Tiling

Fixing stone/ceramic floor tiles over aluminium sheeting - what thickness of ally?

Anonymous user 09/03/2024 - 2.41 PM

We are at the planning and budgetting stage for our new/self build house. On the first floor we will have underfloor heating (water). In order to facilitate fixing from above the posijoists I am planning to fix 50mm battens at 600mm centres onto a chipboard subfloor. Insulation will then be placed between the battens and the underfloor heating pipes fixed above the insulation using aluminium clips. This is fine for the engineered oak floorboards, which will just sit on the battens at right angles. But what is the best solution for tiling the wetroom areas. I could use marine ply, but that reduces the thermal efficeincy of the underfloor heating. So I am currently thinking about using aluminium sheeting stapled to the tops of the battens and then tiling directly onto that - using a flexible cement-based adhesive. But what thickness of ally should I use? I've seen on another website (which I cannot now find again!) that the sheeting should have some kind of kitemark indicating it won't flex more than 1/360th - or something like that - of its length under a 300lb weight. Does anyone have any idea therefore what min thickness I should be looking at bearing in mind it's sitting on battens at 600mm centres? Or is the whole idea stupid? It just seemed to me that, with the excellent thermal conductivity of ally this could be the way to go.