Plasterboard problem

[Stephen H]

Hi all,

I bought a house last December where there is plasterboard internally on the external walls. (the internal walls have plastering on them).

The house was built 25 years ago and whoever fitted the plasterboards did not fix the edges very well or put in scrim tape. There is cracks in the skim where the plasterboard sheet edges meet up.

This means that when you place your hand on either side of the skin crack lines, the plasterboard can be made to flex a bit.

I got talking to a surveyor and he has suggested that rather than take all the plasterboard off and installing new plasterboard, fitting scrim tape and re-skimming, I should drill a series of holes along the crack line, inject expanding foam and then fill the holes and the crackline in with polyfiller. He claims that this will stabilise the two plasterboard sheets and prevent reappearance of the crack lines.

What do the panel think?

Stephen.

[Bill]

In message , Stephen H writes

I'm sure that others will come along who have had experience of this, but my thoughts would be to find a low expansion foam and don't use too much of it. There have been a few horror stories of expanding foam continuing to expand and causing damage, It could be embarrassing if it pushed your board off the wall. I recall a photo of a canoe something along the lines of they used it to fill a buoyancy void and it split it apart.

If no one says it is a really stupid idea though, I will put it on my list of useful work around's.

[Alan]

In message , Bill wrote

[brass monkey]

Brilliant, just brilliant :D

[RustyCrampon]

I recently injected about 10 cans of expanding foam through plasterboard into a flimsy partitiion wall to make it more sturdy, and stop the microbore pipes inside it rattling around. It seems to have worked.

I used standard expanding foam, but I only injected one can at a time, and waited at least an hour for each injection to stop expanding before the next injection. IIRC, a 750ml can of Screwfix No-Nonsense foam will expand to about 35 litres before setting.

[Lobster]

I think it could or would work brilliantly, but only if you got exactly the right amount of foam in there - would be hard to estimate how much you need and there would be a high probability of ending up with bulging walls instead.

If you go ahead, keep the injected amounts really small and give it plenty of time to cure; eg maybe drill a series of holes three feet(?) apart along the cracks, inject those, and then later on repeat the process with a second set of holes drilled in the gaps between the first set.

David

[the_constructor]

This anygood for you ?

G

[geraldthehamster]

Indeed. Large volumes of foam squirted at once tend to result in horribly sticky voids within, that don't go off.

Cheers Richard