correct sub base for bathroom floor

[johnnyg]

Hi all, new to the forum but hope can get some advice.
I have ripped up the tatty floorboards in my bathroom and replaced with 18mm wbp ply straight on to the joists . I have had to leave a 6inch strip of floorboard down a 2.6m length and a 4inch strip down a 2.3m side, this is because of 2 breeze block partition walls sitting on the boards. I have cut them back to the nearest joists.Have packed the ply where needed so everything is level and well screwed down. The total area to be tiled is 2.6 x 2.3 m.
What i need to ask is whether i should over ply the whole lot with 6mm ply for added security or perhaps glue that orange matting( dont know the correct name, sorry) straight on. Didnt want to build floor level up too high because of threshold problems. The tiles i would like to lay are 600 x 300 porcelain .
Mant thanks in advance,
john

 

[faithhealer]

Hi John, Welcome to the forum.
Wouldn't bother with the 6mm, sounds you knew what you were doing with the 18mm. I think you mean a 'Decoupling Membrane' by orange mat! So in order Prime the plywood, flexi adhesive, membrane, then fix tiles with flexi adhesive. Flexible grout.

 

[grumpygrouter]

Hi Johnny, following on from Faithhealers post, I think 6mm is a waste of time in tiling, I hate the stuff. You have done right to use 18mm ply my only question, because you have such large tiles, is what spacing do you have on your joists? it may be wise to re lift your ply (if possible) and put extra noggins in. Also the Ditra/durabase membrane certainly will not harm and will give more security if you are happy with the extra cost.

Good luck, keep us informed.

 

[johnnyg]

thanks faithhealer, will i be alright with the floorboard borders on 2 sides? thats why i was thinking 6 mm ply to cover over the top. But if you say just membrane it, that'll do 4 me.
cheers, john

 

[johnnyg]

hi grumpygrouter
the joists are 16inch centers, and yes they can be lifted,will fit noggins if you think will help
thanks 4 that
john

 

[DHTiling]

John..it looks like your account hasn't been activated...that is why you can only post in the guest forum..

You should have an email with alink back to the forums...this will activate your account...if not let me know and i will email another activation out to you

 

[grumpygrouter]

hi grumpygrouter
the joists are 16inch centers, and yes they can be lifted,will fit noggins if you think will help
thanks 4 that
john

Hi John Yes, anything to make the floor more rigid is always worthwhile.