Tiling a bathroom floor ply wood size??

ossm145 · Post by **ossm145** » Mon Mar 31, 2014 11:55 pm

Hello

I am about to have my bathroom tiled and the tiler said to install 5.5mm plywood ?

No I have just taken up the old floorboards and replaced with t & G white wood 18mm on joist 500mm apart. which i used spax floorboard screws 2 to each joist

Can you please advise if wbp 5.5mm is ok

Colour Republic · Post by **Colour Republic** » Tue Apr 01, 2014 12:31 am

No sadly not

According to British Standards 15mm is the minimum but seeing as 18mm is much easier to get hold of, most tilers use that.

4/5/6mm ply is too thin, it is likely to have movement and air pockets under, it is also much more likely to delaminate with the moisture from the tile adhesive, no good as a solid sub base. You could have laid 18mm ply directly on the the joists and tiled that (personally I would go for 22 or 25mm if doing that) But seeing as you have already replaced the floor, and you would have an issue with floor height if you overboarded with 18mm ply, then the better option is to glue and screw tile backerboards in place of the ply. You can use either 6mm or 9/10mm. That is assuming the floor is deflection free i.e. has no bounce to it.

ossm145 · Post by **ossm145** » Tue Apr 01, 2014 8:04 am

Thanks for your reply ,
I had to replace the boards as the old one had rotten and had wood worm, also I had take the the main stud wall down and ran the new boards straight into the landing,
So when you say backer boards is this some kind of tiling sheets ?

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ossm145 · Post by **ossm145** » Tue Apr 01, 2014 10:12 am

Hello ( Think I originally posted this in the welcome area )

I am about to have my bathroom tiled and the tiler said to install 5.5mm plywood ?

No I have just taken up the old floorboards and replaced with t & G white wood 18mm on joist 500mm apart. which i used spax floorboard screws 2 to each joist

Can you please advise if wbp 5.5mm is ok

moderator2 · Post by **moderator2** » Tue Apr 01, 2014 10:16 am

Actually you posted it in the "showcase gallery". I moved it to the tiling forum approx. 4 hours ago.

I'll merge the 2 threads in a mo.

ossm145 · Post by **ossm145** » Tue Apr 01, 2014 10:18 am

Thanks

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Timllfixit · Post by **Timllfixit** » Tue Apr 01, 2014 2:17 pm

When I tiled our bathroom floor a year or two ago, the tile place recommended "Dukkaboard". It seems to be hard foam stuff with a cement layer on each side. It is easily cut with a Stanley knife and is simply screwed down to existing boards via the special washers. I used 1" no 8 screws every foot or so.
The stuff is about 10mm thick, and I laid some 600x600 porcelain tiles on it(8" joists) using a powder mix flexible adhesive and they haven't moved yet. May be worth looking at that, as it MIGHT work out cheaper than 18mm ply.

ossm145 · Post by **ossm145** » Wed Apr 02, 2014 8:45 am

I have decided to go with 9mm ply wood, as I have took all your comments on board and found that there is now bowing or movement on the floor boards and is only a small area 2.8m x 1.9m
Would you recommend to glue the folly wood down as well ?

This will give me a total thinkers off 27mm

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wine~o · Post by **wine~o** » Wed Apr 02, 2014 4:38 pm

ossm145 wrote:I have decided to go with 9mm ply wood, as I have took all your comments on board and found that there is now Is there "now movement" or "No Movement??bowing or movement on the floor boards and is only a small area 2.8m x 1.9m

Would you recommend to glue the folly wood down as well ?
What is "Folly wood" ??

This will give me a total thinkers off 27mm Take it you mean thickness ??

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No-one on here is going to say "Yes 9mm ply will be fine.............. It might be, it might not. You pay your money you take your choice. Regardless the ply should be securely fixed, screwed not glued.

darrenba · Post by **darrenba** » Wed Apr 02, 2014 5:07 pm

I'd be worried that the tiler asked for 5.5mm ply - makes you wonder what sort of tiler he is?

ossm145 · Post by **ossm145** » Wed Apr 02, 2014 5:30 pm

wine~o wrote:
ossm145 wrote:I have decided to go with 9mm ply wood, as I have took all your comments on board and found that there is now Is there "now movement" or "No Movement??bowing or movement on the floor boards and is only a small area 2.8m x 1.9m

Would you recommend to glue the folly wood down as well ?
What is "Folly wood" ??

This will give me a total thinkers off 27mm Take it you mean thickness ??

Sent from my iPhone using Tapatalk
No-one on here is going to say "Yes 9mm ply will be fine.............. It might be, it might not. You pay your money you take your choice. Regardless the ply should be securely fixed, screwed not glued.

Typed on my phone !

wine~o · Post by **wine~o** » Wed Apr 02, 2014 5:43 pm

ossm145 wrote:
Typed on my phone !

I know...still doesn't explain what "Folly wood" is though ??

steviejoiner74 · Post by **steviejoiner74** » Wed Apr 02, 2014 5:45 pm

wine~o wrote:
ossm145 wrote:
Typed on my phone !
I know...still doesn't explain what "Folly wood" is though ??

That's where they make all them silly films is it not??

ossm145 · Post by **ossm145** » Wed Apr 02, 2014 6:09 pm

I meant to say ply wood

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wine~o · Post by **wine~o** » Wed Apr 02, 2014 6:14 pm

I stand by what I said earlier. No-one is going to say "yes, 9mm will be fine" it might be OK, it might not be.

Edit, see colour republics post.