Houses on slab

[Mark Forest]

I have been wary of houses on a slab becuse I worry about having to drill up the floor in case there is a plumbing issue (and there always seems to be a plumbing issue). What are your experiences with houses on a slab instead of a crawl space or basement?

[Sam Leon]

Originally posted by @Mark Forest:

Originally posted by @Sam Leon:

I have done my share of tearing up concrete slab and tunneling under to repair or redo DWV systems.  You do what you have to do.

So this involves jackhammering  out the cement till you get to the pipe?  

Depends on the type of pipes.

If you are talking about water supply lines, it's often more cost effective to abandon the old copper lines and rework the manifold to go up to the attic with PEX.  I wouldn't cut into a cement slab to fix a supply line leak.

If it's a DWV group that you need to reconfigure due to a bath remodel, yes you will either wet saw cut or punch drill sledgehammer to break open the slab.  From there you dig until you get to the pipes.  Depends on the location this may be real hard soil or in South Florida it's mostly easier to excavate sandy soil.  Rework your drains, then backfill and compact.  On top of that I would do a termicide soak application, then a layer of moisture barrier.  Now depending on the size of the opening, you might need to drill holes on the old concrete and tie in some rebars, then pour new concrete, let cure for 28 days.

If it is a underground drain leak for repairs, there are times you can correct that with trenchless lining or bursting depending on pipe size, location and access.

Lastly you can also tunnel under.  Two years ago I had a pipe break 20' from the edge of the house and I cannot break it from above since the foot print was under kitchen cabinets and tiled floors where I have no spares.  I end up hiring for a tunneling job digging a 4' deep 25' long tunnel.  Cost me $22000.

So yes its quite a bit more involved.