Uncoupling membranes

[lux stone]

When fitting natural stone tiles when and where should these be used? How do you decide?

[Dave]

It really depends on the size of the job............small 4 or 5 mtr kitchen floors then probably no..but bigger floors then Ditra will relieve some of the stress from being transferred to the stone thus causing cracks.....some stones are quiet soft so Ditra can help with stress issues..........caused by the substrate moving (expanding ) at a different rate to the tiled surface...

[grumpygrouter]

....especially when a heated substrate?

Grumpy

[wetdec]

I would say it depends on what floor you are laying on. If its a relatively new or heated concrete floor then Ditra mat Durabase CI floor membrane would be an advantage so the lateral tensions dont transfer to the surface preventing cracking. On a prepared wooden floor they would resolve cracking resulting from deflection

[Dave]

kerdi is a crack bridging membrane not an uncoupling membrane....as for durabase products never used them........

[lux stone]

Used Ditra on a recent Travertine 450mm x 450mm job with heated pipework in screed. There was a hairline fracture where the pipe work was. Worked a treat. Customer was pleased I recommended this as two other tilers who quoted said not to worry it'll be alright!

[wetdec]

Originally Posted by Dave

kerdi is a crack bridging membrane not an uncoupling membrane....as for durabase products never used them........

My aploogies Dave head was pointing north. I have corrected my post accordingly 00ps

[Pawelzik]

Originally Posted by lux stone

When fitting natural stone tiles when and where should these be used? How do you decide?

E.g.:
- on a ship, the uncoupling/decoupling matting prevents the stone from the ship´s machine vibrations and from the possible metal shrinking process if the ship runs from a north & cold climate to a south & warm climate.
- inside a lift on the lift´s metal floor
- on wooden grounds
- on screed which is still hard but has some small fraction lines
and others. I think it is a matter of the site conditions, Martin