Hi all, ive been on the wetroom site getting some great info of grumpygrouter and i have swapped forums now for possiblities on general floor tiling.

I am about to buy some travertine stone tiles for the bathroom floor.

I have read some of the other threads that some say 6mm ply some 12, and even 18 i think.

The floor is floorboards onto joists.

Many Thanks for any help

ian

How big is te floor you wish to tile? Travertine is heavy stuff and you will probably find you need to brace your floor to eliminate "bounce". 18mm ply would be best for this IMO.

Grumpygrouter you are everywhere

The floor is 3m x 3m

Also once you have the floor strengthened i would use a product like ditra to prevent any lateral cracking of the stone from thermal stress associated with timber floors......

Originally Posted by itaylort

Grumpygrouter you are everywhere

The floor is 3m x 3m

You had better believe it

Grumpy grouter,
Thanks again for your help, i have been digesting the previous info and looking at if how when why etc

The floor is made up of 3m joists which are at 16 inch centres.
The joists are 8 x 2 1/2 inch in size.
The floor boards are 6 x 1

Is this a normal make up?

Ian

Seems pretty normal to me Ian.

Thanks,
Again to confirm that the floor is strong enough to support the travetine physically, but the weight of the tiles would create excessive bounce which would mean cracking grout problems?

Ian

if it was me Ian, I would be 1)ensuring the current boards are securely fixed to the joists 2)lay self leveling compound (if required) 3)screw 18mm WBP ply down to the boards a no more than 300mm centres, only screw INTO not THROUGH the floorboards and 4) lay Ditra/durabase decoupling membrane 5) lay the tiles!

Sounds a lot of work I know but Travertine, like most stone is expensive stuff so it is a shame not to do it right and have it crack and need replacing!

The thing that amazes me people spend vasts amount of money on natural stone then try and penny pinch when looking for quotes to get them laid

Grumpygrouter,

SOunds good to me. Ive just looked at the website and it quotes,

Before installation, the durabase ci mats are cut to the required dimensions. The thin-bed mortar or flex mortar is applied to the substrate by means of a 4mm serrated trowel. The mats is pressed, (using the smooth side of the serrated trowel), into the previously applied mortar so that it binds with the entire fleeced surface

What is the mortar its refering to?

Ian

Adhesive, Single part flexible

Can the same stability be gained by using a cement based board over the floorboards?
Just looking at options

Cement based boards do not add strength to a floor Ian. 1 company - No More Ply - claim it does as long as you use their own expensive adhesive but no one has produced data confirming so.Are you a bit worried about the finished height of the floor?

Not really, i imagined about 30 mm rise for the floor. I am really just trying to get it straight so that i can move on and get the floor done
i wouldnt want it to fail and start cracking tiles. The durabase seems the more flexible option and with the addition of being waterproof s i think i will gor for that. A bit steep at £165 tho.

Any Ideas where look up ditra for costings

CTD | home

Originally Posted by itaylort

Not really, i imagined about 30 mm rise for the floor. I am really just trying to get it straight so that i can move on and get the floor done
i wouldnt want it to fail and start cracking tiles. The durabase seems the more flexible option and with the addition of being waterproof s i think i will gor for that. A bit steep at £165 tho.

Not cheap I grant you and Ditra is no cheaper but how much would it cost to have to rip the floor up and start again if it did crack? I know my method is belt and braces but with stone (soft at that!) can you really take the chance? The issue really Ian, as far as I see it is that you have underfloor heating and you really need to islolate your installation from lateral movements in the substrate. A decoulping membrane will give you far and away the best schance of doing that.

Cheers Grumpygrouter,

Its seems a good product and very attractive considering the end result of not using it would be cracked tiles.
Just to confirm tho i do not have any underfloor heating going in.

Ian

Originally Posted by itaylort

Cheers Grumpygrouter,

Its seems a good product and very attractive considering the end result of not using it would be cracked tiles.
Just to confirm tho i do not have any underfloor heating going in.

Ian

My mistake Ian, sorry I was confusing this with a similar thread. My method still applies though.

Grumpyfrouter,

Is this, out of interest going to be the same process for ceramic tiling with the membrane?

Will get away with not using the membrane if you wish Ian, if you lay ceramics.

One thing I didn't mention previously is that you will need to seal the back and sides of the ply before laying. Depending on the adhesive you choose, depends on what you should seal it with.

Crikey grumpygrouter this is indeed an in depth knowledge type job

What would you suggest for the adhesive and in turn the sealant?
Also can you over seal the top of ceramics like stone? To protect grout discoloring from traffic?

Ian

Originally Posted by itaylort

Crikey grumpygrouter this is indeed an in depth knowledge type job

What would you suggest for the adhesive and in turn the sealant?
Also can you over seal the top of ceramics like stone? To protect grout discoloring from traffic?

Ian

If you choose to use BAL adhesive Ian, you will need to seal the ply with BAL Bond SBR. with 18mm ply you can use single part flexible adhesive or the rapid set equivalent. With anything less than 18mm ply BAL recommend Fastflex as the appropriate adhesive. My own personal choice (though I can't get it anymore) is Ardex-flex 7001. If you decide on this, you will need to seal the ply as previously mentioned with polyurethane varnish, you will also need to prime the tiling face with Ardex P51 primer.

There is no need to seal ceramic tiles and the grout sdhouldn't discolour form traffic if you don't use a light colour. Mapei Ultracolour plus is excellent in this respect.

Grumpygrouter,

Seal the underside and edges of the 18 mm ply? Not the tilied side of the board, if this is correct can you tell me why you seal the down side,?

There must be another marvellous snipit of experience coming?


Ian

Originally Posted by itaylort

Grumpygrouter,

Seal the underside and edges of the 18 mm ply? Not the tilied side of the board, if this is correct can you tell me why you seal the down side,?

There must be another marvellous snipit of experience coming?


Ian

Hi Ian,
Sorry to disturb you affair with Grumpy , but it is recommended to seal the rear and edges of the board to prevent moisture twisting or warping from the rear. Some manufacturers will say seal the tiled face, but we at Bal don't with our products.......Gaz

Gaz,
That makes sense,

Thanks for the input,

Ian

Originally Posted by itaylort

Gaz,
That makes sense,

Thanks for the input,

Ian

No problem Ian,
I have seen problems because vent or air bricks under timber floors have blocked or removed or rendered over, causing moisture to attack from beneath and undermine the plywoods integrity. This however does not effect cement based backerboards, I feel will be the replacement for ply when tiling onto timber, 10mm minimum when using single part or rapid flexible....that knocks 8mm off the ply height.

Hi
Just ordered 3 sheets of 8 x 4, 18 mm ply . Going to get some BAL BOND SBR to seal the back and sides as you recommended.
What sort of coverage can i get out of this, and is it a neat apply or thinned.
Topps sell it in 1 litre or 5 litre.

We are going with ceramics now after all.

Ian

Hi again,

Seen ther mapei ultracolour on screwfix and it comes in 5kg bags, does anyone know what sort of area this would cover?
Also is there a good adhesive to use from there so i can order all in one go, single part flexible adhesive was suggested but the description on there doesnt go into that detail

Many thanks

Ian