18mm ply for tiling - but theres lots of types! Help!

[paolow]

Apologies for such a banal question (and I have put my hall joists on hold for now) but I want my (small) bathroom to have tiles so of course first I must fit a stable base.
Ok - 18mm ply is the recognised standard (some would say some form of backerboard etc - but I am happy with ply) but now I am a bit stuck.
I'm stuck because the choices seem to boil down to either 18mm hardboard or 18mm WBP board (softwood) and I don't really know which one is preferable. On the face of it the hardboard offers a greater level of rigidity, though the softwood WBP of course has another element of waterproofness which, for a bathroom could be desirable.
I'm a bit stuck as I need to order tomorrow AM to get it for Friday so would appreciate some advice! Ive been all over the internet but there are some very conflicting reports so I am back to square one really :/
At the moment I am thinking of getting the hardboard because if the tiles/grout fail the board will end up toast sooner or later anyway and the rigidity it offers should guard more strongly against the tiles/grout failing in the first place.
Is that a wrong train of thought?
I am a little limited by needing really to use Travis Perkins http://www.travisperkins.co.uk/c/timber-sheet-mate... as I also need some tapered edge plasterboard and it would be handy for lots of reasons to have the lot delivered at once - but I would hate to go through the aggravation of screwing down the wrong sort of ply. Can anyone help?

[singlecoil]

When you say hardboard do you mean hardwood, as in hardwood ply?

Hardboard is a compressed fibre material with one shiny face, and is usually on a few mm. thick.

[p1stonhead]

Use a cement board like Hardiebacker on wall, 18mm WBP on floors. Ditra matting is also a good idea if the tiles are particularly large.

Edited by p1stonhead on Wednesday 11th March 18:30

[moustachebandit]

paolow said:

Apologies for such a banal question (and I have put my hall joists on hold for now) but I want my (small) bathroom to have tiles so of course first I must fit a stable base.
Ok - 18mm ply is the recognised standard (some would say some form of backerboard etc - but I am happy with ply) but now I am a bit stuck.
I'm stuck because the choices seem to boil down to either 18mm hardboard or 18mm WBP board (softwood) and I don't really know which one is preferable. On the face of it the hardboard offers a greater level of rigidity, though the softwood WBP of course has another element of waterproofness which, for a bathroom could be desirable.
I'm a bit stuck as I need to order tomorrow AM to get it for Friday so would appreciate some advice! Ive been all over the internet but there are some very conflicting reports so I am back to square one really :/
At the moment I am thinking of getting the hardboard because if the tiles/grout fail the board will end up toast sooner or later anyway and the rigidity it offers should guard more strongly against the tiles/grout failing in the first place.
Is that a wrong train of thought?
I am a little limited by needing really to use Travis Perkins http://www.travisperkins.co.uk/c/timber-sheet-mate... as I also need some tapered edge plasterboard and it would be handy for lots of reasons to have the lot delivered at once - but I would hate to go through the aggravation of screwing down the wrong sort of ply. Can anyone help?

If you don't have a floorbase have you considered using 18mm OSB for the floor and then just overlaying with a thin layer of ply for tiling purposes?

TBH whether its softwood, hardwood Ply or OSB it really makes no odds - water will ruin all of them over time, BUT water should never get to them if you do the job properly. If you have a walk in shower / wet room affair then you should also look at tanking kits to provide some extra protection.

Why do you need to use TP - is it due to delivery reasons? If so then try Jewson, they also deliver and depending on how far away you are can be as little as £5.

[wolfracesonic]

If you have got your heart set on using ply from TP I'd probably use this one 18mm ply Use 25mm if you are going direct on to the joists, plenty of screws either way. Prime it with Bal prime at the very least or better still use a tanking kit, they're not that expensive and not as daunting to use as they sound. Bal primers, waterproofing

[Pheo]

Is this replacing floorboards? If so, I would go 22mm thick WBP ply as a base. Mother in law just had it done. We have 12.5mm ply over floorboards, and then ditra mat over that as well.

[paolow]

Sorry - I should have got it right when explaining:

Yes I do mean a hardwood ply - not hardboard - I hate hardboard as the guy that used to live here used it for EVERYTHING I wanted to keep and retain but can't because its not fit for the purposes he intended! I must have it on the brain!

Also the ply will be screwed to existing floorboards (which are tatty due to being cut for electrics etc but are otherwise ok - not rotten in the slightest and screwed down tight)
I would have liked to take up the lot but that isn't practical due to new partition walls etc so overboarding it is.

I am an absolute BAL convert and will be using this without question on this bathroom which includes sealing the floor before going down the tiling route. I may yet choose another option - but for now if I make it good enough for tiles then in theory I can lay what I want (I think) in the future.

[paolow]

paolow said:

Sorry - I should have got it right when explaining:

Yes I do mean a hardwood ply - not hardboard - I hate hardboard as the guy that used to live here used it for EVERYTHING I wanted to keep and retain but can't because its not fit for the purposes he intended! I must have it on the brain!

Also the ply will be screwed to existing floorboards (which are tatty due to being cut for electrics etc but are otherwise ok - not rotten in the slightest and screwed down tight)
I would have liked to take up the lot but that isn't practical due to new partition walls etc so overboarding it is.

I am an absolute BAL convert and will be using this without question on this bathroom which includes sealing the floor before going down the tiling route. I may yet choose another option - but for now if I make it good enough for tiles then in theory I can lay what I want (I think) in the future.

Also - I have just spotted that we have a jewson in Eastbourne too - so thanks for the heads up! Will explore that now....

[paolow]

Have checked Jewson - so that avenue is avaialble too! hooray! But there is spruce, coniferous and the somewhat ambiguous 'far eastern' ply if I go the soft route. Who would have thought there would be so many types!

[Pheo]

paolow said:

Have checked Jewson - so that avenue is avaialble too! hooray! But there is spruce, coniferous and the somewhat ambiguous 'far eastern' ply if I go the soft route. Who would have thought there would be so many types!

Quality of the timber.

One thing to be aware of - if you are not using T&G flooring ply, then you need to noggin in between the joists on the joins.

[Neil - YVM]

paolow said:

Sorry - I should have got it right when explaining:

Yes I do mean a hardwood ply - not hardboard - I hate hardboard as the guy that used to live here used it for EVERYTHING I wanted to keep and retain but can't because its not fit for the purposes he intended! I must have it on the brain!

Also the ply will be screwed to existing floorboards (which are tatty due to being cut for electrics etc but are otherwise ok - not rotten in the slightest and screwed down tight)
I would have liked to take up the lot but that isn't practical due to new partition walls etc so overboarding it is.

I am an absolute BAL convert and will be using this without question on this bathroom which includes sealing the floor before going down the tiling route. I may yet choose another option - but for now if I make it good enough for tiles then in theory I can lay what I want (I think) in the future.

18mm ply over original floorboards will be solid, but will raise the level quite a bit.

Tile backing board like Hardibacker or No More Ply will give a better surface to tile on, without the height build up.

9mm backing board over original flooring is very stable.

[Spudler]

Take whole floor up.
22mm T&G flooring glued & screwed to joists & t&g.
Prime.
Latex IF electric ufh.
Bal Rapid Flex.

[paolow]

Sigh - so yesterday I firmly ended up at square one which included a friendly, humour filled and light hearted chat with Mrs Paolow about the whole thing.
The trouble is that I absolutely DO NOT want a big step up into the bathroom, which, of course is exactly what I will end up with by overboarding. I HAD always wanted to take up the tatty floorboards and whack new ply onto the joists but the snag with that is that two of the walls are built onto the old boards. however - where this is the biggest problem is where the bath would go so I suppose I could just keep them terminating on the first joist in the bathroom and run the new ply to them out of sight...
FFS - nothing is easy....
Ill get the boards up again tonight / tomorrow and consider it again - and a story is always better with pictures - Ill see about getting some so things are clear....

[Boarder1]

Spruce plywood, 18mm, grade II/III if available, CE2+, ideal for all structural applications.

Also, please don't assume WBP means the whole panel is waterproof, it merely means the glue line can handle 72hrs of boiling and is designed for exterior use and should not deteriorate due the elements of weather! The wood itself still needs some form of protection.

A lot of plywood these days is reinforced melamine glue, which should quite easily handle 6hrs boiling and covered exterior use, but definitely enough for indoor use.

Avoid Chinese product, it may be cheap but not worth the hassle!

Stick with the spruce!

[paulrockliffe]

I replaced all my floorboards with 22mm Egger chipboard, including in the bathroom. I had issues with two stud walls that were sat on the existing floor boards, I was able to fit new boards under one as all the plaster was removed so it was light enough to ease them under. For the other one I set the circular saw blade to the right depth to curt the boards, but not the joists and ran it up the middle of the joists either side of the wall, avoiding the nails of course. I then laid the new floor up to this and filled and blended using a PVA and sawdust mix, to make sure no lines appeared in the carpet.

I laid 12mm ply over the chipboard in the bathroom, screwed at 300mm spacings and then tiled (60 x 60) over this using a flexible adhesive. No issues at all and there's no way water is going to get through to the floor.

[Harry H]

Neil - YVM said:

18mm ply over original floorboards will be solid, but will raise the level quite a bit.

Tile backing board like Hardibacker or No More Ply will give a better surface to tile on, without the height build up.

9mm backing board over original flooring is very stable.

This bloke has already given you the answer. Hardibacker is designed for exactly what you want to do. Jewsons sell it.

[stanwan]

If you are going to do it properly try the proper swedish way-

22mm moisture resistant chipboard and then self levelling compound with 2.5 mm steel mesh. This will give a rock solid impervious floor that you can tank with a fleece membrane like schluter kerdi/kerdi DS.

[paolow]

Firstly thanks so much for all of the above - I have taken some pics that hopefully do a better job of showing things than my description!

So here is an overview of what we are looking at....



Here is the crux of the matter - what was one room has been split into two with a breezeblock wall where the wall sits on the edge of one joist and would be unsupported if I tried getting rid of all the current boards.....



And in other places too the old boards disappear under another part of wall.....




Ideally I would take up the boards and lay new 22mm ply which would be a FAR better floor for my purposes than the current hotch potch of boards. I could then go with backer board onto the ply etc if be need be. But is there a straightforward way to do that? would I just leave the boards across the joists where it cannot be removed and then ply to it? Or is that not the right idea either? I'm starting to get a bit outside my comfort zome with this - but can stay within it if there is a relatively easy solution? I'm really stuck as of course nothing can happen with the bathroom until the floor is done :/

[Neil - YVM]

Harry H said:

Neil - YVM said:

18mm ply over original floorboards will be solid, but will raise the level quite a bit.

Tile backing board like Hardibacker or No More Ply will give a better surface to tile on, without the height build up.

9mm backing board over original flooring is very stable.

This bloke has already given you the answer. Hardibacker is designed for exactly what you want to do. Jewsons sell it.

This is still the correct answer.

[CoolHands]

imo you should keep all original floorboards as is, and use hardiebacker(? Sp) or nomoreply as mentioned above. You seem to be overcompliczting it. (unless this is wetroom and I've missed that?)