Insulate and Cast the floor

[Fredrik Persson]

Hello!

We are in the process of renovating the bathroom and with that, we need to insulate and pour a new slab.
The hole is 36cm deep down to the cast slab, can you fill it with 30cm of foam plastic and pour a 6cm slab?
Should the old floor joists be removed before casting?

 

[larsbj]

Yes, the studs should be removed, (if they don't have any load-bearing function). I think you should pour 8-10 cm since you have so much space.

 

[Fredrik Persson]

sending an overview image of the floor. The bathroom is an extension with a flatter roof, so no direct weight from above.