new 1/2 bath questions

thomisApril 20, 2012


I'm installing a new bathroom in my house. I have a few questions.

Long story short: This part of the house used to be a carport. It was made a bedroom about 20 years ago by previous owner. We began the demo work a couple weeks ago to add the 1/2 bath and when we pulled up the subfloor (OSB board) there was a concrete slab. The pics tell the rest of the story.

You can see in the last pic I have the cold and hot water supply run (tee'd off the cold and hot to the adjacent washer and came up through the concrete) There is about a 20" crawlspace under the slab. Now for the questions.

Can I go ahead and put the flooring (pergo) down first, and then come back with the flange and toilet or should i fix the flange to the osb board and then cut the pergo flooring around the flange?

I am doing a 3" drain line from the toilet and plan to tie it in to the 3" cast iron drain line from the sink in the bathroom at the other end of the house. I would tie it into the 4" cast iron drain line from the toilet at the other end of house but there is a foundation support in the way and i can't get enough fall in the line that way as well. There is a vent right next to the washer you can see in the photo which I will tie into. The 1.5" drain from the new sink will be tied into the 2" drain line for the washer. Are there any problems with this?

Thanks very much for looking.

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The underside of the closet flange MUST BE in firm contact with the finished floor.

Put down the subfloor and pergo then install the flange on top of the pergo and screw it down tight.

Code prohibits installing a horizontal vent line at any point which is 6" below the flood level rim of the highest fixture served by that vent.

In this case a simple solution would be to install a riser in the wall behind the lav with a Sanitary Tee where you want to stub out the fixture arm to the lav trap. The line above that tee can continue to rise at least until it is 6" higher than the flood level rim of the Lav at which point you could continue upwards and join the vents in the ceiling or you could run the vent horizontal through the wall.

In this configuration the vertical vent above the sani-tee serves as a dry vent to the lav and the vertical drop and horizontal line from the sani-tee down and across to the WC line serves as both the drain for the LAV and the vent for the WC line.

NOTE: you must use a Sani-tee on the vertical behind the lav but at the point where that vertical ties into the horizontal at the bottom you must use a Wye & 1/8bend or a Combo and put a thread adapter and cleanout plug on the end of the Wye.

You must also use a Wye to connect to the WC line- Tee's are prohibited on a horizontal line.

    Bookmark   April 21, 2012 at 8:22AM
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Lazy pup, awesome illustration. Thanks so much for your time.

    Bookmark   April 24, 2012 at 12:30PM
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