Am I right that once ordinary plasterboard gets wet it loses all its strength and will never regain it once dried out?

My council / building works issues part 497. To cut a long ( 14 year dispute) story short they have again made a mess of my roof, allowed water in to the building which has obviously wet the plasterboard in my bathroom behind the tiles. Its fully plastered and tanked on the inside and has insulation with a foil layer on the outside but water will have been soaking into the top edge. IMO the only repair is to strip the wall right back to the studs and reboard, replaster, retank and retile. At the moment surely the tiles are holding the plasterboard in place. ?The bathroom has been inplace less than two years

Opinions please?

You are correct and it will harbour mould.

The plasterboard will tend to ‘blow’ where it expands when wet, too.

Ta chaps. I thought so

You know its one thing I have to thank STW for. My terrier like debating skills which I honed on here have been very handy so far in this dispute with the council 😉

Use cement board or, at least, the green (water resistant) plasterboard for the bathroom. Although this won’t help the current situations or any other rooms that are affected by a leaky roof!

Sam – it was fully plastered and tanked and the roof had just been completely redone. There really shouldn’t have been any water getting in – but in general I would agree

Replace

If it’s been leaking for some time, then you have an issue. With it being behind tiles, then it’s not going to dry.

We’ve had a few leaks over the years but they have been short term, we were able to dry out affected lounge ceiling. We’ve had a bath leak and a toilet mains inlet leak.

My terrier like debating skills

aw oh, this ain’t going to end well! 😆

Use cement board or, at least, the green (water resistant) plasterboard for the bathroom

agree on the tilebacker board but moisture resistant plasterboard is not really any more suitable for a bathroom than normal plasterboard. it would still need tanking.
best not to skim plasterboard when its being tiled over, all it does is lower the weight limit for tiles. just tank straight onto the plasterboard in wet areas but again tilebacker boards are much better.

Best not to skim new plasterboard anytime, it’s a pointless exercise.

I assume you mean for Tiling over Because it looks pretty naff when its only painted.

My terrier like debating skills

Yapping incessantly and then peeing up your leg.

My terrier like debating skills

Can you get banned from communicating with the council?
🙂

I assume you mean for Tiling over Because it looks pretty naff when its only painted.

Don’t think so, looks just fine when done properly plus you don’t get bits of plaster cracking all over the place in future.

House built in 1992 was boarded and skimmed and has been perfect ever since. As ever only as good as the person doing the job

agree on the tilebacker board but moisture resistant plasterboard is not really any more suitable for a bathroom than normal plasterboard. it would still need tanking.
best not to skim plasterboard when its being tiled over, all it does is lower the weight limit for tiles. just tank straight onto the plasterboard in wet areas but again tilebacker boards are much better.

What a load of bollox

whats bollox and if you think it is you obviously haven’t got a clue about tiling

“Edited again because I just can’t be arsed!

moisture resistant plasterboard is not really any more suitable for a bathroom than normal plasterboard. it would still need tanking.

Moisture-resistant (MR) plasterboard is produced especially for bathrooms and kitchens, and it doesn’t need tanking. You can use it outside in protected locations, a ceiling in a doorway, some soffits,etc

best not to skim plasterboard when its being tiled over, all it does is lower the weight limit for tiles

Skimming with a gypsum-based plaster defeats the point of MR boards, however, there are circumstances where MR boards might be used and then skimmed in a dry environment (but not tiled)

Awaits a flaming from wrightyson 🙂

Whenever I’ve refurbished a bathroom I’ve found the plasterboard behind the tiles to be a soggy mess. But that’s usually because the tiling was done with dot & dab and non-showerproof grout.

I can’t help thinking that if the water ingress is eliminated, and there’s enough air circulation to allow the affected plasterboard to dry out then there isn’t going to be much of a problem. Unless the wall has developed a bit of flex.

Not from me timba. What you state is fair I’d say.
To suggest plasterboard should not be used in bathrooms however would pretty much outlaw a lot of new builds.

i never said it shouldn’t be used in bathrooms, maybe i should of said MR is no better than normal board rather than suitable. any plasterboard in a bathroom needs tanking in wet areas so its much better to use a fully waterproof tilebacker board instead if possible.

i have had to skim onto MR boards before, they are meant to have a coat of Bond-it on first to provide a key but the customer wouldn’t pay for it so it got skimmed without at his risk, was a few years ago now and i’ve never heard of any problems with it.

bigjohn unless epoxy grout is used all grout can let moisture through and can take a while to dry out especially in a heavyly used shower, i wouldn’t recommend using epoxy though.

mentioning new builds doesn’t mean much with the standards most are built to nowadays.