Plaster onto Damp Wall??

[Steve2M]

Just interested on any thoughts on the following:-
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During building work on side extension, there was a long period when the new, insulation-filled outside cavity wall was exposed to the elements.
We had a few days of REALLY heavy rain a few weeks ago, and, just after this, the wall plates/roof added, thus probably sealing in the saturated insulation.
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One section of the wall was particularly drenched, as the down-pipe from the whole of the roof of the upper floor effectively poured all this water into the cavity.
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Three weeks later, the inside block-work for this section (approx 8 feet) is still dark in colour, and cold/damp to touch.
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I am convinced that the insulation is still really saturated, yet we are just about to have it plastered.-
Do I need to be concerned?
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The builder is well-established/professional, and very relaxed about this issue, telling me my worries are unfounded, and it will just dry out in time.
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Please shout if you have any views.
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Many Tks, Steve

 

[noseall]

It will dry out eventually.

There may be some contraction cracking and a bit of efflorescence though this may not become evident if the finish is going to be d&d.

 

[mointainwalker]

I have no direct experience of this, but i don't see how saturated insulation in a sealed cavity will ever dry out .

Noseall, is your "eventually" measured in months or years ?

 

[Steve2M]

Tks for your comments.
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D&d....presume you mean plasterboard... if so, then this will not be the case. they will be plastering direct to block-work.
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What makes this worse, is that it is in the kitchen area, so, eventually will need "kitchen and bathroom" type paint, which will probably restrict the drying out process even further.
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I just cannot see how the plaster has a hope in hell of drying, if it is being permanently wetted from the inside.
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Wife+Kids think I worry/analyse things too much.... maybe they're right???
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Steve

 

[freddiemercurystwin]

Its not ideal but comfort yourself with the fact that thousands of houses are built every year where the insulation etc gets a good soaking and the the walls are plastered up, they generally don't suffer from damp problems.

 

[mointainwalker]

Wife+Kids think I worry/analyse things too much.... maybe they're right???

Not sure in this case, but my own experience - and that of lots of posters on this site - is that some builders will tell you any old rubbish to try to avoid having to correct sloppy work/botches.

To the professionals on here, are there recognised codes of practice (established by prof. bodies/ NHBC etc ) covering things like this that should be adhered to ?

 

[noseall]

It WILL dry out because it would need a source of water to stay wet.

The worst case scenario may be some efflorescence on the plaster. If this is not acceptable then try and encourage the builder to leave this wall 'till last, but i would say that within a week or so the wall will be nearly there.

 

[noseall]

Oh, by the way, some plasterers soak the wall with a hose prior to plastering a wall.

 

[Richard C]

What makes this worse, is that it is in the kitchen area, so, eventually will need "kitchen and bathroom" type paint, which will probably restrict the drying out process even further.

If you ever buy a new house (& I’ve had 2), you will/should be told not to decorate with Vinyl/waterproof paint or wallpaper for at least 6 months in order for the residual moisture to escape from the building fabric; decorate initially with plain old matt emulsion.

IMO the bathroom/kitchen stuff is grossly over rated anyway & I’ve never used it. I’ve always stuck with bog standard matt emulsion & never had any problems; providing good ventilation is the key.