Damp again - removing cavity wall insulation

baboboy

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Hello. Our builder has started on refurb of our barhroom and fit all new windows. He’s fitting lintels as he fits the windows. As you may recall earlier in the year I queried some damp. Our builder thinks some of it has been caused by the cavity wall insulation. I’m tempted to get it taken out. What I can see it’s a fibrous sort of material. Has anyone had it removed. Any idea of costs?
 

Dave

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I've taken it out of a very large house and it is a hell of a job to do.

Basically it involved removing bricks along the bottom of the wall, removing bricks at the top, and feeding compressed airlines in at the top and vacuum pipe at the bottom.

You have to blow it down the cavity and suck it out in a controlled manner.

And if it's the foam type, same idea but you pump a solvent into the top of the wall and and remove the waste from the bottom.



Leeds-20120322-00286.jpg
 
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baboboy

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I've taken it out of a very large house and it is a hell of a job to do.

Basically it involved removing bricks along the bottom of the wall, removing bricks at the top, and feeding compressed airlines in at the top and vacuum pipe at the bottom.

You have to blow it down the cavity and suck it out in a controlled manner.

And if it's the foam type, same idea but you pump a solvent into the top of the wall and and remove the waste from the bottom.
Also sounds expensive. Lol.

Will probably see if what we’ve done this year has made any difference.
 

mickthechippy

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A lot of houses had cavity fill fitted under the cheap government scheme

many of them had totally unsuitable insulation fitted from brown mica-fill in pellet and threads form to blown foams insulation,

it was a case of a scramble for the customer base at the time

whilst the roof spaces, were more often filled with standard stuff and that was eminently suitable for purpose, the wall fill was often wrong and led to damp and breathing problems,

I do believe there is some sort of agency dealing with the problem now and they can survey the fill and give their report on it, suitable or not as the case may be

its then sent back to the installation companies for remediation
 

Dave

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The problem with a lot of the early blown-wool type is it was okay when first put in but eventually sags and sits in clumps on top of wall ties.
This causes condensation to gather in the cavity where the insulation is no more and when it runs down the cavity it soaks into the clumps forming damp spots. Not only that but it rots the wall ties.
 
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