New floor in bathroom for tiling

[tom_t]

Hi,

I'm replacing part of the floor in my bathroom in preparation for tiling. Current floor has got big "hill" in the middle probably due to not enough space left for expansion.

Current floor is 22mm thick chipboard and I'm planning on replacing with 12mm chipboard topped with 9mm ply screwed 25-30cm centres, is it gonna be ok?
I'm trying to keep new floor as thin as possible to avoid big step into the bathroom.

Is 5mm gap on the edges enough for expansion?

Is it OK to tile just part of the floor? I want to leave area underneath the bath untiled.

I'm planning to prime ply with BAL Prime APD and then use BAL Rapidset Flexible adhesive Grey/White can I use same combination for walls?

I'm planning on installing shower over bath, do I have to tank wall where showerhead is going to be?

Thanks in advance.

 

[ECT]

Would go for a thicker ply, gap fine,no need to tile under bath, no need for flexi on walls unless stone or porcelain No point in tanking at shower head as very little water gets behind it.

 

[grumpygrouter]

I would use 18mm minimum WBP ply instead of the chipboard.

 

[tom_t]

Thanks guys for your rapid response.

grumpygrouter do you mean that instead of using 12mm chipboard + 9mm ply I could use 18mm or thicker ply on it's own? Isn't gonna deform?

BTW where I can buy thicker ply than 18mm? I couldn't find anything in B&Q or WICKES, any idea where to look?

Could someone advise on good internet shop for tiles?

 

[faithhealer]

Could someone advise on good internet shop for tiles?

forget the net when looking for tiles. Get yourself to a tile showroom (not DIY store) where you can see what you are getting, and if you have any boxes left over you can (usually, check first) take them back.

 

[bigneil]

i always use BAL fastflex when tiling wooden floors, self priming, very flexible, suitable for all types of tile and wood combinations.

 

[CTD Marie]

Hello Tom T.

Welcome to the forum.
At CTD we have 50+ branches nationwide. We maybe able to help you out with tiles.

If you let me know your post code i can tell you your nearest branch. If you like i could send you a brouchure out if you PM me your address.

Cheers.

 

[grumpygrouter]

Thanks guys for your rapid response.

grumpygrouter do you mean that instead of using 12mm chipboard + 9mm ply I could use 18mm or thicker ply on it's own? Isn't gonna deform?

BTW where I can buy thicker ply than 18mm? I couldn't find anything in B&Q or WICKES, any idea where to look?

Could someone advise on good internet shop for tiles?

Yes! and no it shouldn't as long as you have supported it properly, maybe put noggins between the joists for extra support if necessary. Ply is more stable than chipboard.

Also if you can find it, try using Ardex-flex 7001 and Ardex P51 primer. Brilliant stuff and designed specifically for timber floors!

Which ever adhesive you choose to use, always check out the manufacturers priming requirements BEFORE you lay your boards. They are not the same. BAL recommend sealing the backs and edges of ply with BAL Bond SBR and NO primer on the tile surface side. Ardex recommend polyurethane varnish on the back and edges AND P51 on the surface for tiling so just check these addy requirements first.

 

[Turkish]

Tom, as Grumpy says 18mm WBP ply then if you use say BAL products you can use SPF adhesive and still be safe in the knowledge that you are covered by their guarantee. You can leave the bit under the bath, no need to tile that as it will be covered by the bath panel. As for tanking the shower area, if it`s a power shower then yes it would be advisable but if just normal then you could leave it as is.

Turkish

 

[bigneil]

The ardex 7001 is great stuff too, but you must prime.. Granfix do one which is almost identical called Ultimate flex, you have to prime for that too.
I still prefer the 2 part mix that BAL do though.

 

[tom_t]

thanks for all your replies...

I'm going to use 18mm Ply (unless I find something thicker)
BAL BOND SBR + BAL RAPIDSET FLEXI + BAL FLEXI GROUT
I might be putting some noggins although bathroom is rather small (1.90x1.70m) and joists are 400mm centres so it should be ok.

I'm also planning to tile bath panel using 9mm Ply, question is how to mount it to keep access under the bath in case of emergency? Magnets/hinges/screws?

 

[Turkish]

You could just make an access panel rather than the whole bath panel itself and affix that with magnets. Somewhere on here there was a thread about access panels, maybe worth a search mate.

Turkish

 

[smurf21]

tom if your using bal fast flex then you dont prime the plywood face you can prime the edges but not the face read instructions on the bag.