Travertine on caberboards

[Grace'sDad]

This is a first for me, but asked to lay travertine on an upstairs floor.

It is a new-build, "moisture resistant" caberboards 22mm. Floating!

My thoughts are:

1) Screw down all boards and ensure that there is no problem with deflection. Use Ditra and standard Rapid Set Flexi.

2) If the floor deflects, screw boards down, cross-overboard with 18mm wbp ply and use Ditra and standard RSF anyway

3) Run a mile!

- White fastflex would be great but the cost is prohibitive on this site job.

[salmonfisher]

i would use 9 or 12 mm ply Dependant on floor then standard Rapid Set Flexi and flexi grout

[Grace'sDad]

Ply and Travertine makes me nervous - should I be?

I thought ply moves laterally more than tiles and as travertine is weak laterally it could split.

I'd be happy enough fixing porcelain coz that's stronger.

[salmonfisher]

what size room?

[wetdec]

Upstairs floors are not brill for Trav under 12mm in any sort of large area especially in new builds that are still moving and I would go straight to option 2 except I would buy Durabase mat from me not Ditra of course

Money is tight maybe but this one needs doing right or not at all me thinks !!

tiler

..

[wetdec]

Ply and Travertine makes me nervous - should I be?

I thought ply moves laterally more than tiles and as travertine is weak laterally it could split.

I'd be happy enough fixing porcelain coz that's stronger.

Now your thinking


tiler

..

[sWe]

I'd screw the boards down, with close spacing on the screws. After the floor feels solid, I'd apply 12mm SLC with a rebar netting in it. That should be enough to counter deflection and movement.

[jas]

Go for choice one mate . Screw down the boards use ditra matting and flexible adhesive.

[sWe]

Decoupling mats are quite rare over here. REALLY rare actually. I realize the standards are different in the UK, and that methods are somewhat different, but here's (roughly) what the Swedish standards say:

The stiffness of any floor which is to be covered by any type of tiles, should be equal or greater than a floor made from 22mm chipboard, screwed down with a screw spacing of 200mm, on joists with a spacing of 300mm.

When the joists have a larger spacing, the floor needs to be reinforced. This is done either by glueing down a 12mm fibrecementboard with an approved adhesive, or by laying down 2.5mm thick rebar netting, which is then covered by a minimum of 12mm SLC. If the joists have a greater spacing than 600mm, perpendicular joists with a spacing of no more than 300mm needs to be added.

As for decoupling: It's usually only done on really large surfaces, or in portions of a surface which will be subject to larger shifts in temperature than the rest of it. It's normally done through putting down two layers of plastic sheets before the floor is cast, and it's normally done in sections, with movement joints in between. Essentially, floating concrete floors.

[steve hardy]

Looking for advice on laying travertine on wet heated sub floor construction made from 50x50 timber 400mm centres 30mm kingspan, 20mm 8/1 dry mix screed between and topped with 6mm ply any ideas how to stop grout cracking plywood moves between 50mm timbers. tiles do not crack just grout.

cheers steve

[Grace'sDad]

Use BAL Superflex with BAL GT1 grout admix. Makes the grout so flexible it bends in the bucket when dry!

Careful though coz it drys very fast on the tile surface and is a nightmare to get off if left too long.

[Dave]

Hi grace'sdad........that will be BAL wide joint grout with GT1 admix.....sorry for correction but you don't mix aditives into a grout that is already got latex hydrated into it........upsets the balance mate.........

cheers sorry again for correction......

[Grace'sDad]

Not at all - Thanks Dave. 50% chance of being right - oh well!

(It's late, I'm tired and I hate doing my finances!)