Drain penetrations in a slab on grade
Hi, we are pouring a 5″ floating slab on grade with several cast iron drains penetrating through the slab.
the drain lines run in the compacted fill below the 4-6″ compacted gravel, 6mil vapor barrier, 2″ tongue and groove xps and the 5″ 4000psi pour with 1/2 radiant pex throughout.
the assembly we are planning on was to cut a hole in the vapor barrier and attatch to the cast iron pipe with tape, then cut a hole in the insulation around the pipe and fill with spray foam and finally to wrap the segment of the pipe that would be in contact with the concrete with thin foam insulation..
does this sound appropriate?
thanks in advance