# Cavity wall not closed at gable end !



## RWbuild (9 Apr 2014)

Hi

We built our house over 2 years ago, went down the self build route, everything went great(or so we thought), very happy with the house etc.. 

BUT, we have cavity walls and it turns out the gable end of the walls the cavity was not closed, as the builder at the time said the roof membrane and the fact we were pumping the cavity with beads that this would be sufficient to close the cavity. Of course we now realise he was completely wrong but the house is built now. I really want to try and remedy this, but cannot afford to do major work on the house at this stage. The block layer is no longer in business (suprise suprise) and is no longer in the country.

our walls are 100mm block, 150mm cavity pumped with warmfill silver bead , 150mm quinlite block. we used qwikfix wallties to reduce cold bridging, built the house airtight and have a mhrv system in place, with a 2.6pa airtight test result.

We had an architect who regularly checked the house and signed off at various stages for us, he never noticed or mentioned the problem with leaving the gable end cavity wall open. The pumped bead insulation guys never mentioned that not closing the cavity would significantly reduce the affect of the pumped bead insulation either.

Apart from needing to close a cavity for fire safety purposes, and vermin etc.. if the cavity is not closed and the cavity is filled with pumped insulation is it correct that this insulation will not work very well as there is constant cold/fresh air coming into the cavity. 

Has anyone resolved a problem like this or heard of cavities being left open like this. Or even if a cavity is closed can air still penetrate into the cavity ? 

Sorry for the long post, but just trying to get my head around how we should resolve this problem, I will contact the architect and also the insulation guys to see if they have any advice. I am thinking possibly that maybe some type of foam insulation at the top of the gable would hopefully work at closing the cavity and making it fire safe.

Any advice at all would be greatly appreciated.

Thanks

RW


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## lowCO2design (17 Apr 2014)

RWbuild said:


> ...self build route..........I really want to try and remedy this, but cannot afford ............
> 
> 
> 
> ...




 not without major surgery
 yes
hilti firestop foam but how can you be sure it completely closes the cavity?
may i ask how many people have you told: 


'we self-built','saved a fortune'?
AND how many have you told 



"it turns out the gable end of the walls the cavity was not closed" 2I really want to try and remedy this, but cannot afford to do major work on the house at this stage"?


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