Window frame directly against concrete slab

[Helge007]

Hello
I am wondering if one can or should place a window directly on a concrete slab, i.e., without a sill. The window is to be installed in an Attefall house for year-round living. Grateful for quick answers.

 

[huggan]

No, you need to have "sylltätning" underneath.

 

[NoOne2k]

Without sill underneath, there are no problems, but as @huggan writes, you should have some form of sill sealing underneath. Preferably real sill sealing made of EPDM rubber. Otherwise, it works well to lay a strip of underlay felt underneath.

 

[Helge007]

Thank you for the quick responses. Yes, if that's the case, I was thinking of possibly doubling it. I have used T-syll 7mm for the beams. Thank you so much for the answers. This was my first question here. Should one close the thread after a while when you're satisfied?

 

[Helge007]

NoOne2k, is the rubber seal superior? Würth promises that the T-syll lasts for 50 years. Do you mean that it insulates better or that it lasts longer? Please elaborate on your answer if possible.

 

[NoOne2k]

NoOne2k, is the rubber seal superior? Würth promises T-syll will last for 50 years. Do you mean that it insulates better or that it lasts longer? Please elaborate your answer if possible.

T-cell is surely a good product; I’ll let the experts decide which is best.

I have placed https://www.isover.se/products/isover-varior-syllisolering under my walls.

The two rolls on it create a higher pressure on a smaller area, which theoretically makes it seal better against irregularities than T-cell where the load is distributed over the entire surface.