Hello!
I am planning to pour a new slab (with underfloor heating) on the existing one from 1974 with 10 cm of foam insulation underneath. Only the exterior walls will stand on the old slab, but with thick sill strips underneath and along the side facing the new pour.
The old slab seems dry.
Two thoughts have come up.
Should I lay age-resistant plastic film on the old slab before the foam insulation is laid out, with an upturn against the exterior walls? Partly as a protection against possible moisture migration through the foam into the new concrete slab and as a protection of walls during the pouring.
Is this a secure solution to prevent any potential rising moisture from migrating through the strips and the film into the exterior walls?
I am planning to pour a new slab (with underfloor heating) on the existing one from 1974 with 10 cm of foam insulation underneath. Only the exterior walls will stand on the old slab, but with thick sill strips underneath and along the side facing the new pour.
The old slab seems dry.
Two thoughts have come up.
Should I lay age-resistant plastic film on the old slab before the foam insulation is laid out, with an upturn against the exterior walls? Partly as a protection against possible moisture migration through the foam into the new concrete slab and as a protection of walls during the pouring.
Is this a secure solution to prevent any potential rising moisture from migrating through the strips and the film into the exterior walls?
