Plumbing too close to edge of slab
A plumber set a vent pipe within a 1/4″ of the edge of the slab on one of our jobs. When we told him to move it, he cried. I was surprised to find that this was not covered in our specification and I could not find it in code documentation. In fact, I could not find it anywhere. We have all seen concrete on the edge of a slab bust out around a vent stack or a piece of rebar that was too close to the edge of the slab.
So what is too close?
If there is a brick ledge this is a moot point as the extra concrete for the brick provides coverage for the pipe. but it you have a 2X6 wall with siding and a 4″ vent stack and the pipe is perfectly centered you only have 3/4″. Is that enough? But wait, you have to have your rebar cage in there too. If you are only using #4’s your are at 1/4″ coverage.
Note: we are building monolithic slab on grade with no basement.
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