Floor tiling - 18mm ply

[GaryVenters]

Got to tile a bathroom floor. After removing the vinyl tiles I have noticed that the chipboard floor is damp from an old leaking pipe from ages ago. Is it ok to rip the chipboard floor up and lay 18mm ply onto the floor joists and tile ?

[Alan.P]

Yep, that's the way to do it, use WBP ply and use an SBR primer on the UNDERSIDE and edges, if there's any movement in the floor at the moment then brace the joists, then get a good flexible adhesive suitable for ply, cement based ( bags ) not tubbed gear

[nybor62]

as above

[david campbell]

i would use 25/28mm ply and add extra noggins between the joists

[wetdec]

i would use 25/28mm ply and add extra noggins between the joists

Always use the maximum thickness you can get away with screwed @ 300 centres and nogged as Dave has pointed out...................

.

[mikethetile]

all sound advice above

[Scott]

28mm i didnt even know they did it, i wouldnt wanna carry that up the stairs!

[richard Kent]

Gary sorry to hi-jack your thread but I have a question much along the same lines.
I have a floor tiling job to start, floor is 18mm WPB fixed every 150mm (6" in old money)
I would normaly use Bal rapide flex £46 for 20kg, but I was in Wickes and they do a 20kg bag of rapid flex for £16.
Has anyone tried it? or should I stick with what I know works?
Thanks in advance

[Scott]

"Stick" with what you know!

[timeless john]

Whatever thickness plywood you decide to use I would always overboard with a 6mm hardi backer board/similar.

[paul flight]

reply with 18mm screwed at 20 cm centers .watch out for any pipes and cables when fixing boards down. brace across joists befor fixing ply. when boarded fix flexi matting which will help with any movement use a good flexi adhesive to fix matting and tiles . also use a flexi grout . ( B A L. are top product for doing this )

[wetdec]

Whatever thickness plywood you decide to use I would always overboard with a 6mm hardi backer board/similar.

Can you explain why then John ??

[david campbell]

Gary sorry to hi-jack your thread but I have a question much along the same lines.
I have a floor tiling job to start, floor is 18mm WPB fixed every 150mm (6" in old money)
I would normaly use Bal rapide flex £46 for 20kg, but I was in Wickes and they do a 20kg bag of rapid flex for £16.
Has anyone tried it? or should I stick with what I know works?
Thanks in advance

get yourself a trade acc at tile giant you'll save a few quid straight away with the kerquick mate as a astraight swap for the bal flexi,sound as if you are paying full price

[david campbell]

Can you explain why then John ??

it's a better and more reliable surface to tile onto(i think)

[GaryVenters]

You say use an SBR primer on the UNDERSIDE and edges, do you have to prime the Topside aswell of the ply ?

[GaryVenters]

Yep, that's the way to do it, use WBP ply and use an SBR primer on the UNDERSIDE and edges, if there's any movement in the floor at the moment then brace the joists, then get a good flexible adhesive suitable for ply, cement based ( bags ) not tubbed gear

You say use an SBR primer on the UNDERSIDE and edges, do you have to prime the Topside aswell of the ply ?

[david campbell]

not unless the adhesive recommends this,to my knowledge only unibond instructs this and not many tilers would use there stuff

[GaryVenters]

not unless the adhesive recommends this,to my knowledge only unibond instructs this and not many tilers would use there stuff

Thanks Dave, thinking about it I may also put 6mm hardiebacker on top of the 18mm ply, do you reckon thats best ?

[david campbell]

it's a more stable backing for tiles mate so if you have the space then i would go for it