Bathroom tiling - TilersForums.co.uk | Tile Forums

23-03-2008

I have a two fold question:
Is it stipulated in building regs that you have to use water resistant plasterboard in a bathroom?
If ordinary plasterboard is used, sealed correctly and tiled over with waterproof adhesive and grout, what is the proabability of water getting behind the tiles and damaging the plasterboard inside a shower enclosure? What time period would you expect this to happen over?
Thanks for your help.

**sibs** · 23-03-2008

Firstly, there is no such thing as waterproof adhesive or grout unless it is "epoxy" grout. Standard adhesives and grouts once set,will not break down in the presence of water but water will still soak into them and may damage the plasterboard underneath over a period of time, although the good quality flexible ones will be more effective at slowing the rate of water absorption down.Ordinary plasterboards can be used in a shower area as long as it is tanked before being tiled onto or your other option is to use tile backerboard which is cement based and is impervious to water. You just have to make sure all the joints are waterproofed. Hope this helps

**whitebeam** · 23-03-2008

I've worked on site and they don't use moisture resistant plasterboard, If your using plasterboard why not aqua or hardie backer board, making sure the boards are fixed well so no movement. I like superflex grout by bal, If water penetrates into the gypsum board it will happen a time just all depends wether your've got a power shower or standard one, Tank the plasterboard with bal WP1 you should'nt have any problems and silicone well into the area's of the shower enclosure

**Dave** · 23-03-2008

Also using a water proofing membrane is quicker than a tanking kit and can be tiled on straight away..........

Kerdi mat and homelux membranes are just a couple of them available

**grumpygrouter** · 23-03-2008

Quote:

Originally Posted by sibs

Firstly, there is no such thing as waterproof adhesive or grout unless it is "epoxy" grout. Standard adhesives and grouts once set,will not break down in the presence of water but water will still soak into them and may damage the plasterboard underneath over a period of time, although the good quality flexible ones will be more effective at slowing the rate of water absorption down.Ordinary plasterboards can be used in a shower area as long as it is tanked before being tiled onto or your other option is to use tile backerboard which is cement based and is impervious to water. You just have to make sure all the joints are waterproofed. Hope this helps

Good answer Sibs!

Grumpy

**sibs** · 23-03-2008

Thanks Grumps we'll make a tiler out of me yet!

**Sir Ramic** · 23-03-2008

Oh dear i may not win many fans for this but.
Firstly, there is no such thing as waterproof adhesive or grout unless it is "epoxy" grout. Standard adhesives and grouts once set,will not break down in the presence of water but water will still soak into them and may damage the plasterboard underneath over a period of time, although the good quality flexible ones will be more effective at slowing the rate of water absorption down.
I agree.

Ordinary plasterboards can be used in a shower area as long as it is tanked before being tiled onto or your other option is to use tile backerboard which is cement based and is impervious to water. You just have to make sure all the joints are waterproofed. Hope this helps

Not true..Ordinary plasterboard may be used and it is all the time in new builds as there is no building spec to say otherwise (none that i am aware of anyway).
There is nothing to say it should be tanked either.
I know what you are trying to say and yes..if you want to make the shower area waterproof then that is the option but it is only an option.
In all my years of tiling i have only tanked out 2 rooms and used backerboards on a few too.
I would hope in the coming years it will become compulsary but as yet it isnt.

**grumpygrouter** · 23-03-2008

Quote:

Originally Posted by Sir Ramic

Oh dear i may not win many fans for this but.
Firstly, there is no such thing as waterproof adhesive or grout unless it is "epoxy" grout. Standard adhesives and grouts once set,will not break down in the presence of water but water will still soak into them and may damage the plasterboard underneath over a period of time, although the good quality flexible ones will be more effective at slowing the rate of water absorption down.
I agree.

Ordinary plasterboards can be used in a shower area as long as it is tanked before being tiled onto or your other option is to use tile backerboard which is cement based and is impervious to water. You just have to make sure all the joints are waterproofed. Hope this helps

Not true..Ordinary plasterboard may be used and it is all the time in new builds as there is no building spec to say otherwise (none that i am aware of anyway).
There is nothing to say it should be tanked either.
I know what you are trying to say and yes..if you want to make the shower area waterproof then that is the option but it is only an option.
In all my years of tiling i have only tanked out 2 rooms and used backerboards on a few too.
I would hope in the coming years it will become compulsary but as yet it isnt.

That was the crux of the original question Sir Ramic, he wanted to know if water got behind the tiles how long it would be before he had problems.

Sibs' answer pointed him in the direction to eliminate the problem all together - if done correctly - but i believe you are right there is no regulation that areas need to be waterproofed, maybe it should. She didn't tell him how quickly it might fail, which was actually his question.

I believe, and I was instructed this way, that training schools are now teaching that it is always to suggest to customers that tanking is a good idea in areas where it may be necessary. I know most people are not interested in the additional cost of this but then the onus goes onto them if problems arise in the future.

Out of interest, I will be doing my 2nd tanking job in a couple of weeks and I am just coming up to the end of my first full year in business I have also used Aquapanel on one job. Some people do listen and understand the reasoning, and there are some that are not bothered.

Grumps

**Sir Ramic** · 23-03-2008

I dont disagree with you at all Grumpy. I wish all rooms were tanked after all that would mean more work and money for me

...as you say though some people dont listen and money is the key factor.
If ever i have tried to push the tanking route i have been asked how many of my untanked jobs have had problems... i cant honestly remember one that had issues with what we are talking about here....So if i tell the client that ,they cant see why the tanking and maybe presume i am trying to sell them something they dont need....... What can i do, after all i am only the tiler.

wall2floortilin · 23-03-2008

i manage sites as well as having my own tiling company, there are no regs under buiding controls for using standard plasterboards in shower applications.
providing you prime bare plasterboard with acrylic, double seal plaster joints with silicone you wont have a problem.

**sibs** · 23-03-2008

Hi SirRamic ....
Not sure what you're dissagreeing with.... I didn't say those were the rules more trying to point him in the direction of best practice. I really don't know what building regs state with regard to materials and weather or not wet areas "must" be tanked but I was taught that it is ok to use plasterboard in wet areas as long as you tank it... especially with power showers.Again best practice not regs.... so we seem to be agreeing as far as I can tell.

**Sir Ramic** · 23-03-2008

What i disagree with is a comment you made
"Ordinary plasterboards can be used in a shower area as long as it is tanked before being tiled onto"
Which is not true as ordinary plasterboard can be used and generally it is.
Your comment seems to implies that you can only use plasterboard if its tanked.

Also if you read my posts i do agree with the practice of tanking its just that in a real world the public dont as it costs them money. Bring it on i say.