External Wall Insulation

griffloc

Has anyone had problems with external wall insulation? Ours was installed in 2013 and we were told by the installer it would solve our problem with rainwater penetration, the Energy Saving Trusts website also said this at that time and the manufacturers website said it was a sealed weatherproof system so we thought we had the right product for us. - WRONG - we now have rain coming into the house much worse than before and we have spent the last few years and most of the money that was supposed to improve the inside after it had dried out trying to get the perpetrators to put it right. Government is rolling this out across the country to tick their carbon saving box but unless you have a really good installer it's pot luck whether you get a decent job done and one which will actually produce the energy savings expected, let alone get the correct assessment of whether your house is suitable. There is at least one manufacturer (yes the same one as ours) who is claiming more clearly than before that this product will stop water ingress and damp, yet their BBA certificate says it shouldn't be relied on as weatherproofing, moisture penetration should be dealt with separately and walls must be adequately weathertight prior to application - oh how we wish we had known of the existence of BBA certificates before! We've set up a website so people can learn from our story - search for houseinsulationhub and see our Facebook Group - An EWI Failure (External Wall Insulation). We've found many reports showing numerous problems and unintended consequences with retro insulation of properties and it looks like there will be many more unless the industry is made to pull it's socks up and improve how these works are done

teneighty

Read your report, very sad state of affairs.

I did a lot of EWI contracts in the late 90's and the workmanship on your house is truly awful. One snippet of advice I would give is that the window sill details are totally inadequate.

It is very important that any rainwater is shed away from the cladding. When I did it I always specified an aluminium undersill that sat underneath the PVCu window sill that threw the rainwater running down the window a good 50-75mm off the face of the cladding.

Your detail where the old rendered/stone sill have been recreated will allow the rainwater running off the window to soak into the large sill and get into the fabric of the building.

Remedial work would be to remove the windows, install the aluminium undersill and refix the windows. Also look at all similar areas with a horizontal step in the cladding and make sure the top has a weatherproof capping. Likewise the slate capping on the East gable is inadequate.

From your evidence I would have thought you stand a very good chance of a successful claim in court or specialist arbitration but if the company has no assets then it would probably only be a moral victory. Might be worth investigating independent arbitration or otherwise small claims/MCOL just to cover cost of urgent remedial works.

FreeBear

My gut feeling is that the whole lot needs to be stripped off. In places, it looks like you have solid stone walls - if this is the case, then the cement daub also needs to be removed along with any cement pointing. Once back to bare brick & stone, fix the issues with water ingress, repair the exterior using appropriate & sympathetic materials. Let the walls dry out properly - this could take a year or more depending on the wall thickness.

Internally, the water bubbles forming under the wall paint suggests that a latex paint has been used - This will seal moisture in to the walls and exacerbate the cold damp feeling of the building. Depending on the extent of damage done to the plaster, it too may need stripping back to bare brick/stone.

With the remedial work completed on the fabric of the building, you can start to look at insulating the walls properly - If it is indeed solid brick/stone construction, woodwool or cork boards externally with a lime render will help. However, I'd favour insulating internally using a studwork infilled with rockwool or fibreglass insulation. Again, woodwool boards with a lime plaster finish.

None of this is going to be cheap, and trying to patch up a bad job is only going to lead to failure in the long term.

griffloc

Thank you teneighty and FreeBear. Sorry to be so long replying, been looking after my 96yr old mum and battling the EWI industry. An independent compliance company now says we have a category 1 failure.
The insulation industry needs to take responsibility for mistakes rather than closing ranks and trying to hide them. Our experience has been made worse by the industry in general refusing to accept honest appraisals of the work here, instead trying to make out that the job has been done to a reasonable standard and saying any problems are an 'unrelated construction issue'.
The manufacturer approved the windowsill detail saying new methods are discovered all the time and they were happy that this way was ok.
The workmen seemed not to subscribe to the view that water runs downhill and driving rain will find it's way into the smallest gap and even the M.D. thought laying lead strips without any sealant or overhang would stop rain getting in!
Not keen on internal insulation as reports say that decoupling the mass of the building causes the structure to remain damp with detrimental effect on timbers and masonry. (We've learned a lot about retro insulation including 'unintended consequences' e.g. cold bridging, interstitial damp, condensation in lofts due to reduced ventilation.
We don't have anywhere near enough money to put this right. An estimate in 2016 was around £58,000 and a new inspector with the manufacturer said that was about right to remove the EWI and make good. (Also said they had removed EWI from a 75,000 sq m house recently at a cost of £30k).
Interior paint used was a bog standard interior silk emulsion and done a few years before the EWI to cheer up the room a bit. It rained before the paint was dry so we were left with the 'swag' effect.

that

Sorry, but I do not understand how the rain gets in to do all that damage? Where does it get in, must be at roof level to go all the way down your walls like that? Eaves not large enough?

road2manchester

I have done a lot of gutter and roof work in the past, one of the most common water ingress problems I saw was the old style felt at the bottom of the roof breaking up and letting water down the cavity or internal wall.

Other than chimney stacks this was 70% of our work adding a mtr of membrane under the first 4-5 roof tiles when adding gutters etc: Same with dry verge caps.... might be worth looking at that before any massive costs. If it was getting in before the EWi it has to be the roof or as above windows.