DWV concrete slab question (everyone probably knows this)

Old 05-25-06, 12:36 PM
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DWV concrete slab question (everyone probably knows this)


I am trying to add a tub in the 1/2 bath in the basement.

First question: Can I link the drain from the tub into the drain currently in use by the washing machine? It is 2" galvanized steel pipe.

Second: Who do I call to get this work done (busting up concrete and running drain line?). Maybe I could break up concrete, and plumber does the pipe work? Or do people call contractors for this type of thing? I need someone to repour the concrete, I am not confident with that as my wife wants 1.5 foot marble tiles and the floor needs to be very flat.

Third: How do plumber types determine whether your vents are suffecient, do they just eyeball things or are there mathmatical formulas? I don't want to get taken for a ride.

Thanks so much for your advice
Old 05-25-06, 06:46 PM
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First question. Yes, if it handles a washing machine it will handle a tub. It also has to be deep enough under the slab to allow room for the trap on the tub so it will drain. You will have only 2 choices if the washer drain is not deep enough, raise the tub onto a platform OR run a seperate drain to the stack and tie it in.

Second question. It depend on several things. Basically, the more hard, grunt work you do; the cheaper the final outcome. If you have a plumber, talk to him/her about what needs to be done. Your plumber will know people who do concrete work, just get references.

Third question. Venting is covered under the plumbing code adopted by your local jurisdiction. It can be a city, or county, or even a state code, but there will be a plumbing code you fall under. This determines what venting you need at a minimum. There are formulas for venting which are code dependent on how they are figured. Some codes are much more liberal than others.

Bottom line for all this, get at least 3 estimates unless you have a plumber you really do trust. Be sure everything is fully discussed and put in writting. Not only on work to be performed but payment.

Good luck with your project...

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