What to board on new bathroom floor prior to tiles ?
Discussion
Hi All
Just about to get my bathroom refurbished. Whole lot is coming out, and new suite and tiles etc going on.
The floor and the joists will be re-inforced to ensure that it is as stable as possible, as we have got tiles cracking on the floor currently ?previous poor installation, not sure, but this time round we don't want it to happen. House is only 10 years old, and otherwise built pretty well.
I am getting very confused. The bathroom person will be taking all the floor up, and then putting down new board. But should it be hardibacker, no more ply, ditra mat ? What thickness of the board should we use ?
What should go under the shower tray ? The same board ? or something different. The last shower tray starting to leak around the tiles, and into the kitchen, so dont really want that again.
Should the shower tray be bedded down onto cement ? Or glued down ?
Sorry for all the questions !
R
mehul
Just about to get my bathroom refurbished. Whole lot is coming out, and new suite and tiles etc going on.
The floor and the joists will be re-inforced to ensure that it is as stable as possible, as we have got tiles cracking on the floor currently ?previous poor installation, not sure, but this time round we don't want it to happen. House is only 10 years old, and otherwise built pretty well.
I am getting very confused. The bathroom person will be taking all the floor up, and then putting down new board. But should it be hardibacker, no more ply, ditra mat ? What thickness of the board should we use ?
What should go under the shower tray ? The same board ? or something different. The last shower tray starting to leak around the tiles, and into the kitchen, so dont really want that again.
Should the shower tray be bedded down onto cement ? Or glued down ?
Sorry for all the questions !
R
mehul
If your worried about the tray leaking use one with a tile upstand or use this https://www.rubberduckbathrooms.co.uk/classi-seal-...
Use a decent 9/12mm ply on the floor or hardibacker if you want to keep the height to a minimum.
Make sure the tiler uses good quality adhesive (flexible for the floor) and good grout, this is the first line of defence, get that right and whatever is under the tiles becomes immaterial.
Use a decent 9/12mm ply on the floor or hardibacker if you want to keep the height to a minimum.
Make sure the tiler uses good quality adhesive (flexible for the floor) and good grout, this is the first line of defence, get that right and whatever is under the tiles becomes immaterial.
Mehul9216 said:
Hi Ashtray - thanks for the advice - what do you mean by "putting perimeter noggins and noggins on any joins" - just want to make sure that the builder does what I tell him to, and that I look as if I know what I am talking about ! Do you mean on the joists ?
R
Mehul
Basically a noggin is a bit of wood perpendicular to and between the joists connecting two of them together. Google will show you pictures!R
Mehul
In this case they would be positioned such that the sheets of ply or whatever are supported at their edges and also at any point where two sheets butt against each other. It reduces the scope for flex.
So noggins would go at two edges of the room and also in a line anywhere in the middle of the room where there's a sheet joint.
At least that's my understanding.
I had the same concerns.
Ended up going for a vinyl floor made by QuickStep.
The stuff is brilliant. Looks like a tile, feels like a tile but no risk of cracking and it's much warmer. Wouldn't bother trying to tile a non concrete/hard floor again now I've seen how good laminate/vinyl flooring can be these days.
It is more limited in the respect that there isn't as much option on finishes as there are with tiles and obviously if you are going for UFH then a tile would be more suitable.
I recommend you have a look, if you haven't already.
Ended up going for a vinyl floor made by QuickStep.
The stuff is brilliant. Looks like a tile, feels like a tile but no risk of cracking and it's much warmer. Wouldn't bother trying to tile a non concrete/hard floor again now I've seen how good laminate/vinyl flooring can be these days.
It is more limited in the respect that there isn't as much option on finishes as there are with tiles and obviously if you are going for UFH then a tile would be more suitable.
I recommend you have a look, if you haven't already.
I used Marmox boards for my installs. Whilst these are concrete faced like aqua panel, they do not allow the passage of water. The problem with aqua panel and WBP is that whilst they do not degrade , they will allow the passage of water and will wick up moisture.A barrier membrane is often recommended with aqua panel to prevent the passage of moisture.
I went through this a while ago. There doesn't really seem to be a consensus.
A lot depends on how much height you can get away with in the floor - you don't want a stupid little step up into the bathroom.
You basically want it not to move . The places that it's most likely to move are the joints between the boards. Noggins between all the joints as mentioned previously are a good idea but it takes time and it's sometimes not possible with pipework etc.
If it's a 10 year old house then you probably have 22mm tongue and groove chipboard throughout the rest of upstairs. If it's been getting wet for a time then it's probably knackered and worth replacing. You can use 22mm green (water resistant)T&G chipboard with noggins at all joints and glued joints. That will give you a pretty decent base at the same height as the neighbouring room, but you will need to either use a decoupling membrane/mat ( eg Ditra or electric underfloor heating decoupling mat) or v. good adhesive. Mapei do a specific one for this. You will need to use the appropriate primer / sealer on the chipboard for the adhesive, not just PVA. It may want the sealer underneath as well.
Depending on the shower tray you choose it may specify that it must be installed on a single piece of specified thickness ply, and will state what it needs to be bedded on, you should install as specified, and know how it needs to be done before starting the rest. The last thing you want is to have to start again as the shower's leaking.
You can alternatively use ply throughout for the floor, minimum 18mm better 25mm but it tends not to be T&G which potentially offers less stability at joints, though shouldn't be an issue if fitted and glued well. Ply is more inherently water resistant than chipboard but neither should be getting wet anyway. Some people will suggest marine ply, most think that the cheaper WBP ply is plenty water resistant.
Hardibacker is another alternative but I think it adds to the height so I haven't used it.
Any decent builder should be able make this work without issue, he will likely have a set way that he always does it, and that works for him. I would be inclined to take his advice and just post up what he has said he will do for comment if you have any concerns.
I'm not a builder, just my experiences from DIYing a few bathrooms, so will happily be corrected.
A lot depends on how much height you can get away with in the floor - you don't want a stupid little step up into the bathroom.
You basically want it not to move . The places that it's most likely to move are the joints between the boards. Noggins between all the joints as mentioned previously are a good idea but it takes time and it's sometimes not possible with pipework etc.
If it's a 10 year old house then you probably have 22mm tongue and groove chipboard throughout the rest of upstairs. If it's been getting wet for a time then it's probably knackered and worth replacing. You can use 22mm green (water resistant)T&G chipboard with noggins at all joints and glued joints. That will give you a pretty decent base at the same height as the neighbouring room, but you will need to either use a decoupling membrane/mat ( eg Ditra or electric underfloor heating decoupling mat) or v. good adhesive. Mapei do a specific one for this. You will need to use the appropriate primer / sealer on the chipboard for the adhesive, not just PVA. It may want the sealer underneath as well.
Depending on the shower tray you choose it may specify that it must be installed on a single piece of specified thickness ply, and will state what it needs to be bedded on, you should install as specified, and know how it needs to be done before starting the rest. The last thing you want is to have to start again as the shower's leaking.
You can alternatively use ply throughout for the floor, minimum 18mm better 25mm but it tends not to be T&G which potentially offers less stability at joints, though shouldn't be an issue if fitted and glued well. Ply is more inherently water resistant than chipboard but neither should be getting wet anyway. Some people will suggest marine ply, most think that the cheaper WBP ply is plenty water resistant.
Hardibacker is another alternative but I think it adds to the height so I haven't used it.
Any decent builder should be able make this work without issue, he will likely have a set way that he always does it, and that works for him. I would be inclined to take his advice and just post up what he has said he will do for comment if you have any concerns.
I'm not a builder, just my experiences from DIYing a few bathrooms, so will happily be corrected.
As you are having the floor up and beefing up the joists then a well installed chipboard (22mm) floor is more than sufficient, it's all moisture resistant now. There's several adhesives for this flooring. Prime as per manufacturers recommendation. If your fitter is good he'd get the tray rock solid bonding it with (board not full fat expanding) foam, can't say I know of anyone else that does this but it's never failed with us. Generous bead of sealant to the wall.
Don't need ditramat. If electric ufh then cover with self leveling and prime again prior to tiling.
Don't need ditramat. If electric ufh then cover with self leveling and prime again prior to tiling.
Mehul9216 said:
Hi All
Just about to get my bathroom refurbished. Whole lot is coming out, and new suite and tiles etc going on.
The floor and the joists will be re-inforced to ensure that it is as stable as possible, as we have got tiles cracking on the floor currently ?previous poor installation, not sure, but this time round we don't want it to happen. House is only 10 years old, and otherwise built pretty well.
I am getting very confused. The bathroom person will be taking all the floor up, and then putting down new board. But should it be hardibacker, no more ply, ditra mat ? What thickness of the board should we use ?
What should go under the shower tray ? The same board ? or something different. The last shower tray starting to leak around the tiles, and into the kitchen, so dont really want that again.
Should the shower tray be bedded down onto cement ? Or glued down ?
Sorry for all the questions !
R
mehul
If you are having this done, then I would go with whichever product your installer / tiler recommends and therefore guarantee's. Hardibacker, No More Ply , Ditra are all good products. Just about to get my bathroom refurbished. Whole lot is coming out, and new suite and tiles etc going on.
The floor and the joists will be re-inforced to ensure that it is as stable as possible, as we have got tiles cracking on the floor currently ?previous poor installation, not sure, but this time round we don't want it to happen. House is only 10 years old, and otherwise built pretty well.
I am getting very confused. The bathroom person will be taking all the floor up, and then putting down new board. But should it be hardibacker, no more ply, ditra mat ? What thickness of the board should we use ?
What should go under the shower tray ? The same board ? or something different. The last shower tray starting to leak around the tiles, and into the kitchen, so dont really want that again.
Should the shower tray be bedded down onto cement ? Or glued down ?
Sorry for all the questions !
R
mehul
We use No more ply for the floor, either, 6 or 9mm dependant upon how solid the floor is. (A normal sized bathroom with 22mm floor boards, usually 6mm will be enough).
If there is Plasterbaord in a shower zone, then this would be replaced with 12mm Hardibacker.
The tray should be installed in accordance with the. Manufacturers instructions. Some need to be fully bedded, some don't.
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