First time poster - so apologies in advance if I've missed anything important .
I am doing my current patio which is approx 45 sqm and a walk way down the side of the garden (I've been told I need approx 80 sqm of slabs covering any extra). I was looking at Porcelain or Sandstone slabs.
However my builder is saying if I go for porcelain I need a uncoupling membrane for the full 80 sqm but for sandstone I don't. Do you mind explaining why that is the case that for Porcelain you do need it but for Sandstone you don't?
In addition, is it actually something you need? And do you recommend Ditra Drain? or is there some other brands you recommend. All of this adds up to quite a lot of cost!
Finally would you recommend Porcelain over Sandstone?
I do have a few questions of the back end. Firstly, on the Thin Bed Adhesive method in the article, it says about a damp proof membrane "If needed" why would it be needed?
And is it different for porcelain vs sandstone?
Also I guess if you are using vitrified porcelain and also waterproof grout, why would you need this damp proof membrane? Also similarly why would you need a decoupling mat? And again why would you not need it for sandstone?
Decoupling membranes are 'usually' used indoor in wet rooms for reasons of waterproofing. However they can be used 'throughout' internally to guard against cracking screeds. i.e. Screeds can crack but your tiles won't because you have the membrane which 'absorbs' the movement and stops the tiles cracking.
I must admit I've only used them in wet rooms/garage. I have heard that Schluter do one for external use but you'd be worth checking because usually they're not made for external use (so my tiler said - and he's the don-daddy of tilers).
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