jill-of-all-trades
New Member
I have some questions about tying the toilet drain in to the main 3" drain in the crawl space. Because it is at the far end of a nearly 40 foot drain line in a 24" tall crawlspace with 6" joists, the drain is about 10" above the ground to maintain slope (1/4 - 1/2 "/ft). There isn't enough room to connect the toilet drain using a combo with a long sweep 90 below a sanitary tee to connect to the 2" vertical main vent pipe. (I'll try to draw and attach a picture.). For now I am thinking of making the following connections - starting from the far (upstream) end of the 3" drain pipe:
1) cleanout; 2) tub drain using 3 - 2 " wye to use branch vent to connect to main vent (will go from 2" to 1 1/2" branch vent); 3) 3" toilet drain line (about 4.5' from closet bend) using either a long sweep 90 combo or a 3" Wye attached to the main drain (depends on which allows the connection due to limited space between drain pipe and joists); 4) 3-2" combo connected to main drain and 2" main vertical vent to serve as vent for toilet? (Question: can this also be used as a wet vent for infrequently used floor drain beneath clawfoot tub if I use a 2" San-tee?); 5) 3 - 2" combo with 2" san-tee to connect shower drain to main drain and branch vent?
My understanding is there can only be one fixture upstream of the toilet and I believe when the tub drains it will "rinse out" anything the toilet may have left behind.
I have seen illustrations where the toilet drain attaches and is vented slightly downstream. Is that allowed under UPC code the way I have planned it?
Lastly, on the other side of the room, there is 1 1/2" vent and branch vent connected to drain line for the sink so that shouldn't be an issue at all. Unlike the toilet.
1) cleanout; 2) tub drain using 3 - 2 " wye to use branch vent to connect to main vent (will go from 2" to 1 1/2" branch vent); 3) 3" toilet drain line (about 4.5' from closet bend) using either a long sweep 90 combo or a 3" Wye attached to the main drain (depends on which allows the connection due to limited space between drain pipe and joists); 4) 3-2" combo connected to main drain and 2" main vertical vent to serve as vent for toilet? (Question: can this also be used as a wet vent for infrequently used floor drain beneath clawfoot tub if I use a 2" San-tee?); 5) 3 - 2" combo with 2" san-tee to connect shower drain to main drain and branch vent?
My understanding is there can only be one fixture upstream of the toilet and I believe when the tub drains it will "rinse out" anything the toilet may have left behind.
I have seen illustrations where the toilet drain attaches and is vented slightly downstream. Is that allowed under UPC code the way I have planned it?
Lastly, on the other side of the room, there is 1 1/2" vent and branch vent connected to drain line for the sink so that shouldn't be an issue at all. Unlike the toilet.
