Refurbishing furniture Earthborn vs Annie Sloan

Annie Sloan Chalk Paint is a well known and respected paint that is commonly used for creating new looks for old furniture. The 'shabby chic' has been very popular and Annie Sloan has been a major player in this market.

Now there is a new kid on the block! Earthborn, who produce a range of natural and breathable paints, have developed a new Furniture Wax to allow its Clay Paint to be a true competitor for Annie Sloan.

So effectively both systems are very similar where you apply the paint to the furniture (claypaint and chalk paint have great opacity and adhesion qualities) and then cover it with a wax. So which one to choose? Well there are a number of factors, but the main ones tend to be colour range and cost.

Colour Range:

Annie Sloan has a range of 32 colours. Earthborn Claypaint has a standard range of 60 (with another 120 in their Professional Range)

Cost: This is split into two, the wax and the paint.

Wax:
Earthborn 400ml Furniture Wax (from us) is reduced at £13.99 - see http://www.ecohomecentre.co.uk/index.php/eco-paints/clay-paint.html
Annie Sloan Wax - £7.95 for 500ml

Chalk Paint vs Clay Paint:
100ml Chalk - £5.75
125ml Clay - £3.50 (from Eco Home Centre)

1l Chalk - £ 18.95
750ml Clay - £ 12.99 (from Eco Home Centre)
2.5l Clay - £ 28.99 (colours) or £26.99 for White

What you gain on the slides one can lose on the roundabouts!! If you want either lots of different colours or lots of paint then it looks as though Earthborn is your answer. If you are waxer and a minimal paint user, then Annie Sloan is your best bet. Let the battle commence!

Which qualifications does your builder have?

Most of us will have no idea what qualifications builders have. We invite people, for a number of different reasons, into our homes to work on our most expensive assets and yet, we don't know whether they are qualified to do so.

Is this madness??

I am currently doing some work for the Construction Industry Training Board on training for construction professionals at NVQ Level 3. Looking at the qualifications from Level 1 up to 3 it does seem that anyone holding Level 2 should be able to do most things on more recent housing stock. So why do we see so many mistakes with common building work?

Last year I was speaking to Cardiff and Vale College and it seems as though a common occurrence is that people start their Level 1 (this represents a basic understanding of the topic and the main basic key skills), but only a relatively small percentage come back to do their Level 2 (this represents the industry standard - what people need to know to be able to do their jobs properly). Where do they all go? Well it seems that some decide that it is not for them, but many others start work.

So in this country we have the ridiculous situation where anyone can put a Builder logo on the side of a van and start trading as a legitimate business. No need for a qualification, no need to show that you understand how buildings work or that you can undertake the more complicated work with confidence, competence and skill.

In other countries you have to have a qualification to build, but not here. So bear this in mind when looking for a builder. Also the marks associated with FMB and NFB are worth noting. They do require a portfolio of work to be seen in order to join, but no official qualifications. So there is some reassurance here, but again no training.

Whilst there are some issues with the standard training, especially since we don't recognise the differences between modern building materials and practices compared to the historical ones required for lots of refurbishment work, it is the best way of at least having an underlying competence. So look for a minimum of NVQ Level 2 for standard works, a Level 3 for more complex requirements and a Level 3 Heritage Skills qualification for work on pre-1919 buildings. If there are no qualifications to be had, then look for a portfolio of work and references.

Good luck!

Green Deal Measures - What are they installing?

On the news that the Green Deal has installed 1,000 measures I thought that I would have a look at what they are actually doing.

I was pleased to see that the bulk of what is being done is really quite standard and unlikely to cause damage to the housing stock. Most of the work is changing people's boilers to more efficient ones (37%) and also the related improved heating controls (15%) and hot water tank insulation (9%). Then there is the standard stuff like loft and cavity wall insulation (10%). The only real surprise was that people are having photo-voltaic systems installed as well (16%). The high interest rate associated with the green deal would counteract the financial benefit accrued by the Feed in Tariff, so one must assume that people are doing it for all the right reasons (ie to cut carbon emissions and to localise energy production).

Not too many people are doing solid wall insulation (14%), so this is reassuring, especially since most of the activity in this area is being completed on more recent solid walls rather than the pre-1919 types. Working on concrete walls is much less risky than brick and stone walls.

So even though I am not a fan of the Green Deal, due to all the issues of the poor advice generated by the software, the cost of the loans and the inaccurate financial projections given, it does have a use. Where people cannot afford the capital for 'improvements' this is a way of giving people access to the money to make some positive changes. So even if the measures prove not to be cost effective for the recipients (although with the price rises recently announced even the poor calculations given might find a 'Get Out of Jail Free' card) at least there are some apparent carbon reductions for the rest of us.

Lime - that's less than half the problem!

Sustainable and historical bodies talk about the need for lime renders and mortars in pre-1919 solid walled buildings and rightly so. Lime is a porous material and will allow moisture to pass through it. This allows the walls to 'breathe' and so can help to keep them dry.

All well and good. However, when you make up a mix of lime render what is the main constituent? Lime? No, the bulk of the material is the aggregate. I think that this can be a problem, because the main aggregate that we use is the cheapest and most common one. Sand.

Sand is not breathable / porous and so if you use lime and sand for renders then all the moisture can only travel through the lime. Given that rainwater is slightly acidic means that the lime will be weakened more quickly. However, if porous aggregates are used (or at least a portion of the mix is made from porous materials like limestone, brick dust etc) then the aggregates will take a lot of this load off of the lime, thus making it last longer. Also if external finishes are meant to be 4 times more breathable than the main structure then having a porous aggregate helps to achieve this. 

Lime with a porous aggregate is also more likely to work in an 'osmotic' manner rather than in a capillary way with sands. This means that it can 'suck' moisture out of walls more easily. So as you can see the term 'Lime render / plaster' needs a little more clarification.

I think that the choice of lime and its associated aggregates needs to be more scientific in its specification, especially since choice might also be driven by a range of other factors including:

Exposure 

Underpinning substrate 

Orientation 

Historical colours of renders

So we need to be careful. The best for renders are a mix of particle sizes and sharp angular edges and so if we allow ourselves to be driven by factors like historical use we need to take care. Many old render mixes were dictated by available local materials and these might not be best suited to the location etc, so planners might insist on a mix that is not particularly appropriate for the building!

There are other issues that surround all of this including:

Sand types (smooth or angular)

Salt contamination

Application methods

However for the sake of brevity, are there any broad recommendations that I can give?  

Well, after much thought I have ended up in the Welsh Lime Works camp where we tend to advise people to use lime putty (based on limestone rather than chalk) with a limestone aggregate, applied with a pump and then finished off with a limewash (again based on limestone). This creates a very breathable mix that allows buildings to work in harmony with nature, but it is worth noting that all projects needs to be individually approached.

Which Cavity Wall Insulation?

Cavity Wall insulation for typical existing homes comes in a number of forms:

1. Beads
2. Beads with adhesive
3. Mineral fibre
4. Foam

I recently looked at a couple of the more popular options in the UK and found to my surprise that there is very little technical information available on them. No technical details on installers or manufacturers websites and when I called one of the biggest installers I was told that there was no-one there who could answer my questions (despite being quite basic) and that I would either have to speak to a surveyor or have an on-site visit. So they are keeping some basic data hidden away. Not sure why as there is nothing really to hide. Also all the sites give out basic info on the process of installing, benefits etc, but there is no mention of any particular issues to bear in mind.

All of cavity wall products are injected and all will do the required insulation job on paper, however there are some major differences between them. I shall also highlight some concerns / factors that you might wish to bear in mind when choosing.

One major factor before you even start is to ascertain whether your property is actually suitable for cavity wall insulation. Many cavity walled properties that were built before WW2 did not have wide cavities and many are also full of builders waste. So make sure that your wall is capable of safely having insulation installed.

Second major factor is: How exposed is the site? Is it prone to wind driven rain? The way that cavities are designed to work is that the outer 'skin' is allowed to get wet and then the cavity keeps the inner wall dry. This means that the walls are actually quite poor at insulating, but that they are at least dry. By filling the cavity with a material, this can allow water to pass from the outer skin into the inner one. Not good! So your outer wall needs to be in good condition with intact render / mortar, not affected by leaking gutters or down pipes etc.

Third major factor is: Are you planning on any replacement doors / windows / extension works etc in the future? Some insulations are loose fill and so if you disturb the wall then they will just fall out. Thinking ahead will allow you to make the right choice in the longer term, otherwise you are just making extra work for you or for future occupiers.

Fourth major factor is: Do you have good seals around anything that goes through the wall? Insulation companies are not good at making good a wall before work. So if you have penetrations through the wall for waste pipes, drains, water connections, gas connections, air bricks etc, or even poorly sealed doors and windows the companies often just fail to inject insulation in these areas. Thermographic images taken on insulated properties often show that cavities are not insulated around 'weak points' like doors, kitchens (where there are lots of services), above window lintels etc. This causes cold spots in these areas and can lead to damp and mould forming.

So back to the choices.

1. Beads - Beads on their own form some of the most insulating choices. The beads that are injected though are loose fill. They can also form a bridge between the two skins. They can rely more on gravity to fill the cavity rather than pressure when installing.
2. Beads with adhesive - These are generally less insulating, but are pressure injected in order to make the glue work. They are regarded as being water proof and so should keep any water away from the inner leaf (assuming that they is installed correctly). The pressurised installation should mean that it is more likely to fill all of the cavity (and blow out of any weak points!)
3. Mineral fibre - These are sold quite often as being fire proof. However, fires in cavities are not very likely and so the toxic fumes from beads are not too much of real hazard. Mineral fibre is also a loose fill, although it does bind together better than beads. It can also form a bridge between the skins if the outer skin fails (just like the beads).
4. Foam - This is not fitted these days as there have been numerous cases where the foam has failed over time and left a right old mess in the cavity. If you did have foam installed years ago then you may wish to revisit the condition of your walls. There are companies who will remove failed foam and re-install a more appropriate insulation. A thermographic image should identify if your walls do have a problem.

Overall then, there is of course a need for cavity wall insulation in many houses, but you need to think about the suitability of the walls, the need for continual maintenance of the outer skin to ensure that it is not compromised and also the choice of the material for the fill. Good luck!

CADW Heritage Cottage U Value data

CADW purchased this old terrace in Cwmdare in order to preserve it for future generations to see how workers cottages were originally built, but also to see what sympathetic improvements can be made in order to bring it up to more modern standards.

This is a balancing act for the team, but they have already done a lot of work to see how the building actually performs compared with our modern expectations. One of the most important elements in today's world is how insulating the fabric of the building is. Walls form a major component of this. If you are a reader of this blog you will not be surprised to find that the walls were actually 30% better than predicted by our modern spreadsheets predicted.

More information on CADW Heritage Cottage and its refurbishment can be found by clicking here:

Ultra Insulating Windows and Doors

Eco Home Centre has a great relationship with ARU Joinery in Estonia. Now the lovely people at ARU have developed a brand new ultra insulating range of doors and windows for the Passive House / Code for Sustainable Homes Level 5 and 6 market.

The Nordic Range is made from solid wood so there is no chance of the frames de-laminating. (De-lamination has been a cause for concern on insulated windows and doors as there is an inherent weak point in the structure.) These frames are chunky at 92mm thick, but this is required to house the 52mm deep triple glazed units. The frames, though, do not look over heavy (despite being very heavy!)

The U values achieved are very impressive. The glazing itself gives a Ug of 0.47 and a standard window gives an overall Uw of 0.78. Compare this to the Building Regulations standard of around Uw of 2 and we start to see how well these windows and doors perform.

The Nordic series of products is wide ranging and includes:

• Inward and outward opening doors and windows;
• Sliding patio doors; and
• Folding patio doors

All are also available in aluminium cladding for extra weather protection for those hard to service areas.

So if you are looking for some great high performance, high specification windows or doors then have a look at http://www.arugrupp.ee/window-and-door-production/products/facades-and-conservatories or give us a call.

Green Electricity Price Freeze and Other Good News

Just had an email through from Ecotricity (whom we use at home, both on our Dual Fuel, but also for the Feed In Tariff for our PV panels), that states:

1. Price Freeze until 2014. So they will be freezing their prices until the New Year
2. 100% Green Electricity tariff is now their only tariff
3. They will cost less than each of the Big Six standard regional tariffs
4. Green Gas will be guaranteed 'Frack Free'

So, with prices increasing for many people, it might be worth investigating a fully green option that may well be cheaper both for you and the planet.

Another option for those in Wales is that DTA (Wales) have negotiated a deal with the big energy boys to reduce costs by a mutual buying arrangement in partnership with The People's Power CIC. So if you are more worried about cheaper prices rather than a green tariff then check out https://www.cheaperenergytogether.org/p/dtaeag/

As winter approaches it is important that we take control over our use of energy and these are two really great ways forward.

Osmo Powergel tested

As I am a believer in trying out all the products that we sell (I always want to be sure that the products work as expected to) and this summer I had a chance to try out Osmo Powergel on my parents oak bench.

I was a little nervous as it does appear to be too good to be true. Just put the Power Gel on, leave it and then wash and brush off using a stiff scrubbing brush. I was unsure as to the effectiveness of the Gel and was expecting the brushing off to do most of the work.

So I was very pleased to see that after a few minutes the old colour of the wood started to show through. After half an hour I could clearly see that the oxalic acid (from rhubarb) was working its magic. The brushing off was easy enough and the wood looked great.

The process does get the wood very wet and so you need to do this on a good sunny day so that it can dry out quickly again.

I then used an Auro product to refresh the bench with a new coat of teak oil. However I was surprised a bit as the Auro product has a tint in it (to give it a UV protection value). I was expecting a clear Teak Oil, but the colour that it gave has proved to be a hit with the parents. This also means that the colour and finish should last a bit longer than using a clear oil.

So, all in all, a successful trial that has proved to be as easy and effective as billed on the tin. So thanks to Osmo and Auro for your well designed products for wood.

Home Grown Hemp is back

Hemp insulation is a fine alternative for the more commonly known sheep's wool insulation, but in the past it has had some issues. The main one being that it was manufactured in France. So the UK grown hemp was being transported across Europe to be processed and returned. Now, however this is changing. Black Mountain Insulation (now owned by IPP) have recovered from their fire and is re-starting a new factory up in Yorkshire. The Norfolk grown hemp is therefore facing a much shorter journey for its processing. This will significantly reduce the carbon associated with Life Cycle Analysis even further (it was already good!)

Hemp is a great alternative to conventional insulation for a number of reasons. It has a high thermal mass (this helps to keep a building cool in the summer, as well as warm in the winter), it is breathable (this allows for moisture to be absorbed and released, thus keeping relative humidity more constant), it is a carbon sink (this ties up embodied carbon into the fabric of the building), it is not prone to moth infestations (this was an old worry about the sheep's wool), it maintains it integrity well (this means that it does not slump over time, which is a common concern for insulation like glass and mineral wool).

Eco Home Centre will be able to access Hemp Insulation after it becomes available from the end of the month, so give us a call and we would be happy to provide a quote for you.

Loft stilts can help increase levels of loft insulation

One of the major reasons why people don't insulate their lofts to the recommended 300mm depth is because they have used the space for storage.

This means that very often the loft has around 100mm of insulation and then boards on top of that which are piled high with old clothes, items waiting to be re- discovered for the Antiques Roadshow, etc. This level of insulation is not ideal and should preferably be increased to the 300mm. Loft insulation companies, however, are not in the business of moving things around for people, so if they find a full-ish attic they will not insulate it.

An easy DIY solution is therefore required. Thankfully there is an easy way to lift the storage level to give you the insulation level that you and your house deserve, whilst also maintaining a solid storage platform. Loft stilts are available from most large DIY stores. There are a few UK made manufacturers:

http://www.loftleg.com
http://loftstoragestilts.com/

So get ready for winter by ordering in some insulation (preferably some natural ones like hemp, sheep's wool or some recycled ones like Warmcel (paper), Non-Itch (plastic bottles) or Innotherm (cotton)), some loft stilts and some screws!

Remember if you do want some natural / recycled insulation, give us a call as we have access to some great trade deals. 029 20373094.

Smoky Chimney Solved

Last week I had my two chimneys lined as they were not drawing very well and some smoke was leaking into the upstairs room via the old chimney breast.

The house originally had three additional fires, one in the kitchen (removed when the extension was added) and two in the upstairs bedrooms. The upstairs ones have been blocked off. One bedroom has had its fireplace removed completely and the wall re-plastered, the one in the front bedroom is still open and is 'sealed' using a chimney balloon. This background is important for what happened next.

I booked in a specialist company to install the chimney lining. I was sure to pick the stronger liner with the 25 year guarantee (904) rather than the 10 year one (316) . Why would you want to save a couple of pounds on a radically inferior product? So note, the 10 year guarantee chimney liner is the industry standard!! So remember to ask for a 904 liner and get something that will last 2.5 times longer, otherwise you might be getting it all done again before you know it.

The liners were fixed to both downstairs wood burners and signed off with their HETAS certificates. Job was a good one.

With great expectation we lit the fire for the first time this week as it was a little colder outside, but mostly because of the fun of having a new chimney liner. It was with horror then that the house started to fill up to smoke. Arrgghhh.

I quickly traced the source to the upstairs front bedroom. All the doors / windows in the house were quickly opened fully. Boy did it smell! So called the installers, they suggested that it might be a 'cold chimney' where there was a thermal block and the smoke was backing up in the liner. Get it really hot and it should work again I was told. So I stoked up the fire and kept fingers crossed. It did slowly get better.

So a few days later, it was time to try again to see if the problem was still there. Sure enough it was, but this time there was much less smoke, but it was still originating from front bedroom. Back on the phone to the installer and they booked to come down in a couple of days time. That day was today and they took out the liner to see if there was a split in it. All fine. All connections tested again, all fine.

So the diagnosis? Well the only explanation was:

The new liner is touching the inner walls of the chimney and this was burning off the remnants of the tar / ash etc of the upstairs chimney and this was then creating all the acrid smoke that was then being forced down the blocked chimney and into the room. All makes sense, so they kindly swept the chimney to remove the excess tar etc and then we blocked the upstairs chimney flue from the bottom using glass fibre insulation. Any tar being burned off should therefore not have enough oxygen to burn and also any smoke should be stopped from entering the room by the compacted insulation. Once the tar in the immediate area of the new flue has been 'burned off' the problem should be over.

So a bit of an adventure, but having had a roaring fire in the stove this afternoon (despite it being nice and warm in Cardiff) I hope that the problem is over for at least 25 years!

So the advice is to think about what any lining might do the internal surface of the chimney and also to remember to ask for a 904 rather than a 316 liner.

New eco-products give hope!

The Dutch Postcode Lottery and Cradle to Cradle competitions have had some amazing finalists this year.

The winner this year's Postcode Lottery Green Challenge was BioMason’s CO₂-free brick production process, which uses bacteria to ‘grow’ bricks! Can't wait to see these around, especially given the amount of embodied energy in a conventional brick.

The other finalists in the American Cradle to Cradle competition include:

• Mushroom^R Insulation – a green replacement for plastic foams, which combines agricultural byproducts with fungal mycelium to ‘grow’ structural rigid insulation
• Bellwether Materials’ Softbatts – sheep’s wool insulation
• GR Green Building Products’ Green Cedar^TM and Green Slate^TM – synthetic roofing and cladding materials made from waste limestone and recycled plastic milk bottles and shopping bags
• Dutch Design Initiative’s reinforced wood wool cement board (pdf link)
• Ecococon’s straw panels
• Haplobuilt’s Haploblocks – a small scale prefabricated building system (pdf link)
• Ecor^R Universal Construction Panels made using waste cellulose fibre.

Great to see such a wide range of ideas being brought forward to help reduce our embodied energy associated with new builds, extensions and also some refurbishment.

Hot loft conversion this summer?

When we think about insulating our lofts we only think about keeping them warm in the winter. However, with summers projected to get warmer, we also need to start thinking about keeping them cooler in the summer.

So insulation works both ways, yes?

Well yes and no. Never easy is it!?

In the same way that solid walls help to reduce overheating by absorbing heat during the day, similarly higher thermal mass insulations are better at keeping peak heat down in spaces like lofts. So effectively if you have a choice between two different insulation materials that have the same final insulation values (for winter heat retention) then the one with the great mass will be better at reducing summer heat and keeping a more constant temperature in the room.

This means that one might be comparing a modern phenolic board (which will be more efficient per cm depth) and a deeper natural insulation. The obvious comparison is between these modern boards and a more natural wood fibre board.

Wood fibre has a higher decrement value (how much it slows peak heat). So each 1 cm of wood fibre will delay peak heat by 1 hour. So during the longer summer days, even a 6-10cm board will remove the peak heat of the day from your loft space.

To illustrate this decrement effect a study from Delft University of Technology in the Netherlands examined two similar houses, each with a roof U-value of 0.21W/m2K – one insulated with lightweight fibreglass and the other with denser cellulose. Both were oriented to the south and remained unheated during the study period, throughout which outdoor temperatures fluctuated by 25C. While the temperature in the fibreglass-insulated house varied by 13C, it fluctuated by just 3C in the cellulose-insulated house. When the temperature outside dropped to 10C, the inside of the fiberglass-insulated house measured 14C, yet it was 18C inside the cellulose-insulated house.

This flattening out of temperature fluctuations in a great advantage in their areas of houses that are most prone to high temperature variations. Worth thinking a bit differently then!

Last note, if you are concerned about head-height, you are correct, it might not be the best sole solution, but using an amount of higher density insulation would still be advisable. 

If you are able to lift the roof level, then using wood fibre sarking boards can be a great way of getting the same effect.

An old bay exposed

The render under the window was harder to get off. Attached to cement blocks that we used to fill gap when bay removed

The front of my house is flat with one large window downstairs. I sort of knew that it was likely that originally there was a bay there given that they exist on other houses in the street. However, it was only when I removed the render from the front (in my bid to stop the rising damp issue) that I confirmed its past existence.

The whole system is a bit of a mess, surprise surprise! The old foundations for the bay were still there, but there were no new real foundations for the new wall. The new cavity wall has been made from a concrete blocks and rendered. A vent was also installed to keep the structure drier (and of course colder!)

To deal with the issue I have, to date, removed the top layer of render and re-applied a lime render. This was mixed with a little cement to help with curing times. I have also installed a render drip to keep the water a little away from the 'foundations'.

The finish has been matched to the treatment used on the rest of the wall (stone), so this is a lime wash finish.

Next job is to remove more of the current 'foundations' and then re-build them with a little more structural integrity.

Ideally I shall re-instate the bay as it would add some character to the front of the house, create a nice seating area next to the window and also allow us to make a more thermally efficient structure. But this might be a longer term 'aspiration'!

Flat roof under pitched roof - An insulation tale

Several years ago, we had an extension put onto the back of the house, over an old flat roof. However the extension didn't cover the whole of the flat roof, so we had a pitched roof put over the remainder so that it gave a more reliable rain shield.

The builders insulated the new roof, but of course they didn't remove the old flat roof first! The insulation was just piled up over the old felt and left. The room underneath this is the bathroom and I had been wondering why it was still quite cold. Lots of insulation in the roof, so should be warm etc. So I had a look. It was then that I discovered what had happened.

So effectively what I had was a vented flat roof with a load of insulation above it. This meant that the wind was venting the old flat roof still and so I was only really benefiting from the amount of insulation that was in the flat roof structure!

So one of my jobs has been to remove the insulation, then remove the flat roof, inspect the insulation in the old structure (I wasn't expecting much!) and then do some remedial works. Fun, especially since the new roof only gave me around 1.2 metres of headroom at the apex. Being a 1.9m tall person, I was expecting a bit of a squeeze. I wasn't disappointed!

So I set about cutting out the old roof with my reciprocating saw and drill. What a lovely job. I had to cut out large rectangles of felt and chipboard to expose what lay beneath. I did this as close to the edge as height would allow to ensure that the final solution would be accessible as possible.  Anyway, as expected I uncovered a right old mixed bag. Some spaces between the joists had 5cm of insulation, some a collapsed 10. Some, none at all. No wonder is wasn't too warm in there.

The solution needed to be thought through, but was in the end, basic. The warm moist air from the bathroom will primarily vent through the extractor, but will also partially vent through the ceiling and insulation (just like in a standard loft). The insulation therefore had to allow this into the main pitched roof space and so I also needed to keep the eaves clear to give the required draught in the void (this avoids the risk of any condensation forming on the now cold underside of the pitched roof). So effectively I just piled up the insulation, that I had removed prior to starting, on top of the exposed ceiling boards to a depth of around 30-40cm and kept the required 5cm gap at the eaves for the ventilation.

Not so worried about autumn and winter's imminent arrival now, though will keep a check on the moisture issue since the insulation that I re-instated is recycled plastic rather than my preferred warmcel insulation. I would have preferred the recycled paper since it is breathable and hence any excessive moisture would be more easily transmitted through it than the plastic. Still another job done.

Cracks removed and new unconventional render applied

When doing my holiday work, one of the objectives was to remove the micro-cracks in the cement render on the house. These hairline cracks are terrible for letting rainwater in and then trapping it in the structure. Hairline cracks are really important to remove, especially on walls facing the prevailing winds (as the wind drives the water into the cracks) and also where any excess water is running down the face of the wall.

Oddly enough large cracks are less troublesome most of the time as any water can also evaporate off as well as seep in, however with the hairline cracks the evaporation is effectively eliminated.

Given that I wasn't prepared to remove all the 1970's applied cement render I merely wished to remove the cracks by widening them and then re-rendering using a breathable render. So I cut away the existing render using a disc cutter, then hacked off the render either using a bolster or the breaker that I had hired.

Of course what I exposed was more problematic than originally thought. The cracks were being caused by two factors. Firstly I found that the roof lead was channeling some rain water behind the guttering and into the wall, so I repaired this. Secondly, the wall underneath was not tied in very well (it was an extension at some time) and that past work had used a galvanised mesh to tie the render together. The mesh had of course rusted and hence helped to cause the crack.

I used a mix of hydraulic lime, sand and a splash of cement to do the repairs and to fix in the lime resistant mesh. The following day I mixed up the amazing Insoplast Insulating Plaster to render the repair. This will be treated with a breathable silicate primer and paint at the weekend.

The reason for using the Insoplast was not driven by primarily by its insulating properties (although these are a real bonus), but due to the fact that it doesn't require a wet substrate. It is put directly onto a 'dry' surface. This meant that I didn't have to introduce any moisture into the wall.

You can see from the above that I did two cracks in the wall. I also ended up doing the lower level of the wall. This was because I found that the lower render was very loose, and although not blown in the classic sense, it certainly had lost any real effectiveness. I again used the Insoplast plaster here and a stainless steel drip bead. Galvanised drips will slowly rust and blow the plaster, so even though the stainless was more expensive, it will save money in the long term.

Fingers crossed this work will help to keep the wall dry, a little bit warmer along its base and be flexible enough to stop any more cracks occuring.

Anti-slip treatment for wood flooring

Recently I had a query from a commercial company who had been having trouble with people putting in claims against them for injuries caused by slipping. So after a bit of research I found that slip resistance has a scale. The majority of domestic floor finishes have a rating of R9. Even many commercial products are a R9. Osmo Polyx Oil and the Osmo Pur fall into this category.

A bit more digging and I discovered that the insurance industry requires a R11 rated floor finish in order to cover injury claims against slippage. So the hunt was on to find a suitable R11 rated floor finish from an eco-friendly manufacturer.

Thankfully we are an Osmo stockist and despite a R11 rated finish not being available from Osmo UK, we managed to get a shipment across from Germany of the 3089 Hartwachs-Ol Anti-Rutsch Extra! This is a R11 finish and also based on natural oils (a la Polyx Oil). Unfortunately the paperwork that accompanies the product is only in German, but it is applied in the same way as the Polyx oil.

A permanent damp solution?

The history of my drive way next to the house has been a voyage of discovery thanks to my neighbour. I live at an end terrace and there is a shared driveway between it and next door. It is a concrete drive that butts right up against both houses.

Now this drive way was originally two garden paths and a stone wall, but it was converted to a driveway to open up access to the back. This is a fine thing, but it has been through a few changes over the years. I have been discovering these and the also living with some of the consequences.

The paths were not taken up, just tarmac put over the top. Several years later concrete was put directly onto the tarmac. Of course this should not be done as the tarmac disintegrates under the concrete, but more important for me was that the height of the roadway was now above the level of the floor in the house! No wonder we have damp in that wall.

So I have had to cut out the roadway using a disc cutter (a diamond blade worked a treat) to get a 'straight' edge. I marked out a line with chalk, but the dust from the cutter obscured this quite badly so care needs to be taken when doing this.

My attempt at a straight cut to make the initial trench at the side of the house

I then set about smashing up the concrete with the breaker I had hired. Fair Dos the breaker was great. However I discovered the tarmac. So my first pass with the cutter only got me through the concrete. The tarmac though had failed and so was quite easy to remove. I did though have to use the breaker again. After a third round of breaking and shovelling (well using a trowel) I eventually got to a difference of between 20cm and 10cm between the floor level and the outside ground. So I now have a 15cm drain between the road and the house.

The concrete road broke up nicely with the breaker

The work involved taking off the render off of the walls from this low level. Knocking this render off was really satisfying. You could also feel the walls breathing a great sigh of relief as the old render and road way were removed and bricks and stone exposed (with their sodden lime mortar!) Surprisingly the wall from the door back turned out to be a brick cavity wall! This is an 1880's house with solid stone walls at the front and back. Finding a brick wall was therefore quite strange.

The damp was in evidence when the road level had been lowered down

I then repaired the road way using a concrete mix to shore up the edges. I did this as the road despite being a good 5cm thick could have failed along the edge. I also then did a lime and cement mix for the base of the drain. This will allow any rainwater to flow down to the road and away from the house. I angled the drain so that any water is kept away from the wall. Using a lime mix was there to ensure that there was some breathability in the structure so that it was not just trapping ground water in the area next to the house. To give an extra bit of strength I used some lime tolerant mesh in the structure as this should give it a bit of extra stability and strength. The lime will also help ensure that there is no cracking since it can flex a bit unlike a pure cement mix.

The new trench was lined with mesh and then thinly covered with a lime rich cement

This shows the re-rendered wall, the exposed lower wall and the new lined trench

So the job looks OK now and the water is draining away nicely. Only time will tell if this is the long term solution to the damp in the wall, but already I can see the walls drying to the outside. Fingers crossed they will continue to dry now that they are not constantly damp from being under road level.

Rotting wooden beam

Not my rot, but it looks quite similar!

Whilst the family are away on holidays I have been practising what I preach. Sleeves have been rolled up and the 1890's Cardiff end terrace is getting a bit of a once over. I will tell you a couple of tales of the coming weeks about my experiences - there are a few already!!

I will start with the unexpected one.

The house has a history and part of that was a council funded make-over in the seventies. Cheap stairs, poor re-wiring, removal of original features, concrete floors, 'damp-proofing' and a new cement render. Arrggghhhhhhh!!!

This particular post is about the joy I found when I took off the cement render on the side of the house to fix a crack in the render. Only a tiny one, but I know the issues associated with this type of fault. I cut out the render using my new angle grinder and knocked off the render, to find that the original house has a 8 by 2 beam / lintel running through the house, right up to the render finish.

The crack in the render had, of course, been allowing water in behind the render and keeping it there. This of course was then fed right into the end grain of the timber. Guess what?? Yes, a lovely rotten beam. So my little repair job has turned into a major disaster! But thankfully I know that there is a problem. Better to find out now rather than when the upper internal wall collapsed! Actually that is over dramatic as the beam is thankfully supported by some 4 by 2 uprights internally. However, this is a happy coincidence rather than good planning! If we didn't have a stud internal wall at that point (and this would be quite feasible) then the whole of the back of the house would be at very high risk of sudden failure. Not a pleasant thought.

So I have treated the wood and will be repairing it so that it should last another 120 years. However it is a clear example of how cement render can seriously affect a house structurally.

The only positive is that it is reassuring that my belief that using the right materials is really, really important when working on old properties. If the wall had been treated with a lime render then the dampness would have been kept away from the end of the beam more. I cannot blame modern materials completely, as the beam should not have been pushed all the way through the wall in the first place - 19th Century builders can be as bad as 20th and 21st century ones! However, the use of modern cement has certainly contributed to its demise.

The treated wood will now be encaptulated in a lime based render to help keep it dry and hopefully now rot free.

To come:
Render removal and French drain installation
Flat roof issues
Oak posts set in the garden

New washable Eco-paint - It's Lush!

Earthborn have been busy. Thanks to a request from the Lush chain of shops, they pulls sleeves up, dug deep etc and have come up with a new washable eco-emulsion. Based on their excellent EcoPro range, the new formulation has a silk finish but maintains the coverted EcoLabel.

It is water based, with no oils or acrylics, breathable and free from all harmful emissions and VOCs which means it is not only eco friendly but also helps create a healthier, more comfortable living or working environment. The new paint will be initially available in the Eco Pro colours, so some standard colours like Magnolia, Gardenia, Platinum etc. Despite being an industry flavoured range they are still great colours both for homeowners as well as landlords and tenants.

Eco Home Centre is retailing the new Mid-Sheen as well as the Eco Pro Range of paints, so visit our store to help yourself to a great new product at a permanently reduced price.

Superhomes on show

Superhome network can be found at www.superhomes.org.uk

It is worth knowing about the Superhomes network that exists in the UK.

This is a partnership between a number of organisations and even though they have been really focused on carbon reduction, some of the work done is of really good quality and you also have an opportunity to visit some of the homes through their events. Talking though work with people who have planned and sweated over their homes and who are now reaping the rewards is always useful and inspirational. Check out the events diary on the website to see if there is an open home event close to you, or that you could go to on a trip out. See http://www.superhomes.org.uk/

The site also has more information on refurbishing your type of home. It is not just for solid walled buildings, but for any refurbishment. So there is info on cavity walled properties, system builts etc. Their FAQ section is OK, but there are some mistakes / high risk recommendations that I would not give out as an overarching advice. However, hearts are in the right place and there is plenty to learn from.

Examples include people insulating their homes, fitting new heating systems, installing renewable energy, changing control systems etc.

Tips for French Drains

Drying out your home starts at the foundations

Moisture is always on the move in solid walled buildings. We are constantly asking our houses to cope with water from cooking, breathing, rainfall, soil etc. Using nature to help us cope with this is the best way of managing these pressures.

One of the ways of reducing the pressure on walls, especially around the ground, is to give the walls an opportunity to release the water before it starts to cause internal damp issues. Ensuring that you have at least 150mm (6 inches) between the internal floor level and external ground level is really important. If your house doesn't have this then you would be well advised to provide a well drained area around the wall and foundations.

Putting large stones / gravels around the base of the wall (especially when combined with a perforated drainage pipe) has two effects: 

1. It allows rainwater to drain away more easily into the surrounding soil / drains

2. It allows air to circulate next to the wall and hence help dry it

So it is a good idea to have a drain around a solid walled building (as long as it doesn't affect the foundations). However, digging this out is a bit of a job and the last thing you want is to see it get compromised by an influx of small particles (dust, soil etc). This will just slowly clog up the system and eventually reduce the effectiveness of the system. So is there a way of stopping this from happening?

Thankfully the use of commonly available geo-membranes can help to stop dirt from getting into the system. So after you have dug out the trench (and potentially installed a perforated drainpipe) line it with some garden geomembrane (we would recommend a heavy guage system) so that the channel is lined along the bottom and up the earth side of the channel (allowing enough over to cover the channel and up the wall 10cm once filled). Then fill up the channel with large stones / old bricks etc almost to the level that you want. Once done then fold the geomembrane over the stones. The membrane is then held in place with smaller gravel that is spread over the top.

By having a slight lip on the geomembrane next to the wall means that if you need to do something to the drain then you can pull this back and not risk dropping the chippings into the channel itself.

Happy digging!

From grey wood to great wood

From Waltons Shed blog - thanks

It is at this time of year that we are out enjoying our gardens, but many of us are sitting on tired looking furniture. UV light degrades wood slowly but surely and as part of this process it creates greyed surfaces on our tables, chairs etc.

Getting the furniture back to looking great can be important, both for looks and for its longevity. However many of these types of products are not very eco-friendly as they tend to use acids to strip back the top layer of the wood to reveal the less effected wood underneath - therefore refreshing the look.

Osmo PowerGel is one product though that is eco-friendly (it uses oxalic acid that is found in rhubarb leaves). This is a fully biodegradable product and has also been designed to be easy and safe to use. A video from Osmo can be found here showing the Powergel in full flow!

Eco Home Centre sells the Powergel and also the various Osmo wood oils that are suitable for furniture. This range of products will help keep the furniture looking great but also has the great advantage that when reapplying the oils in future years you don't need to sand the surface back. Osmo works with the wood rather than sitting on top like lacquers and varnishes. This makes it much easier to live with and so will help reduce maintenance of your now great looking garden furniture!

Internal Wall Insulation on Solid Walls

This is a typical industry standard way of insulating solid walls internally (IWI). Use a high performance insulation board (or between stud) with a vapour control layer. This appears to give a great new U value (better insulation) for the wall and also deal with damp.

The implication is also that the more insulation that you put on the better the wall performs thermally. This is a quick and easy solution for cutting carbon emissions, surely?!

Well, if you have read my other posts on U value calculators and damp predictors then you should know that there are several alarm bells ringing.

1. The existing wall is probably performing around 70% better than you expect.
2. The accreditated insulant and system has only been assessed for water vapour movement, NOT liquid movement

Work by Dr Caroline Rye and Jo Atkinson (nee Hopper) also highlight some more issues.

Dr Rye's in-situ testing (i.e. measuring what is really happening) shows that the movement of water in the wall can be seriously affected, so much so that by applying non-breathing insulations with vapour barriers etc can actually pull water into the wall. The 'dew point' is also brought further in the wall and the chances of it happening are increased. This means that it is more likely that water will be sitting around delicate areas of the wall like joist ends. This is a major concern.

Jo's work (and some new work that is currently on-going) also shows that poor workmanship of insulation can lead to thermal bridging. This thermal bridging was mean that levels of insulation beyond a certain level become fairly meaningless. Evidence seems to be suggesting that any more than 60mm of conventional insulation on internal walls is fairly pointless as the heat will just escape through the thermal bridges. So more is not always best!

So IWI has it's issues. Is there an easy answer then?

Well there certainly appears to be an easier way of maintaining a much healthier wall. This is to use a breathable wall insulation (without a vapour control layer) with a breathable finish over the top (a lime or clay plaster finished with a breathable paint for example). This advice translates into something like using 50-60mm wood fibre boards and ensuring that reveals are also insulated as much as possible (this tends to be a 10-20mm board as a maximum due to space constraints).

By maintaining the flow of water vapour through the walls from inside to out allows the wall to operate as it was designed. It also allows liquid water to show up, so if there is a problem with a leak, rising damp, etc then at least you know about and can fix the problem before it starts to affect the wall adversely.

By having a slightly 'less efficient' system for the wall allows a little more heat into the structure and this means that the potential for any dew point is reduced to within very safe levels and also kept closer to the outer elements of the wall and hence away from joist ends etc.

So even though on paper this type of solution appears to be the worse option for carbon savings, actually in the real world it is the best option. It will give you thermal comfort, a healthy internal environment, natural humidity control, a safe structure, visible contact with the wall and also have less embodied energy in the products.

CADW's Heritage Cottage

This is great find for Wales - an almost untouched period terrace from 1854. CADW have purchased the house and are doing a lot of research on the property that will help inform how we should all look after our terraces in Wales.


CADW are looking at how the house functions now and then investigating how to make it more sustainable for the future. So things like insulation, glazing, draught proofing, damp, low energy heating and lighting etc.


The great thing is that the figures that they will be using will be the correct one! It is not being assessed by the blunt instruments like EPCs, they are taking real readings like in-situ U values, thermagraphic images etc. The lessons that will be learnt from this will be really important as they could and should inform us all about what interventions are better for this type of solid stone walled house in the climate / weather that Wales enjoys.

As a starter for ten CADW have produced a short You Tube video about the project. Well worth a few minutes of your time if you own a Welsh terrace!

What are breathable walls?

From http://www.ewht.org.uk

I have come across a few people who when talking about breathable house structures state that they keep their windows open a bit and the chimney helps. The term breathability / breathable does conjour up images of lungs and hence the passage of air through a wall. However, what we are talking about is moisture transfer.

The mainstream industry narrows this down to the transfer of water vapour. However, when looking at older solid walled buildings we actually need to think of breathability as the transfer of moisture. This means water as a liquid as well as a vapour. Anyone with an old house will recognise this as being a major difference and one that can cause a host of problems: After all rising damp, driven rainwater ingress, etc are liquid water issues.

So in order to make good decisions we must accept that for older houses we must think of breathable walls as one that allow the movement of water through their structure.

The general rule of thumb (even for modern timber framed buildings) is that the outer elements of a wall should be between 4 and 5 times more breathable than the inner elements. This means that a gradient of moisture transfer is maintained in the structure where water is encouraged to move from the inner elements to the outer ones. By allowing water to pass through to the outside keeps the inner elements free of damp. The outer elements are allowed to get wet, but the thickness of the structure means that any external water should remain in the outer elements (issues like poor maintenance can still affect the workings of breathable walls).

Materials have different porosity's and hence understanding how 'breathable' they are is really important. Other factors like surface area, orientation, shading, climate are also important, but the breathability of building materials is key. I shall not go into detail here, but understanding the principles of breathability is vital to making informed decisions over renovation / refurbishment work.

If we close off the breathability of a wall by using materials like: insulated plaster board, cement renders (especially those with water-proofing in), conventional paints, we are starting to interfere with how it works. These modern materials are designed to be waterproof (even if they have a degree of water vapour breathability). So if we apply them to the outer elements of buildings we are asking for trouble. The way out for water from the inner elements is blocked and hence the concentration of water will start to increase in the wall. This is made even worse and potentially dangerous when liquid water is not stopped from entering the wall (e.g. rising damp, wind driven rain, leaks from guttering, poor seals around windows / doors etc). This water just sits in the wall and can start to rot joist ends, transmit heat more effectively, cause mould, ...

Even making the inner leaf less breathable by using conventional paints, modern insulations etc can cause problems. Breathable walls mainly dry to the outside, but water is also given off to the internal environment. By stopping this you will find that paint can start to peel off, that condensation  issues are made worse and ultimately that the moisture gradient changes from internal to external to being external to internal!

Messing with a solid walls' natural breathable state is fraught with hazards. Maintaining the wall's breathability is therefore really important. So don't get fooled by conventional materials that state that they are breathable and suitable for solid walls, they are only using measurements for water vapour. You need porous materials for porous walls.

Damp and lots of important numbers

At present the Standard BS 5250:2011 is used almost exclusively as the sole test of moisture risk for buildings. This Standard provides advice on the avoidance of internal surface and interstitial condensation caused by the movement of water vapour by diffusion through the building envelop from the interior to the exterior.

BS 5250:2011 refers to BS EN 13788:2002 as the means by which this risk should be calculated using a method commonly known as the Glaser Method which uses vapour pressure differential and temperature conditions to predict occurrences of condensation occurring either within or on the interior surface of building fabric.

So far it all sounds OK - lots of numbers and big scientific words; surely we can trust British Standards?

BUT!!

BS EN  13788:2002 is clear about its limitations and states "This standard deals with critical surface humidity and interstitial condensation, and does not cover other aspects of moisture, e.g. ground water, precipitation, built-in moisture and moisture convection, which can be considered in the design of a building component" (p. 3). And BS 5250:2011 is clear that designers need to also consider "the much greater risk of condensation occurring as a result of air leakage, which transports water vapour through gaps, joints and cracks in the building fabric" (p. 5) as well as the effects of exposure to sunlight, clear night skies, wind and driving rain, particularly in exposed positions subject to high wind speeds.

Whoops, so nothing in the standard about water as a liquid, faults in the walls, wind driven rain, cold nights, sunshine and rising damp!


Also BS 5250 & BS EN 13788 only assess the movement of water (as vapour) in one direction,
from the interior to the exterior, the use of this standard to assess retrofit solutions commonly advises the use of a vapour control layer in combination with insulation to limit and slow the quantity of vapour from the internal space that can be admitted into the building fabric. However, what about water getting in from the outside?

In Wales this is particularly important as it has been known for us to experience wind and rain at the same time. 

The answer is that water coing from outside to in, is just not taken into account. The vapour control layer helps to stop movement of water, but this means that it helps to trap water in the outer layer of the wall. This build up of moisture in the external side of a solid wall can cause a number of major problems like rot in joist ends. Not good!

Virtually all the well known Internal and External Wall Insulation products have been tested using BS 5250:2011. No wonder they all pass the tests and are 'recommended' for use on solid walled buildings. The whole testing regime is not fit for purpose. A major problem one thinks.

There is an alternative standard available to assess moisture risk in buildings, BS EN 15026:2007
Hygrothermal performance of building components and building elements. Assessment of  moisture transfer by numerical simulation. Unfortunately this is not widely used as there is too much vested interest in the status quo.

So, who cares if the products used in refurbishing solid walled buildings are inappropriate?

The companies making and supplying products made to BS 5250:2011? One thinks not.

Probably only you and the people who will live in the house in the future. But does the average person know the difference between BS 5250:2011 and BS EN 15026:2007 and how this applied to products????

The movement of moisture in a house is really important and we should be using the best tests that we can to ensure that we use appropriate materials, but unless tests and knowledge change we shall be left with using products that are 'recommended' and 'comply to British Standards' but that are, in the real world with water, not fit for purpose. This of course will not happen overnight nor without a fight from the big boys in the construction industry, so it is up to you to demand suitable materials both for the health of your home and your family.

Please share this and other posts with friends who live in solid wall homes.

Thanks to STBA Moisture Risk Paper -­ Dr Caroline Rye & Neil May -­ 3rd August 2012

Can refurbished solid walls reach 0.3 U?

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, even 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 breathable 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 virtaully 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.

Good luck!