Cast new slab on existing slab

[Adam2303]

Hey, I'm going to build a house this summer and demolish the garage where the house will stand. The garage has an uninsulated slab that seems stable, I plan to lay about 15-20cm of macadam on the existing slab, then L-elements with cellplast, etc. I'm wondering what risks exist with that method??

 

[AmatörsnickareNr1]

Hello, how did it go for you and which method did you choose in the end?

 

[Adam2303]

Hi, how did it go for you and which method did you choose in the end?

Hi, I chose to cut the existing slab only where the votes on the new slab would stand, i.e., the load-bearing outer walls. This was to ensure stability, but the old slab was over-dimensioned, so it wasn't really necessary.

 

[AmatörsnickareNr1]

I understand, but what did you do regarding the isolation?

 

[Adam2303]

I understand, but what did you do regarding the insulation?

I insulated the slab with 3 layers of foam plastic equivalent to 300mm.