Advice on travertine floor

[The D]

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.

not my words m8 it is a quote from BS5385

 

[teo]

Got all the material here so i am ready to do it in a couple of weeks.
Is my step by step procedure the right one?
Also since i like small grout lines is 4 mm really required?(i was hoping to do it in 2 mm with mapei ultracolor plus grout).
Regarding the priming with sbr..is it better (just in case) to prime every time we have to bond a new material onto the existing one or is it overkill(like plywood before leveling compound and leveling compound before tile adhesive?)

 

[Alberta Stone]

not my words m8 it is a quote from BS5385

They (BSI) want to bill me 182 pounds for that info, 91 quid if I am a member, which is irrelevant over here.
We have a different set of building codes in North America.

So do they indicate what one should seal the boards with? Paint, Silicon waterproofing sealant? or just no indication?

 

[teo]

Hello all.
Got all my materials and this week end i will start.
If i may ask for more advices before i start, i noticed while on a job that the people that were laying the screed had put some of that foam tape all around the rooms edges and where theres an expansion joint.
Do i have to do it even with latex compound? (it will be around 5 or 6 mm thick)
On the latex leveler its not explained if i have to prime it with sbr before laying the adhesive, i guess it will help with adhesion and drying time?
Also is 2 mm grout line ok? I like small lines with big tiles..
Thanks everyone.

 

[aytiling]

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.

Ditra does indeed stop the need for an expansion joint, and no you lay the UFH on top of the Ditra as you would lose the efectivness of the mats if you laid it under, where do you get the idea that you are trying to uncouple the UFH to the tile?

 

[Gazzer]

Ditra does indeed stop the need for an expansion joint, and no you lay the UFH on top of the Ditra as you would lose the efectivness of the mats if you laid it under, where do you get the idea that you are trying to uncouple the UFH to the tile?

Note:
For radiant heated floors, we especially recommend our system Schlüter-BEKOTEC-THERM, the ceramic thermal comfort floor.
Schlüter-DITRA is also recommended for uncoupling of radiant heated floors consisting of thin electric heating mats. Schlüter-DITRA may be installed either above or below the heating mat. However, the uncoupling function is more effective if Schlüter-DITRA is installed above the heating mat.

Schlüter-DITRA - Schlüter-Systems

 

[aytiling]

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.

No one asked you to act on my advice. I do what I have done for 35 years without a hitch. BTW go to Schluter and DK heating and ask them for the process of laying UFH with Ditra, because it was them that instructed us at Fired Earth to do it that way.

 

[aytiling]

Note:
For radiant heated floors, we especially recommend our system Schlüter-BEKOTEC-THERM, the ceramic thermal comfort floor.
Schlüter-DITRA is also recommended for uncoupling of radiant heated floors consisting of thin electric heating mats. Schlüter-DITRA may be installed either above or below the heating mat. However, the uncoupling function is more effective if Schlüter-DITRA is installed above the heating mat.

Schlüter-DITRA - Schlüter-Systems

Crikey that was quick!! That's funny because they told us that the heat generated by the heating mats underneath the Ditra might uncouple the mat from the Ditra, which would lead to hollows in the floor and also might actually MELT the Ditra!! And just say that there was a split in one of the heating wires, by sending a current though the system you can actually find the tile the split is under, uplift, repair and relay, you try doing that with matting on top of the whole thing

 

[Gazzer]

So what about wet heating systems ?? The mat has to go over the pipework....go figure.

How would it melt the Ditra ? either way its either under or above ?

 

[aytiling]

So what about wet heating systems ?? The mat has to go over the pipework....go figure.

How would it melt the Ditra ? either way its either under or above ?

Sure, agreed, but read my edit to the last post though. The melting quote was theirs not mine.