How will you ensure that the building is airtight?
Is this the most appropriate insulating material for my property and why?

(For the answers have a read of the other posts in this blog!)

Getting the right builder is so important. None are cheap and the cheapest often turn out to be the most expensive as you spend the time and money on the next builder trying to solve the faults from the first one. So it is a bit like finding a good relationship were they are able and willing to do the work and you are happy to trust them (within reason) to do it right. Remember that many builders use sub-contractors (their mates) to do parts of the work - electrics, plumbing, carpentry etc and so these people must also be 'on-board' with what you are trying to achieve. So communicating well with the builder is so important, as they will need to be reminded that their colleagues will also need to understanding what is happening, what you are trying to achieve and what they must do in order to facilitate this rather than wreck it. This is so important in areas like breathability and airtightness. No point using lime renders and plasters if the Painter and Decorator covers it all with plastic paints! Again no point installing great airtight membranes if the Plumber drills through them to fit an outlet etc.

Don't blame the builders though. Remember they were not taught about sustainability in college, so you might wish to send them to the Eco Home Centre for some additional awareness raising before starting with them. This is so important for older buildings or high performance ones.

There are starting to be some safeguards though. The Federation of Master Builders (FMB) has a register of MasterBond builders. These are not schooled in sustainable practices, but they can offer a guarantee for their work.

At the Eco Home Centre we are also building up a base of builders who do understand older and high tech buildings and how to install the right products for the house, so if you are stumped to find a reliable, intelligent and knowledgeable builder please do get in touch and we shall endeavour to find you one from our database. Contact via:

Thursday, 4 August 2011

Can I make my boiler any more efficient?

Boilers have been replaced at a amazing rate over the past few years. Registered Social Landlords have a responsibility to ensure that their stock have energy efficient boilers and the Government recently had an incentive scheme for replacing the really poorly performing boilers. So is there anything else that we can do?

Well there are some key options for people to bear in mind when thinking about trying to improve the efficiency of their boilers, even if it is an A rated boiler.

1. Install Weather Compensation onto your boiler. Many new boilers are equipped with a option for Weather Compensation but few are installed. Basically this is a thermometer on the outside of the house that lets the boiler know what the temperature is and then make automatic compensation for this. So if it is a warmer day outside then you need less heat in your home and vice versa. These systems are estimated to make your boiler 10% more efficient.

2. Install a PFGHRD - Passive Flue Gas Heat Recovery Device. These are systems that take the heat from the exhaust air and use it to preheat water. These work really well in the winter months when you are using your heating system. The domestic hot water is preheated using the exhaust gases and this means that less energy is needed to heat the water and also that it heats up quicker, thus also saving water. These systems can give some significant savings on the heat load of the domestic hot water. It is estimated that they can match the amount of heat saved by a solar thermal system.

Can changing radiators make my home more comfortable?

The delivery of heat from our boilers to the house is often an overlooked area of importance. There are a number of factors that influence choice of radiators:

1. Temperature range being produced by the heating system
2. Design of the radiators
3. Radiator covers
4. Size of the radiators
5. Use of Thermostatic Radiator Valves
6. Location of radiators
7. Insulation of heating system

1. If you have a low temperature system (like Air Source Heat Pump, GSHP etc) then you need to get 'oversized' radiators so that it can deliver the lower heat and still reach the internal temperatures desired.

2. The design of the radiator has a large impact on how effective it is in delivering heat. Modern radiators have more 'fins' that radiate the heat better. Fancy designs of radiators might have a large effect on their effectiveness.

3. Placing radiator covers over your radiators reduces the amount of heat that each one can give out. They can reduce the airflow around them and this can slow their effectiveness.

4. The size of the radiators has an obvious effect and this could be achieved by having double radiators rather than having a larger spatial area of wall dedicated to the heating system. But the size needs to be calculated against the volume of the room and the type of construction of the building. So poorly performing structures need larger radiators and larger rooms need more heated surface area. Your plumber can calculate this.

5. TRVs are a great way of getting the right temperature in each room. By having controls on each radiator it allows you to set the temperature of each of the rooms. So lower temperatures in bedrooms etc.

6. The location of radiators can also have a large effect. Placing one on an external wall increases the amount of heat lost to the wall, whereas fitting to an internal wall means that the wall acts as a thermal store and will release the heat into the room as well as absorbing it when the heating is on. Many radiators are placed under windows to reduce the incidence of condensation. This can be really advantageous if condensation is likely, but it does reduce the effectiveness of the radiators in delivering heat into the room. Also you may need to locate radiators in certain places due to a number of factors -  room layout, furniture, location of secondary heat source (e.g. fireplace). So again ask advice from your plumber as to the best location for each room.

7. You may be in the situation where it is worth insulating the pipework between the radiators, but for most people this is not so important as the heat will be kept in the 'thermal envelope' of the house.

Recently we replaced all of our radiators (along with our heating system) and it made a huge difference. This was primarily due to three reasons.

A. Having the correct sized radiators fitted for each room
B. Fitting TRVs on all radiators (this also provides us with an automatic system that removes the need for a central thermostat)
C. Installing modern finned radiators that give off heat much more effectively.

So remember that it is worth having a good plumber and asking to see their workings out (calculations for radiator size etc.).

Radiator paint - A natural alternative?

One of the issues of using oil based paints in hot surfaces is that they tend to be less stable. White paint will yellow quicker and some will crack / fail. So choosing a specialised paint rather than a common gloss / eggshell is a good idea.

All loose paint needs to be removed before applying a new coat and a 'key' is required in order to allow the new paint to cling onto the surface. But is there a natural paint option?

Thankfully Yes. Auro have developed a thermally stable radiator paint that is water based, natural and easy to use. It can be tinted to give a more stable colour than white if needed, but the actual paint is really good quality and will last years.

How can I remove artex?

Artex was a very common decorating material several years ago with its spirling, swirling and stippled designs still adoring houses across the land. It was used extensively on ceilings and walls, mainly to hide rough patches of plaster, damp and any multitude of past decorating sins. Up until 1984 Artex had a small amount (3-5%) of asbestos in. Anything used past this date is asbestos free.

The main problem with artex removal (assuming that you can overlook the designs chosen by the houses' previous owners) is this asbestos risk (although it is classified as a low risk). This means that you cannot sand off the artex as the asbestos fibres will be released. So you need to do one of two things:

1. Plaster over the top
2. Remove using non abrasive techniques

Plastering over the top is generally seen as the easiest, but it does not remove the artex. This can be done by using plaster boards or by applying a new skim over the top. Skimming though can be difficult, especially with more textured patterns. So generally be prepared to plasterboard and then skim over the top.

2. Removing the artex can be a good option, but on ceilings this becomes more difficult as they artex remover has to scraped off once it has softened the artex. Removing artex from walls is certainly easier using this technique.

Artex removal is probably best done using the Eco Solutions X-Tex product. This is very low VOC, safe and easy to apply, so a real DIY product.

If in doubt, you should be very careful with the artex and consult with a specialist (or have the artex sent for analysis).

Tuesday, 2 August 2011

Does insulating paint work?

There are a variety of claims made about Insulating Paint. When you read the labels there is 'scientific' proof that it can save you 'up to 25%' on your heating needs. Now this obviously has to have a grain of truth in it to get past advertising standards, but there are a range of conditions and assumptions built in to these types of calculations that have no meaningful place in the real world.

At the Eco Home Centre we have an unwritten policy of trying out as many products as we can on our own homes. This allows us to give good advice on how well things work and to tease out any important nuggets of information that might be relevant to customers. Using the Insulating Paint Additive has been a case in point.

What we have found is that there are certain instances with homes where one has little choice as to what to do. When you have no room to install either internal or external insulation on a wall that is cold and suffering from condensation issues, what to do? So we used the insulating paint additive. This was added to our natural paints and tried out. What we found was as follows:

It does not affect the breathability of the paint that you are using, so clay and natural paints still can breathe
It does not give the level of insulation claimed on the bottles, however it does keep the surface of the wall warmer. Just by placing your hand on the wall after application (and drying) you can tell that the surface is warmer.
By having a warmer surface the amount of condensation was reduced and hence the problems with the mould did diminish significantly.
The finish though was also affected. The paint was courser / rougher. This might be fine for some situations, but it can lead to a wall being more difficult to clean. However, by applying another coat of paint (without the insulating paint additive in) the finish was back to normal.

So we would recommend using the paint in a domestic situation where you cannot use real insulation, but where the surface needs some assistance in combating condensation issues.

Where to use Chalk Paint

Chalk Paint from Auro is a really economical way of producing an off-white and highly breathable finish to walls and ceilings. However, there is a catch. Whilst being almost half the price of clay paint it does not have the vinegar esters of the clay. This effectively means that it will not have the binding characteristics of the clay. Whilst it will not rub off on clothing etc it will not have the inherent strength of clay paint.

However given that it is highly breathable and non-toxic it is ideal for areas where you get high humidity and low abrasion to the walls. Cellars, ceilings, store rooms etc are all ideal candidates for its application.

Like all natural paints, the chalk paint can be tinted using natural pigments (earthborn and Auro both do these). So you can have a brighter and more colourful finish if you so wish.

Note that, like claypaint, it does have a translucent quality when applied, but this will turn opaque on drying, so be aware that you do not need to 'trowel' it on to try to get an opaque look when you are actually painting. It is also thinner than a clay paint and so works more like a lime wash, so be prepared to apply 2 or possibly even 3 coats.

Auro Chalk Paint is available from the Eco Home Centre.