Cutting into slab

Banbh

Is it possible for the foundation slab of a house to be cut to accommodate a new toilet pipe or would this destroy the damp-proofing? Clearly it's not a job for a DIYer but would any builder be able to do this work or is cutting into the foundation slab a total no-no?
Thanks.

DOCARCH

It's not an uncommon thing to do.

The builder just needs to be make sure the damp proof membrane/radon barrier is fully sealed around the pipe, reinstate insulation, and, make good the concrete floor slab tying any new concrete to the existing.

Banbh

Much appreciated. I wasn't sure it was technically possible.

antiskeptic

DOCARCH wrote: »

It's not an uncommon thing to do.

The builder just needs to be make sure the damp proof membrane/radon barrier is fully sealed around the pipe, reinstate insulation, and, make good the concrete floor slab tying any new concrete to the existing.

How is this to be achieved? Surely you have to overlap the existing barriers to some extent - which means cutting a large hole in the slab without penetrating the barrier (each penetration of the barrier requiring further excavation to allow it to be overlapped).

Victor

Floor slab or foundation slab (i.e. slab foundation, not strip foundation)?

Is there a way around doing this?

Mellor

antiskeptic wrote: »

How is this to be achieved? Surely you have to overlap the existing barriers to some extent - which means cutting a large hole in the slab without penetrating the barrier (each penetration of the barrier requiring further excavation to allow it to be overlapped).

If the insulation is between DPM and slab it gives you a bit of a buffer to cut the slab cleanly.
If it's hard against the slab, you'll need to carefully cut to within close to the edge and break through manually. Not easy