Kitchen Tiles over ply and screed

Grz.26

Hello all,

I will be putting floor tiles down soon in my kitchen diner but the diner part is a suspended floor with ply as the base and the kitchen is screed. Do i need a different adhevsive for the different floors? Someone mentioned I need ditra matting what ever that is, but i think im looking at £300 for the 25 sq/m that i need.

The tiles are small red quarry tiles.

Any ideas?

Many thanks.

Richard

GlynD

One word of warning. You need to check the suspended part of the floor to ensure it will not flex when putting down heavy quarry tiles. You may need to double up with another layer of ply, screwed down at short intervals right across the span.

Grz.26

Can i lay thiner ply ontop as i am worried about the height?

GlynD

Grz.26 wrote: »

Can i lay thinker ply ontop as i am worried about the height?

Don't be deterred by what I say but have it checked out. The last thing you want are your tiles moving. Do you have a strengthened floor already? Do you have enough height to put another sheet of ply there and keep the floor level with the screed section?

Steve_the_fitter

have a look at something called 'no more ply'. If your suspended floor has flex in it is isnt really good enough for tiling without something on top

Steve_the_fitter

i think ditra matting is something similar but not 100% sure

cddc

Ditra matting has been around for years and works well. No more ply is a relatively new product but exellent by all accounts and will mean raising the floor level less than Ditra matting. Whatever you do, use either on both the concrete and the timber substrate as the join between the two will be the point of greatest movement. The number of jobs I have seen that have had a line of cracked tiles down the join between concrete and timber floors is huge. This is because no account has been made of the movement at the join.

ormus

my extended kitchen is half suspended floor and half concrete slab.
so i used sheets of 8x4 hardboard and then flexible adhesive for the tiles.
its been fine for 5 yrs now.

HB is dirt cheap.

tpt

Despite the previous posters points about hardboard i really would avoid it. the point another poster made about the join is right.

I'd advise using 6mm no more ply over the whole lot and then using a flexible single part adhesive from a good trade manufacturer such as granfix or bal. expect to pay around £24 a bag.

Ditra matting has been around for donkeys and works but is expensive and has to be used exactly right or you will get failures. it also raises the height quite a bit.

full instructions can be found here tiling a wooden floor using no more ply

Barneysmom

ormus wrote: »

my extended kitchen is half suspended floor and half concrete slab.
so i used sheets of 8x4 hardboard and then flexible adhesive for the tiles.
its been fine for 5 yrs now.

HB is dirt cheap.

We've got hardboard under our vinyl on the wood part but it's bubbled up a bit, is there anything we can do? Do we need to lift the vinyl and reglue it?

The concrete side is fine.

keystone

I'm really having difficulty with some of the advise above. Neither a cement backer board nor Ditra will provide structural rigidity which is what is needed in this scenario. Its the joists which give the overall strength and ply on the joists provides horizontal rigidity. You can then use a cementboard or membrane to choice. NMP is not new its been around for several years. Its too brittle for me and the "thou shalt use or void the warranty" glue is horrendously expensive.

OP - no don't just overply with a thinner piece. How thick is the existing ply? If overboarding you should use minimum 15mm so if the current is less than 25mm then just replace it with 25mm WPB screwed into joists at 150mm centres. If you've got bounce on your joists then the existing ply needs to come up anyway and you need to add noggins between the joists.

Cheers