Advice on travertine floor

[aytiling]

Ditra stuck down with flexible adhesive straight onto the floor boards (prime floor first), economical and easy to lay. UFH onto the Ditra (I stick mine with spray carpet glue) Fill the whole lot with 2 part laytex SLC. Tile using Flexible adhesive and flexible grout (I think Ditra guide says you don't need flexi, but I use it all the same.). No need to seal tiles before any of this unless using a dark coloured grout. If you seal before grouting it actually stops the grout keying to the holes in the Travertine.
I have found over the years that Ditra is by far the best product for movement, I have used it on uneven floor boards, ones that aren't nailed down, even traveresed missing boards, and never had any problems.
There is no point putting an expansion joint in unless it is at a point where the joint runs right through the whole floor, like where the joining of 2 peices ply would be needed in the door, but Ditra gets over this so no joints needed at all, just expansion around the edges.

 

[Matt]

Ditra stuck down with flexible adhesive straight onto the floor boards (prime floor first), economical and easy to lay. UFH onto the Ditra (I stick mine with spray carpet glue) Fill the whole lot with 2 part laytex SLC. Tile using Flexible adhesive and flexible grout (I think Ditra guide says you don't need flexi, but I use it all the same.). No need to seal tiles before any of this unless using a dark coloured grout. If you seal before grouting it actually stops the grout keying to the holes in the Travertine.
I have found over the years that Ditra is by far the best product for movement, I have used it on uneven floor boards, ones that aren't nailed down, even traveresed missing boards, and never had any problems.
There is no point putting an expansion joint in unless it is at a point where the joint runs right through the whole floor, like where the joining of 2 peices ply would be needed in the door, but Ditra gets over this so no joints needed at all, just expansion around the edges.

Ditra doesn't stop the need for an expansion joint. It would also need to be laid ontop of the UFH, as the idea is to uncouple the UFH from the tiles.

 

[Alberta Stone]

Cement board is nice but it is not a structural material, merely a backer meaning it provides a smooth surface.

Over here the specs are 3/4 inch ply as primary deck glued to floor joists which have crossbracing.
followed by 3/8 inch exterior grade ply glued and screwed to primary.
Bonding agent applied to top sheath layer then the UFH cables are installed.
This is parged over with a flexible thinset, like versabond by Custom.
Once level and ready the Ditra mat is installed and the stone is installed onto that.
Solid and durable with no movement.

And for a small area like 500 sq ft then you should not need a control joint, but I have no pictures of the site so cannot say with certainty if that is correct in this case, but most likely.

 

[teo]

Wow lots of replies.
O today since i had time i lifted some floorboards to see whats underneath.
Before i said floorboards because i haven't looked properly ( i know...sorry for giving wrong informations!)
After lifting the now knackered vinyl i noticed that in the kitchen area theres 18 mm ply all screwed to the joists, the dining area is different, its floorboards 18 mm thick ( tongue and groove) more or less at the same level.
So i was thinking of overboarding with ply again to make everything level (or cement board..depending on prices)then lay the underfloor heating, 2 part latex leveling compound until everything disappear, then since theres a short wall (both sides) that divide the area, to put a movement joint there (its where theres the difference in substrate).
Still not sure about the membrane,since it will make quite a lot of difference in my budget, but if everyone think its necessary i will definitely get it.
I will plan to do it in 3 weeks time more or less..
Thanks everyone for the knowledge given!

 

[Alberta Stone]

Travartine is so fragile that I wouldn't think of putting it down without ditra.

 

[The D]

i will also add to this thread
The use of sheets and boards that are subject to movement from changes in moisture content, e.g. wood-based materials such as plywood, chipboard, wood particle boards, etc. should be avoided if at all possible. If such boards have to be used they should be restricted to small areas and tiles should not bridge joints between boards. It is good practice to seal all exposed edges and the backs, but not the faces, of such boards with a suitable sealer to prevent distortion by atmospheric humidity changes. Care should be taken to ensure such boards are not installed in a condition where their moisture content is higher than the ambient equilibrium moisture content once the tiled installation is in use. Failure to observe this can lead to subsequent warping and distortion of the boards with consequent cracking and delamination of the tiling.

 

[diamondtiling]

Ditra stuck down with flexible adhesive straight onto the floor boards (prime floor first), economical and easy to lay. UFH onto the Ditra (I stick mine with spray carpet glue) Fill the whole lot with 2 part laytex SLC. Tile using Flexible adhesive and flexible grout (I think Ditra guide says you don't need flexi, but I use it all the same.). No need to seal tiles before any of this unless using a dark coloured grout. If you seal before grouting it actually stops the grout keying to the holes in the Travertine.
I have found over the years that Ditra is by far the best product for movement, I have used it on uneven floor boards, ones that aren't nailed down, even traveresed missing boards, and never had any problems.
There is no point putting an expansion joint in unless it is at a point where the joint runs right through the whole floor, like where the joining of 2 peices ply would be needed in the door, but Ditra gets over this so no joints needed at all, just expansion around the edges.

Are you serious? That has to be some of the worst advice I have ever read, Have you ever heard of BS standards? No manufacturer on the planet would agree to honour any guarantee if they inspected an installation such as you specify.

 

[Alberta Stone]

i will also add to this thread
The use of sheets and boards that are subject to movement from changes in moisture content, e.g. wood-based materials such as plywood, chipboard, wood particle boards, etc. should be avoided if at all possible. If such boards have to be used they should be restricted to small areas and tiles should not bridge joints between boards. It is good practice to seal all exposed edges and the backs, but not the faces, of such boards with a suitable sealer to prevent distortion by atmospheric humidity changes. Care should be taken to ensure such boards are not installed in a condition where their moisture content is higher than the ambient equilibrium moisture content once the tiled installation is in use. Failure to observe this can lead to subsequent warping and distortion of the boards with consequent cracking and delamination of the tiling.

That material is industry standard and only on upgraded jobs will you ever find a sheet of plywood in western Canada, the builders all use chipboard, which is then sheathed with 3/8th inch exterior grade ply and we are expected to tile over that...that is the everyday reality of the jobsite.
You can tell them that they need some cement board laid over that and they whine about the added cost, and the height issues which will require them to add a layer of material throughout the rest of the job.
Every spec I have read has said that cement board is NOT structural and so to achieve the 1-1/8th inch minimum thickness of 2 layers of wood you then need another layer of the cementitious board (another 1/2 inch)
So now there is 1-5/8 inch deck upon which another 1/2 inch of tile and mortar goes bringing the total height to 2-1/8th inch which is quite the step up.
So if one has to match up to the level of 3/4 inch hardwood which they just nail onto the chipboard primary there would be a 1-3/8 inch difference.
This has been a constant issue in the day to day here which ditra helps to absolve as I will lay the ditra over the 1-1/8 inch layers of subfloor and then tile which results in very little height difference.

I haven't laid much cement board in years as a result.

Even large, multi million dollar homes are built by the builders this way as a matter of course. Mostly OSB homes here...they use that...um...stuff... for everything these days, even joists and beams.

 

[teo]

Thanks for the answers.
Everything make sense to me now (to an expert would have made sense ages ago :lol🙂.
So the procedure is: prime last layer of ply with sbr (should i prime even the top side to stop the moisture from the screed to warp the ply?), ufh, 2 part latex leveling compound, wait until completely dry, prime with sbr again, flexi adhesive (2 part or single part?)with a 4mm square notched trowel (should be enough since the level compound will be flat) then bed the ditra mat into it (pressing firmly, checking for coverage), then flexi adhesive (again 2 part or single? i would say 2 part) with a 10 mm half moon trowel, then bed the tiles (after back buttering)onto that as usual (i would love spacing to be 2mm as i dont like big grout lines..).
I was wondering how much height over the level compound all of that would add:4mm(ditra+adhesive), and then 18mm(12mm tiles plus the bed of adhesive that when pressed down will probably be 6mm), total 22/22 mm.
Are my calculations correct?
Sorry for asking so many questions..

 

[Alberta Stone]

to achieve the 1-1/8th inch minimum thickness of 2 layers of wood you then need another layer of the cementitious board (another 1/2 inch)
So now there is 1-5/8 inch deck upon which another 1/2 inch of tile and mortar goes bringing the total height to 2-1/8th inch which is quite the step up.
So if one has to match up to the level of 3/4 inch hardwood which they just nail onto the chipboard primary there would be a 1-3/8 inch difference.
This has been a constant issue in the day to day here which ditra helps to absolve as I will lay the ditra over the 1-1/8 inch layers of subfloor and then tile which results in very little height difference.

My math wasn't functioning this morning (didn't have my coffee 😉 ) as I didn't account for the 3/4 inch primary deck, so the difference would be 5/8 inch which is still quite a bit of a speed bump.
So ditra is a great addition to the trade as most builders and clients just will not add extra money to the budget to make things level.