Re: Cutting concrete for drain
Posted by ED on July 19, 2004 at 13:53:35:
In response to Re: Cutting concrete for drain
Most codes require a minimum of a 2 inch pipe under a concrete slab. You can still use a 1 1/2" drain and trap for the sink and connect it to the two inch stub out.

The tie in point to the floor drain for the new line has to be accomplished using a wye or a tee-wye. You can use fernco connectors to tie the new fitting with the existing drain, or glue the new fitting to the existing. Probably easier to do the FERNCO coupler for a non-pro.

The cutting of the floor is no small matter for a length of 25 feet or so. You could rent an electric jackhammer, but it's hard work! You will want to score the floor first with a circular saw with a concrete cutting blade that way you will get a clean cut with the jackhammer. If you have a "sense" where the drains run under the concrete, then you can draw the path. Some plumbers and professional drain cleaners like a Roto-rooter type firm can also run a snake-like transmitter through your pipes and with equipment that sends a signal to a receiver trace the "actual" path on your floor as to where the pipe runs.

Be carefull not to hit the existing drains with the jackhammer. You will also have a lot of ruble to deal with from the concrete cut.

: I'm not too clear on just your question, but if you mean how do you connect the new drain with the existing, it done would be with fittings called no-hub. The 5-3/4" slope over 23 feet is exactly 1/4" per foot, so that will be OK. I'm not a plumber, so I'm not sure what size drain you should use for that new section. I think, underline "think" 2" would be sufficient for a sink. Pehaps even 1-1/2", but do check that with code before proceeding. 3" of concrete over the top is plenty since it will not be subject to any serious weight, and if you saw the trench, that will result in a narrower width to cover than if you break it out.

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