Maintenance Matters

Rhyd-y-car Terrace in St Fagans Museum of Welsh Life

For those, who have not been to St Fagans in Cardiff, it is worth the trip. Great place and an ideal way to start to understand how buildings have changed over time.

One of the key elements of the museum is Rhyd-y-car Terrace. It illustrates how one style of property (in this case a Welsh terrace of houses) has been altered over time to address the cultural needs / desires / aspirations of the residents. (click on the photo for a link to discover more)

The original terrace house is represented by the home on the left and the team has made alterations to each subsequent house to reflect the changes to terraces in Wales. So when you reach the last house it has a covering of render on the walls rather than limewash, tiles on the roof rather than slates, modern casement windows rather than sash, large window panes rather than small etc. The internal layouts and services have also changed. Fascinating, but intuitively we sort of know this. However, what is not really explained on site is whether these changes were positive or not.

Of course, we do not want to live in houses anymore that have open coal fires, draughty doors and windows etc. However, neither do we want to live in houses that suffer from trapped moisture in the walls, rotting timbers and poor internal air quality. Unfortunately, some of the 'improvements' that are illustrated in the terrace have caused problems like this in the real world.

In time you could add another cottage to this terrace, with its original stone walls now clad in polystyrene (EPS) external wall insulation. This is a reflection on where we are blindly heading without due regard for the original structure. Again we shall then have a warmer property that is at high risk of overheating and likely to suffer rot and mould issues from penetrative damp and condensation.

Designing improvements to buildings is important, but we must get it right. So again, I urge you to read the STBA documents and guidance on retrofit of older houses. See www.stbauk.org

However, this article is about maintenance. So where does this fit in with the retrofit agenda?

Well, when you read all the underpinning documents about retrofit, they all say that any building should be in a good state of repair and stable before any work starts. So before even contemplating any improvements the house should be damp free and well maintained.

This is where much of the trouble has started. Organisations like the Government have targeted their initial efforts on those properties that were in urgent need and these tend to be the ones in a poor state of repair. So they started putting a load of retrofit measures on properties that weren't ready for it. Putting a load of non-breathable cladding / insulation over a wet wall, just seals in the damp. This would be bad enough, but putting a load of non-breathable cladding / insulation over a wet wall badly so that more water can get in, well, you can guess what has been happening!

So, we need to ensure that our buildings are in a good state of repair first and then we need to ensure that we do any retrofit works well. The second element is starting to be addressed (slowly and still with little real knowledge of the characteristics and pathology of traditionally built houses), but the issues of maintenance is less attractive to business.

Large companies delivering large scale projects are not really interested in minor works, or leaving buildings to become stable over time before starting with the big tools and toys. They just need to crack on, come rain or shine, cold or heat and get the job done ASAP and as cheaply as possible.

So we need to take a step back. Assess what we have, understand it, fix it, let it settle and become stable and then start to improve it sensitively and with the right amount of care and caution so that we don't mess it up.

So the first rung on this retrofit / improvement ladder for traditional buildings is not EPS wall insulation, it is Maintenance and Building Pathology.

CADW have produced some guidance on maintenance, but people see this as being for conservation areas and heritage buildings. We need to make maintenance relevant to the 34% of buildings in Wales that are traditionally built. This means all the terraces and stone / solid brick built homes that litter the landscape that we are so familiar with and proud of. After all it is these buildings that define the character of our inner cities and valleys.

Maintenance in itself is relevant to the retrofit agenda. A wet wall is 1/3 less efficient than a dry wall for example.

Building pathology is equally important. The recent Each Home Counts report for the UK Government highlights the recent case in Preston where the race for energy efficiency and the lack of understanding of older houses has left a trail of catastrophe. The details are being repressed by those concerned inc the Government as it really is a tale of woe, but suffice to say the underpinning issue was the lack of knowledge on traditional buildings within the mainstream construction and retrofit industry.

So we need to understand our homes, their history, how they work. This means getting to grip with material science and building dynamics. A good surveyor should be able to tell you these things, but most just refer on to 'specialists'. Unfortunately most of these are not really specialists, just glorified sales people. So we need 'Power to the People'. These are your homes and you are the ones paying for works to be done. So I urge you to understand older buildings and look after them well. Most of the things that I see when visiting homes are simple maintenance issues that can solve many ills.

As a starter for ten, have a think about the following:

A hole in the junction between a window and a sill. Water running down the window above the hole will go into it. What then? Well generally a damp patch and potentially a rotten floor joist. Solution? Fill the hole with some silicon sealer. Cost? 10p in silicon? 10 minutes in time. Potential savings? £350 for a damp report, £1,000 for DPC injection and replacement plaster, £2,000 for replacement joists,....

A crack in render on a west facing wall. Water above the crack will flow down into it. It cannot get back out if it is a modern cement render. So a damp patch. Rotten timbers maybe... Solution. Fill the crack. Cost? DIY solution, maybe £10. Contractor, maybe £100. Potential savings? Well, see above.

Dislodged guttering pouring water down and into a wall. Replacement bracket cost, maybe £1. Cost of leaving it? Easily into the £1,000's of pounds.

So check things like seals around doors and windows, leaf build up in the gutters, cracks in render, mortar and stonework. Make sure external ground levels are kept 15cm below internal floor levels, that extracts are working properly, that floor vents are not blocked by litter and dirt, that pipes through the wall are sealed up properly, that slipped tiles are replaced quickly, chimney stacks are in a good state and that any repairs are made with lime mortars etc etc.

I could go on. But I hope that you get the message. Preventative maintenance is cheap, relatively easy and essential both in terms of keeping you and your home healthy both now and into the future.

Limewashing the west facing wall

Limewash picture from Heritage Directory

I have spent a lovely few hours yesterday painting the rear of my house using some limewash. I made the limewash using some mature lime putty mixed up with water. The mix is around 60:40 water to putty. I used a plaster whisk to mix up the solution (a very quick job) and then up the ladder.

The first job was to get the masking equipment out. Dust sheets over the ground and windows all taped up and covered with some protective sheeting (old compost bags). If you have never attempted lime washing before it is a splashy business. Limewash has no binders in it like normal paint, so it doesn't really hold together when being applied. This issue was also made the more extreme as my walled are rough cast (so quite textured). The limewash was more slopped on using a large brush than any more glamorous process. Many professional limewashers use large soft floor brushes to apply it as it really is a case of just getting it onto the wall. 

When using lime you should also be careful with your skins and eyes as lime is caustic. I had a small cut on my hand and this 'burned' when limewash got onto it. So, don't do as I do and just get on with it, you should wear goggles and gloves and appropriate clothing.

The process was to start from the top of the wall and work down. The limewash can form quite thick patches due to the roughness of the wall. These will crack as they dry out to form the characteristic limewash finish. These are not a problem at all as they will effectively just create thicker pieces of limestone on the wall, however it is better to apply two thinner coats rather than one thick one. As this was just a quick top up I only did the one coat, but it is possible to apply two in one day and in total many people might find that they have to put on 3 or 4 coats to give them a good period of maintenance free finish.

I am always amazed by limewash and how durable it is. Some old splashes on the ground are still there (from being painted last year) and looking really fresh. So don't think that it is a job that you need to do every year.

The limewash is quite translucent when it is applied and with our lime render being quite red underneath the render does show through when wet. However, as the limewash dries and carbonates it turns much more opaque. So when I looked out this morning it was looking lovely and matt.

In all I did two fairly small walls and I needed one 20 litre pot of lime putty (thus using around 50 litres of limewash). A 20 litre pot of putty costs around £15. So it is really cheap (if you have white walls!) but expect to pay more for made up limewash or for colours / pigments. Even so, it is a really cheap way of painting your house.

So that is the house protected for the next few years, so feeling OK about life at the moment. 

What is the Whole House Approach?

A house is a structure embracing complex systems, embodied history and knowledge, not to mention humans!

We tend to think of houses as being simple structures that provide shelter, security and a place to call home. However, they are in fact, much more than this.

First of all, houses are products of geography, history and society. Geography has dictated the form of many buildings. Think of the different materials that have been used to form buildings in the past. I grew up in Wiltshire where thatch is quite common and there are even some chalk rammed earth houses. Now living in Wales I am surrounded by stone houses.

Geography also places a different set of pressures on buildings. Exposure in areas like west Wales and Scotland is unlike that faced by East Anglia or Kent. Buildings reflect the needs that the weather and topography place upon them. 

History has had wide ranging impacts on buildings. This might be the type of human activity that has taken place in the area (farming, industry, maritime etc), the effects of war and natural disasters, ..... Advances in science have facilitated change by the development of construction materials coupled with advancing building techniques and machinery. Globalisation and the role of the market have also altered how, why, where and what we build. 

Social pressures have also influenced buildings. Where once we would never have dreamed that it was safe or hygienic to have toilets in the house, we are expect new houses to have en-suite bathrooms.

The points above, are only the briefest because the topic is huge, but the principles are there. Houses represent a physical point in time that reflects their origins, but they also then continue to amass these markers in time. People extend and demolish, redecorate, add and remove services, change functionality, follow fashion, .... Each of these changes leaves a mark.

These marks are important. They are largely guided not by specialists. but by individuals. The decisions that have been made are not always the right ones, nor are they always done to a high enough standard. The decisions and their execution are again complex in nature. They are driven by different forces: economics, knowledge, skills, tradition, fashion, material science, ....

So when are are faced with new pressures in the world like: climate change; austerity; fuel poverty; wealth creation these will have an effect, for better or worse, on our buildings. For example, the past few years the main driving factor has been the encouragement to make buildings more energy efficient. This is no bad thing, however we have undertaken this task with self attached blinkers. Everything has been designed with one thought in mind, to reduce carbon and fuel consumption. This in turn has led to serious mistakes and huge amounts of wasted resources both in terms of physical, mental and economic waste. We are now taking out Cavity Wall Insulation (CWI) where is was put into narrow cavities, or into houses in exposed areas of the country, or where is was done without undertaking necessary repairs prior to installation. I fear (and know) that we shall be doing the same with External Wall Insulation (EWI) and Internal Wall Insulation (IWI) in years to come too. All for the same basic reasons: wrong materials used, poor craftsmanship applied, tunnel vision in the design stage, time pressures, funding requirements.

So can a different Whole House Approach (WHA) work and what is it?

The WHA is all about understanding a building, assessing the risks of different solutions, addressing the needs of the occupants (both now and for the future), making recommendations that can be explained and justified, ensuring that the craftsmanship and systems used are of a high enough standard. Ideally the building is also monitored and assessed into the future so that changes can be fine-tuned and lessons learnt and shared.

Building Surveyors should be able to assess a building independently and accurately. However, we need to ensure that they are not taking the easy route and one that leaves stones unturned. It is worth reading my earlier post about the Home Buyers Report and its potential to leave important factors like damp in the hands of 'interested profit making parties'.

Owners need to understand their properties - ain't that a can of worms! Ideally this should be taught in schools, but for now we have to rely on Building Surveyors (and RICS) and the power of the internet to inform.

We also need to have skilled and knowledgeable builders, architects, planners, building control officers, maintenance teams, ....... Yet another can'o'worms! The trouble here is that it does take a really strong and courageous person at the moment to make decisions that are ultimately correct, but that currently fly against the prevailing modus operandii of the construction industry.

For this to change we need changes in regulation, standards and decision making tools. Now that DECC has gone this might mean that a lot of changes that are in the pipeline might get lost, or it might be that the new Department for Business, Energy and Industrial Strategy drives this forward with new vigour! Time will tell.

Anyhow, back to what is the Whole House Approach!!

The WHA is about looking at all the factors that effect a building. We need to address and assess the risks associated with:

Underpinning Structure - What is it? What is it made from? How well was it made? What orientation is it?

Design - Does the building work well? Is easy to maintain? Is it accessible? Is it easy to navigate? 

Social factors - Is it noisy? Do smells waft into un-wanted places? Is it easy to clean? How will any changes reflect in the appearance of the building?

Energy efficiency - Is it easy / cheap to heat? Will it require cooling? Where is the heat lost / gained?

Energy generation - Can the building generate energy? Which technology is best for particular building?

Moisture movement - Is there damp? Will changes introduce damp? How is moisture managed?

Ventilation - Is there sufficient fresh air? Is the fresh air fresh?

Material compatibility - Can we use standard materials or do we need specialist ones?

Water efficiency - Can we reduce water use?

Monitoring - Can systems be used to help owners monitor and reduce resource consumption?

Maintenance - Can low maintenance be created? How can alerts be created to trigger responses to need?

Preservation - Do certain features need to be preserved / protected?

External environmental factors - How exposed is the building? Is there a flood risk? How will it perform in a warming world with more extremes of weather?

External social factors - Is there a skilled workforce available? Are the materials available locally?

....

Starting to get the picture?

The main complicating factor is that all of these are interlinked. 

For example, by wishing to improve the energy efficiency of a wall it will generally require the addition of insulation. This then creates RISKS. Is it compatible with the existing structure? Will it effect the appearance of the building? Will it introduce damp? Will it change the way the ventilation system works? Will it need maintaining? What happens if it put in by low skilled workers? Can you preserve wanted features? When will it be done?

After all of these questions are answered it may be that the better (lower risk) solution is to generate energy instead of saving it. But this needs to assessed and a reasoned solution presented.

So will this work? 

The main point behind the WHA is one that minimises the risk associated with proposed changes. Once we can understand the risks, we can assess them and make informed and hopefully rational decisions. This does not mean that it is a recipe for doing nothing, just that we might make fewer long term and costly errors.

A WHA therefore needs really well informed professionals who are independent, have time to make recommendations, have back-up of accepted knowledge and standards, but most importantly have the support of owners of buildings who wish to create a long-term future for their investment. A start has been made on this process by the STBA and you can access their Responsible Retrofit Wheel free of charge.

Community Work with Renew Wales

Saron Chapel in Treoes

Eco Home Centre is a Rounded Developments Enterprises project. RDE is a not-for-profit organisation that does work with other partners in Wales and one of our main ones is Renew Wales (see www.renewwales.org.uk). Renew Wales is a great concept where experienced community groups help other not-for-profit organisations with climate change linked projects. These projects can cover a wide range of issues: community gardens, community energy, sustainable transport, training and education, .....

We have been one of the mainstays for helping community groups with their buildings. Most of this work is to help groups understand their buildings and also how to refurbish / redevelop them in a more holistic manner. We follow the guidance created by the Sustainable Traditional Buildings Alliance (STBA - see www.stbauk.org) These groups include:

Saron Chapel in Treoes
Nantyffyllon Miners Institute in Nantyffyllon
Kings Church in Newport
Amelia Trust Farm in Walterston
Cathays Sports and Social Club in Cardiff
Harlech Swimming Pool in Harlech
Ysgol Glannau Gwaun in Fishguard
Chirk Scout Hall in Chirk
....

The work has varied from looking at heating systems, renewable energy options, damp and maintenance issues, design and new builds. Getting the balance between social, economic and environmental issues is not easy and I think that we have been instrumental in groups really starting to understand both their community building and their own homes. We have found that people come to Renew with one particular issue and leave with the knowledge that there is a large amount of interlinked factors that they also need to be aware of in order to find the correct solution both for them and their property. Factors like intuitive navigation, noise, access, maintenance and servicing are often overlooked, yet they are vital to the day to day running of a community centre. Just getting people to think in a more holistic manner really has really allowed them to make much more informed and longer term decisions.

If you are involved with a community group, are based in Wales and have a property that could do with some holistic advice then think about giving Renew Wales a call. The Renew Wales model means that the service is free for the group and you will benefit from around 5-6 days worth of consultancy from experienced community practitioners. This advice could be in the form of business development, outreach, training, marketing, fundraising or the more specialist services from people like us.

Brick face failure

This is quite common to see bricks suffering from old age (and occasionally poor pointing)

This is the type of wall that is commonly rendered over (using cement) because the bricks have lost their faces and hence are much more prone to the weather.

The rendering over can of course cause many more problems due to old bricks (with lime mortar) not being compatible to modern waterproofed cements. The obvious answer, assuming that you are happy to render over, would be to use a compatible lime render. This will work with the wall to help keep it dry and also provide it with the necessary protection from the elements.

What to do though if you want to save the look of your home?

Well, getting the same bricks to match is difficult and would require lots of research as many of the old bricks were made by small local factories that have now succumbed to nationals and multi-nationals. Getting a colour and texture match is therefore a bit tricky.

The answer, though, is staring us in the face (apols for the pun). Each of the damaged bricks will have a perfectly preserved face on its other side, so all we need to do is to turn it around! Easy (said.)

Removing the mortar can be a bit tricky, but where the original lime mortar is, it should be much easier as the mortar is softer than the brick. Where it has been re-pointed using cement the opposite is true and this causes more problems. The use of lime mortar is important for this very reason. Mortar in old houses was there more to keep the bricks / stone apart rather than to stick them all together. When we started building thin walls (cavity walls are effectively two very thin and unstable walls) we needed to stick them together using strong cement mortars and wall ties.

Anyway, back to the point. How to get them out. Well there are a couple of tools that are generally used: Angle Grinders and also Masonry Plunge Saws. The main issue is minimising dust. Silica dust can be nasty and so make sure that you wear a mask. Personally I think that it is worth hiring a Masonry Saw (also known as Wall Saws).

Wall saw

Basically, you then cut around the brick(s) in question and then you can remove them, flip them around and reset it back into the wall using a matching lime mortar. Good luck!

Brick turning

Forget Energy Efficiency think Health!

Readers of this blog will know my views on lots of the energy driven 'improvements' that we are blindly doing in the UK at the moment.

We are making so many mistakes due to the fact that we are using more than useless techniques, materials etc in a slap dash manner. All of this is being done with the best intentions, but we are storing up many problems for the future by our haste and lack of underpinning knowledge.

In years to come we shall look back at this period in our history and hang our heads in shame, I think that in the worse case scenarios it will be regarded as a modern day 'asbestos' story.

So how can we change and do this better?

Well, a very easy way would be to think about it all in a very different manner.

At the moment all we can think about is energy bills, carbon reduction, fuel poverty and regeneration. None of these things are bad, but they do drive us into solutions that are not fit for purpose. For any readers not up to speed here there are fundamental flaws with how we measure energy efficiency in buildings (especially older ones), how we measure thermal efficiency in walls and also more importantly how awful we are when it comes to moisture. Have a look at the STBA reports on thermal and moisture measuring for more info.

Now DECC know all of this stuff - the STBA have told them, but it takes a long time to change Standards, Conventions, a whole industry! And then there is the political fallout! So basically we will have to wait a long time before we manage to make things better, so in the meantime we shall continue to make lots of mistakes and install lots of inappropriate measures.

So, as a proposal, should we not think about Health.

To have a healthy internal environment we need to provide:

• Fresh clean air
• Stable Relative Humidity (around 50-60%)
• No mould or damp
• Comfortable internal temperatures that are not prone to overheating
• Sufficient natural light
• Low toxicity in materials
• No off-gassing from materials
• A long term solution that maintains these conditions

To do this we need to have items like:

• Breathable walls (where they were designed to breathe)
• Insulation that is suitable
• Good ventilation that is controlled by Internal Air Quality systems
• Natural materials used
• Low / Non toxic materials used
• Good quality installers / builders

So the basic idea is that, if we can create safe, comfortable and healthy internal environments then energy efficiency comes as a by-product of this process / specification. So we would create good internal environments that are suitable for human beings. Isn't this the point of a building in the first place - to create a safe, sheltered and nice place to spend time with loved ones?

Won't it be great to look at a building and think 'how can I make this a really great place to live?' The satisfaction in making a house a home that you would want to live in and enjoy. After all someone has to live there and shouldn't we make it as healthy, homely and safe as possible?

However if we work within our current unrealistically blinkered parameters we shall just produce internal environments that help to burden the NHS and also provide people with poor quality of domestic life.

So lets start to put people first and I wouldn't mind betting that we shall be able to not only provide high quality space, but also save more money in the long term and reduce CO2.

Wales is in an ideal place to make this happen, but we need to drop using dangerous tools like rdSAP and also BS5250, especially for older buildings.

Getting solid walls to meet Building Regs

Building Regulations in the UK have been interpreted for years as demanding that refurbished walls need to meet a U value of 0.3. Products have therefore been designed using BR443 and BS5250:2011 to comply with this.

Unfortunately, BS5250:2011 states that it is no good at modelling 'in service' situations. The whole model is based on water vapour only, no account for liquid water at all. Not so good when you are dealing with moist walls (AKA virtually all walls built before 1919!)

BR443 is the calculation matrix that gives us U values. This, though, has been shown in virtually all cases to be very inaccurate when assessing solid walls. Caroline Rye's work has clearly shown wide discrepancies with measured in-situ U values with predicted ones from common U value calculators. DECC is taking this very seriously and the STBA has been affecting Government thinking thanks to this key research.

So, given that the tools that we have to use to calculate solid wall U values are, in effect, useless and that the unintended consequences of using non-breathable insulation materials can be as severe as structural failure, what can we do?

Well there is a little used get-out clause in Part L1B of the Building Regulations.

Part L1B states:
Dwellings Exempt from Energy Efficiency Requirements
3.8 Historic and traditional buildings where special considerations may apply
c. buildings of traditional construction with permeable fabric that both absorbs and readily allows the evaporation of moisture

It goes on to say that you should aim to improve the energy efficiency as far as is reasonably practicable and it should not increase the long term risk to the building fabric. It also states that you should make provisions to enable the fabric of the building to 'breathe' to control moisture and reduce the decay problems.

The document also points you towards your local conservation officer for advice. So I would recommend sending them the STBA report on Responsible Retrofit first!

Dr Jo Hoppers work on thermal insulation seems to suggest that the thermal bridging associated with wall insulation is such that even the best detailed Passive House refurbishments will be hard pressed to reach U values much below 0.3, so standard installations will be virtually impossible to achieve these types of figures.

However, within this doom and gloom is there a ray of hope?

Yes!

The U value research by a growing number of people and orgs (inc BRE) show that the U value of these old solid walls are radically better than predicted, so you might already have a well performing wall! The U value of your wall might correspond to the types tested by the STBA / SPAB by Dr Rye, so it is worth checking your wall structure against the research findings. You can then use this to show your Conservation Officer as well.

Using breathable insulations like wood fibre on walls is a lower risk option, but all this depends on the existing wall structure, how it has been altered over time, etc etc. So managing risk is difficult, but certainly using materials that have been assessed and labelled using inappropriate tests raises the chances of 'unintended consequences'. This subject is one that BRE has been looking at for years and will soon publish its research into.

This post was originally published in 2013, but this is an updated version.

Passive House Retrofit

From Bere Architects

Passiv Haus is an excellent German energy standard for building new homes. It is a system that relies on making houses really airtight and insulating. Insolation then provides much of the heat energy for the house. Fresh air is supplied via a Mechanical Ventilation Heat Recovery (MVHR) system. This means that it extracts the stale moist air and uses this to preheat the incoming fresh air. This keeps heat loses to a minimum and hence means that heating bills are virtually non-existent.

Designing for this system to work in a new home requires the use of a spreadsheet called the Passiv Haus Planning Package (PHPP). Using this accurate system one can design a building with a primary heat demand of around 15 kWh / sq m per annum. This compares to a new building in the UK that complies to the latest building regulations, that will have a primary heat load of around 85 kWh / sq m per annum. So this means that Passiv Haus is around 9 times more efficient than a modern house.

But is it possible to make an old house into a Passiv Haus? Well, not even Passiv Haus Institute think that this is really possible, however the basic principles can still be applied. So they came up with the EnerPHit standard. The EnerPHit standard relaxes the requirement down 25 kWh / sq m per annum. So still about a quarter of the primary heating energy of a modern new build.

Sounds impossible? Well for many houses I think that it is impossible, especially where you are dealing with old solid and breathable walls. The risks involved in this type of construction are really too great to seriously contemplate, although there are people who have attempted it. The risks associated with 'deep retrofit' and the use of high performance materials when one is exposed to a fair amount of wind driven rain, increase to an extent where the whole project might be compromised and hence and savings would rapidly disappear.

There are houses, though where this 'deep' EnerPHit retrofit is possible. Most typically this is where you are starting with a modern cavity walled house. Here the materials used and the basic philosophy can overlap with the Passiv Haus concept. However it is still a mammoth task to upgrade a house from 120 - 150 kWh per sqm per annum down to around 25.

To undertake an EnerPHit project one has to have a real drive, vision and passion. A long term commitment to a house is also needed as it takes a while for any savings to start to pay back the capital outlays.

Personally I think that whilst the carbon savings are huge and hence it is absolutely the right thing to do for the planet, most owners will be doing it to get different types of satisfaction. Things like 'better internal environment', 'feel good factor' and 'future-proofing ones energy bills' will be more like the real driving force rather than purely an economic one.

The costs involved has meant that many of these EnerPHit projects have been either done as demonstrations, or by people with too much money on the SE of England. However, we do have a pioneer in Cardiff. To get a glimpse of the work that has been undertaken have a look at this amazing blog. https://www.tumblr.com/blog/mypassivhaushome

EnerPHit is not for all, but certainly there are huge advantages in doing retrofit properly and well and having the discipline of EnerPHit can be key in this. For more information have a look at the Passive House Trust website

Eco Home Centre community work

Some of the more observant of you might have seen that we are a not for profit and that we aim to assist groups and people in Wales to make their buildings more sustainable. Well I thought that it might be time to shout about who we have been assisting.

Over the last couple of years we have been working with Renew Wales and with others to help reduce the issues associated with climate change. To this end we have been involved with 40 groups. Some of the more interesting ones have been:

Egni Community Energy Co-operative. Egni was the RenewablesUK Cymru Energy Startup Winner. RDE (in partnership with Greenfeet Energy Assessors) provided the group with the EPCs required for the community buildings where the PV arrays are housed.

Cathays Community Centre. Now proud possessors of a 5.25kW solar array and a new reception area, thanks in part to the support and overview of RDE.

Chapter Arts Centre also now have a 15kW solar array that is busy keeping their overheads down as well. This was organised through the proactive Chapter Community Garden Group with the assistance of RDE.

Cathays Liberal Club (soon to be re-branded as Cathays Sports and Social Club) has been assisted by RDE with applications for a new PV system. They have also run an International work camp in association with UNAExchange. A refit is also planned using re-used furniture from local charities.

Cardiff Community Energy is off of the ground and has received support from Sharenergy to kickstart a new wave of community energy projects in the city.

Rhiwbina community is now well on its way to creating a new Incredible Edible project to bring a new edge to the garden suburb.

We have also provided indepth reports for community groups on their buildings across Wales from Fishguard in the west to Harlech and Wrexham in the north and all around the SE Wales Valleys. We have helped community swimming pools, arts centres, community cinemas, as well as more run of the mill community centres. 

This work is partially made possible by people buying goods from us through the E shop at www.ecohomecentre.co.uk or by coming through our door in Cardiff to purchase our excellent and permentally reduced Eco paints and finishes. So please help us to continue helping others by using our shop.

Where has that damp smell gone?

No need for these now!

The was always a certain smell when we came back home. That slight dusky smell that reminds you that there was damp in the house. Well, I am glad to say that when we returned from being away at Christmas there was no such gentle reminder.

The mould that has been growing (thanks to the original builders who left the house renderless and with some major defects exposed to some pretty awful weather in the late summer) has been stopped in its tracks. Now, all I need to do is to repaint all the internal areas that have lost their paint / been affected by mould etc.

I am really pleased that our efforts (and that of Welsh Lime Works) have paid off.

In summary we have:

1. Created a drain all around the building so lower the external ground level - this will allow any moisture from the ground to be vented off before reaching internal floor levels

2. Opened up a blocked chimney on the first floor to create a better airflow through the house (the ground floor chimneys house wood burning stoves and so are already open)

3. Removed the cement render from the solid walled and early cavity walled elements of the house and replaced this with a lime putty / limestone dust render. Finished with a white limewash (applied in a hot mix)

4. I have also reset all the guttering to ensure that it is not leaking anywhere

So effectively the house is now functioning as closely to its original design as it is economically viable to do (note that we have not replaced the cement floors with the original suspended floors).

We have experienced some pretty wet weather at times since the work was finished and it should be noted that some areas (concrete block substrate) is still drying out, but the internal walls are now dry and the render is slowly releasing all the trapped water to the outside. 

I had imagined that the drying process would take a lot longer, given that the walls were exposed for so long and that the limewash was only put on late last year, but the project has worked really well and we now have a dry and smell free home. So all bodes well for the future as, apart from routine maintenance on gutters etc, the actual structure of the building is now working in a way that will keep the whole house dry inside for many decades to come. I am expecting that I will need to re-limewash every 6-8 years one the southern and western elevations, but more like every 10-15 years to the north and east (and this is down more to issues of traffic fumes rather than the weather).

Given that I have seen replacement cement render failure in a significant number of solid walled houses within a year of application I think that the added expense of doing it right will soon pay off. It really is a false economy to use cheap materials when all you do is store up more hassle and expense for a future date. So, if you have an old house with a damp problem why not give us a call and we can help you out.

Lime render and doors

Replacement doors tend to be held in place by screws, not inbuilt frames

The door on my house has seen a lot of changes. Since I have owned it we have had 2 doors. The removal of the render showed that the original door and frame must have been at least 10cm wider (there is a pillar of bricks on the far side in this photo).

When we changed the door we fitted a new frame as well. However, this frame is held in place using screws set into rawl plugs in the wall. This gives a firm enough finish, but it does move when slammed, so what to do with the new lime render, will this get affected by repeated use?

Well the thought is that yes the door will effect the render. As the door vibrates the render can be weakened and a really hard slam could shift and crack the new finish. So the plan is to counter this by using a cement and mesh to really tie the frame into the wall. With a firm and secure frame in place the covering render will be protected from any movement.

Purists might be up in arms about this as it is not lime (well cement is a lime, just a particularly hard and strong type), however this is about being sustainable and I feel that having something that will last longer in a potentially susceptible zone is better than having a purer version fail. The other important element to remember here is that the cement will be covered with the lime putty render, so this will be effectively buried into the wall and the lime will keep it dry.

Brick detailing ruined by cement

Lovely brick arch revealed on front of house

If it weren't for the addition of cement render over the years I think that this detail would have been recoverable, however the cement has pulled off the surface of the bricks and also caused them to break over time.

This detail would have been nice to re-instate on an otherwise bland looking terrace house, but without replacing all of the bricks it is just not possible.

The use of inappropriate materials therefore has an aesthetic effect on older properties as well as the fundamental damage that they cause by changing the way in which they work.

The damage is caused by the cement being too hard and strong. Basically the mortar and / or render should be weaker than the underpinning structure. Having a harder material means that it is the structure that is damaged when the outer coating is removed. Mortars should just be there to keep the main structural blocks apart and the render is there as their protective external wearing layer. Instead cement changes this to a system where the render is the dominant player and the main structure becomes it servant. Surely we can see that this is fundamentally wrong.

Anyway, my wall will just be a plain render finish (as planned), but seeing that lovely level of detail that was in the original house just illustrates to me what has been lost through the use of modern building materials on an old property. Shame.

Steel reinforced lime

Stainless steel EML screwed into place over areas with different materials / old cracks

I have been busy on the house preparing it for its new coat of lime putty render. One of these jobs has been to mesh over any major cracks in the sub-structure and where there are different materials exposed. This is because the movement in the house may crack the new render. Whilst this is not catastrophic for the render, it is always better to have an uncracked surface aesthetically.

So I have been using stainless steel EML (Expanded Metal Lath) AND stainless steel screws and washers. So I have been drilling into bricks, mortar and an occasional stone to ensure that the mesh is tight to the wall.

The high spots of the dubbing out had to be rubbed back (using a nasty looking studded float) so that the EML would sit quite flush to the wall.

The only major issue was that I was doing this on my own and the EML is really sharp, even on the main surface, so I have managed to cut my fingers quite a lot!

So the EML now covers the main wooden lintel at the front of the house, a thin brick pillar that was constructed to make the door opening narrower, the zone between an old extension where the bricks were not tied in very well, a wooden strip that runs horizontally along the first floor and the junction between a brick element of the house and an infilled concrete block area (an old door way).

So the wall is getting there for being ready for the render. Welsh Lime Works starting today!!

Cement render = Rotten wood

Removing render exposes timber issues under cracks

One of the other issues that the removal of the cement render exposed was the condition of the wood in the structure.

Admittedly the house has a strange array of wood that has appeared in the most unusual places - joists that go all the way through the house from external surface to external surface. The trouble is that this change in underlying surface meant that the cement render was more likely to crack here. Of course, being cement, it did and this in turn allowed water to get behind the render. This concentration in damp behind the cement of course then fed into the wood.

This is one of the big concerns with cement rendering old houses as it it not obvious until it eventually gives way. One of the many problems that we are storing up for the future generations, by not understanding older properties well enough.

So, if you do have a solid walled house make sure that you maintain any render really well - remove cracks when they form etc. If you do get around to needing to re-render, then do so using a lime based render but also expect to un-earth a range of problems.

I feel that this is a similar situation to the climate change arguments. It is out of sight and so out of mind. It is also largely controlled by large companies with vested interests and so they will not lead the way for change as their industry is profitable as it stands, so why rock the boat, even if you know what you are supplying is ruining the environment (the built one that is rather than the natural one).

Dubbing Out

Haired lime putty render thrown into deep holes in wall

One of the jobs associated with re-rendering the house has been to make good the walls before the main render coat is applied. This involves getting hold of some lime putty render (same as the top coat) and throwing it into the main holes that were left by the removal of the old cement render.

The walls were quite a mess after the initial removal. The cement render is far too hard for the walls and so it takes off lots of the underlying mortar and also breaks bricks etc when it is removed. The removal process also involved fairly heavy equipment in the form of breakers and if they are not used carefully then they too can remove parts of the wall. If using breakers then it is advisable to use lower powered ones rather than being all macho about it. So medium breaker, with a wide chisel end, used in as parallel an angle as possible is the way forward.

Anyway the upshot of the job is that rather than expecting some areas of render to be 10cm deep and others 2cm it is best to 'dub out' the holes to make the surface more even.

The process I have used is to throw the mix into the holes as this gets more air into the mix and hence it cures quicker. I have also had to replace some half bricks. Any exposed wood has been treated using Osmo 4005 and the windows have been insulated into any void reveals. Next will be to sort the various joints in the wall so that any variety in movement of the walls does not crack the new render.

A trip around the block in Canton Cardiff

Part of my walk around the block

We are based in a residential part of Cardiff. Lots of solid walled properties and also some newer infill houses with cavities. Despite the ravages of time that have been served out by well meaning but not necessary best informed builders and DIYers, it still has great character - lots of different colours, features etc all based on a common theme.

All looks rosy then and in fact it is an area in demand as far as estate agents are concerned. Can you feel a but.... coming on??

Letting my casual eye wander across the urban landscape I did spot lots of very common issues affecting the houses, so here goes:

No end of cement render (should be lime based and ideally the mix I advocate)
Cracked render everywhere (letting rain into the structure)
Re-pointing with cement (rather than lime)
Damp proof course injected into bricks (should be into the mortar - if used at all)
Damp proof course holes not filled (thus letting water into the structure above the DPC)
Ground levels clearly above the internal floor level (there should be a 15cm difference between inside and out)
Blocked vents for the floor (suspended floors require good draughts under them)
Paint peeling off of dress stonework (should be left bare, or painted with a breathable paint eg. silicate)
Guttering broken, warped, joints snapped, loose downpipes, .....
Window seals broken (they need to be checked and repaired regularly)
Phone and internet lines roughly drilled through walls leaving holes around them (should be sealed up properly)
PV panels covered in pigeon poo (aerials need to be moved to remove the temptation!)
Letter boxes broken (should be repaired to ensure better airtightness)

And that was a quick 15 minute stroll along three streets!!

Correct maintenance is really important with buildings otherwise we shall see these houses slowly degrade. In the heart of the city we need a well informed population, but who apart from us is trying in Cardiff??

Invisible touching up

I was a little perplexed about which picture to choose for this post and I eventually realised that the only one really is the one pictured.

Basically I had to paint over a mark on my bedroom wall. Now with many paints this touch up would have been visible, but thanks to the anti-static nature of the claypaint it is virtually invisible. Why anti-static you ask, well...

Most conventional paints have oils in them and this has a slight charge associated with it. This static charge attracts dust to it, so over time the walls become dirty. However you would not notice this until you get around to having to touch it up. You are then left with the choice of having a visible repair, washing down the whole wall or not bothering in the first place.

Claypaint, doesn't have any oils in it and so does not actively attract dust to it, so when you have to do a bit of a repair, you can just get the left over paint out (or in my case a small tester pot) and paint it over. Job done.

Although I do have to admit that it took me two testers to find the right colour!! So another tip is to ensure that when you have finished painting your room, decant the remainder of the paint into an airtight jar / container and then remember to label it both with the colour and the room that you used it in!!

Lime and Steel

The difference can make or break (literally) your project

These products do the same job. 

They also look very similar

One will work, the other will not

Fixings are used a lot in the construction industry. My render job on the house is no different. I shall have the following types of metal in my wall:

Expanded Metal Lath (EML)

Stop Beads

Screws

Washers

The EML will be used to tie together those parts of the wall where there are junctions (points where the risk of movement and cracking is most acute).

The Stop Beads will be used around the base of the wall

The Screws and Washers will be used to hold the Beads and EML in place

The important thing is that they are ALL stainless steel. Lime (and cement) attack steel and galvanisation is only a thin coat of zinc over the top of mild steel, so any slight removal of this protective covering will allow the moisture in the render to rust the steel. The galvanised steel will also slowly react with lime and this will cause the structure to fail as the rust expands and cracks the render.

Using galvanised and stainless steel together also creates a electrolytic reaction between the two and this will also lead to the render failing.

So when you are using a lime product it is vitally important that you use ONLY stainless steel (and / or plastic) in your fixings. Don't think that you can get away with using good quality beads and EML and then fixing them with some ordinary screws / nails. It will not work.

Stainless is a bit more expensive than galvanised, but in the long term it is very much cheaper! No point having work done only to need it redoing in a couple of months / years.

It is also worth noting that on a recent visit to a newly built school they had the same problem. All the drip beads had failed and had 'blown' the cement render. So it is not just old buildings where care needs to be taken with regard to material selection and combinations thereof.

Windows shrink with age

Having knocked off most of the render around my house (we are leaving those walls that will not benefit from a new lime render) the original reveals for the windows and doors are fully exposed. This then gives one a chance to see how big the original frames would have been.

One downstairs window has a gap of 3 inches / 75mm each side, so over time my window has effectively been shrunk by 6 inches / 150mm. That's quite a lot of light that I have lost!

What happens is that when windows are replaced we don't hack off the render or plaster to see where the structure is. The windows are measured using the visible reveal. No installer wants to estimate depths that they cannot see and most people don't want to have their reveals knocked around just to get an accurate measurement. So windows get smaller.

When the windows are installed, they do have to 'mess' with the reveal and then you find out that you could have had a larger window, but by then it is too late. The new windows are fitted and the reveals are extended so that the window frame is enclosed with plaster etc. Next time, of course, your reveal is now smaller and the process repeats itself.

I would estimate that around 0.5 - 0.75 inches (12 - 18mm) is lost per fitting, so this would mean that this window has been replaced about 5 times since construction.

One of the other common occurrences with this process is that this gap is often filled with that days newspaper. So, you can often catch up on the news from a couple of decades ago! Nowadays fitters tend to use expanding foam to seal up these gaping holes around your windows which is not so much fun. I am not a fan of this foam and so I have used some fluffy insulation in the gaps to provide a little more warmth (and more importantly) fewer thermal bridges around the edge of the window.

So, if you want to keep your windows as big as possible, you will need to allow fitters to remove the plaster around the window so that they can accurately measure the size of the original window void. This is unsightly and dusty, but it is the only way that a company can reliably measure up. They are not keen on making windows too large or tight as it means that they are responsible for getting it right, so their eye on caution is understandable given the costs of re-making the frames and glazing.

Lime rendering my home

Money where mouth is moment!

I have long been an advocate of treating old solid walls correctly. This means allowing them to breathe using a lime based render (where render is needed of course).

Anyway my house has been suffering from damp for a while and so eventually we have managed to get enough money together to start to put it all right. So we are taking the correct approach of getting the outside done first before moving inwards. So, first part has been to remove all the old cement render from the solid walled parts of the building. Note that we are not taking off the render on the already lime renders timber frame walls, or the newer block cavity walls, that form the end extension on the property.

Front of house is stone, behind door is solid brick wall, next extension is early cavity, still rendered is block cavity at ground level and timber frame above

Front door separates different materials

First floor timber joist exposed. Southern side of building is suffering from rot due to trapped moisture from cement render

I have long been a follower of Harry Cursham at Traditional Technologies (http://www.tradtech.net/) and Welsh Lime Works (http://welshlimeworks.com/) and so I have been very specific about the type of render that will be used. I have chosen the following:

1:3 Mix of Lime Putty (from Limestone NOT Chalk) and Aggregate (and this is one of the keys!)

As you may have read in some of my earlier posts, I see aggregates as being the vital, but often overlooked, element to renders. The aggregate mix that I have chosen is:

1:1 Limestone (3mm to dust) with Sand (50:50 mix of coarse and fine)

The key ingredients are the limestone dust and the limestone putty with the sand acting as a filler. The limestone and lime will do all the work in the render as it is these two elements that will carry the water in and out of the wall. Getting consistency of material, avoiding weak points and ensuring that de-lamination is avoided mean attention to detail!