# Laying out plumbing for basement finishing - pictures included



## hyunelan2 (Aug 14, 2007)

Ran into the plumbing inspector. I asked him and he drew me a little diagram, which I reproduced. Turns out my washing machine diagram has a "S" trap on it, which is illegal. This way works:


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## jim9944 (Oct 20, 2010)

The standard size water lines used to feed any of the fixtures you mentioned are 1/2". If you are planning on running one set of hot and cold to the entire set of fixtures it may be best to run 3/4 from the source into the laundry/bath area and then split off of it with a 3/4"x3/4"x1/2" T at each intersection and use a 3/4"x1/2"x1/2" T at the last intersection so that a 1/2" line runs to each fixture but only where each one branches off of the main run. We use pex where I come from and I would highly recommend it. Even if you don't have the crimp tool you can get crimp rings that are easily crimped with standard tools or many hardware stores (ACE etc..) rent the tools by the day/half day and it is such a time savings over gluing or soldering. Also about the toilet the standard rough in setback from the center of the 4" drain to the stud wall is 12". This gives enough room between the sheetrock and the toilet tank so they are close at the back but not quite touching once you are finished. Another useful suggestion may be that I could see a slight bit of negative slope on your vent pipes in the drawing. I am not sure if this was intentional or not but you do need this. It must flow uphill from the fixture to the vent stack so as to allow any water that gets into that vent from rain etc. to flow back down into the drain! Good luck, this looks like it will be a nice space when finished. James.


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## the_man (Aug 14, 2010)

In my code, no more than 1/3 of the total length of the vent line can be horizontal. The way we get by that is to upsize one size, you lose the horizontal limitations when you do. I would run all vents in 2" to save from possible inspector issues down the road. Also put the cleanout on the washer vent above the flood level of the box, its unnecessary where it is at (but you can leave it too, can't have enough cleanouts)


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## TheEplumber (Jul 20, 2010)

A 10.5" roughin is about as close as you can get for a water closet. It appears that is what you have. This will take a special order for your WC, but not uncommon. If you push the wall back 2" so you have 12.5" from the framing to center of closet stub you can use a typical toilet


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## braindead (May 31, 2010)

Toilet rough-ins are taken from the FINISHED wall line.:yes:


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## hyunelan2 (Aug 14, 2007)

Thanks for the replies everyone. A few remarks:

Yes, I will make sure the horizontal vents have the correct slope, that was just MS-Paint throwing it off. I also think I will be using 2" for everything - it just seems easier. It's not that much plumbing that the 2" PVC and fittings will make a much more expensive project.

In my toilet research, I am finding that 12" is standard rough-in dimension. The tape line on the floor represents the finished wall, but I still need to push it back about 2" to get an off-the-shelf toilet to fit. Should I just "notch" the 2x4s for the plate board to get it to slide back, then "notch" the studs to fit around the horizontal vent PVC? - Basically frame around the existing PVC? Should I just cut off the vents and frame, then rebuild the vents with the studs in place?


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## hyunelan2 (Aug 14, 2007)

Nevermind. 30 seconds at Home Depots website and I see that 10" rough-in Toilets are commonly available. There are not as many (66 10" vs. 722 12"), but there are enough to choose from.


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