I’m intending to install Toto carrier WT171M in an old house. Would like feedback on sketch of intended DWV. I've been reading a ton and am learning a lot but there is so many different ways that are wrong and so many different things to keep in mind to get it right, that I'm feeling a bit lost.
It’s a 2x4 wall, so I also bought the THU343 outlet assembly Toto offers to enable installation in the thinner wall. It looks janky: small diameter, thin plastic.
My priorities are as follows:
- plan a system that works well so it’s unlikely we’ll have to use the cleanout.
- maintain structural integrity of framing
- avoid (or minimize extent of) need to build out toilet wall to 2x6
Questions:
1. Is the tee wye fitting with "long 90" the proper way to connect my shorter 1.5ft" horizontal 3" toilet drain, into the longer run of 3" drain pipe that will travel ~8.5ft to the stack? (All this portion will be in the floor so it's all horizontal with proper slope).
2. Can I use a 3" elbow "short 90" where the toilet outlet changes from wall to floor? Or is it significantly better to use a regular 90 (in a case where short 90 might be permissible in this location). Wondering if the short 90 makes clogs more likely.
3. Is the toilet suitably-vented by the vent on the lavatory at the upstream end? Or do I need to drop a separate vent line down the wall beside the toilet, and connect directly into the 3" drain pipe in the floor?
4. If I do need a dedicated toilet vent, does it matter if that vent is upstream or down-stream of the toilet? Would the 3X3X2 fitting I'll use in the floor need to be rotated so it's above the mid-line of the 3" drain pipe? Just concerned this will add height to the entire run if it's not permitted to connect "flat".
5. Basically the route for toilet waste is taking one vertical-to-horizontal 90-degree to get from the wall to the floor, then with the wye, taking a horizontal-to-horizontal 90-degree change in direction before running to the stack. Is this bad? Or is it “ok, but given the scenario, definitely avoid using Toto’s reduced diameter outlet assembly?”
PS. I realize changing direction of the drain by 90-degrees in wood framing seems weird. It happens to go with how the house is framed. The floor joists change direction in this location and a masonry wall supports underneath (bathroom is on second storey).
It’s a 2x4 wall, so I also bought the THU343 outlet assembly Toto offers to enable installation in the thinner wall. It looks janky: small diameter, thin plastic.
My priorities are as follows:
- plan a system that works well so it’s unlikely we’ll have to use the cleanout.
- maintain structural integrity of framing
- avoid (or minimize extent of) need to build out toilet wall to 2x6
Questions:
1. Is the tee wye fitting with "long 90" the proper way to connect my shorter 1.5ft" horizontal 3" toilet drain, into the longer run of 3" drain pipe that will travel ~8.5ft to the stack? (All this portion will be in the floor so it's all horizontal with proper slope).
2. Can I use a 3" elbow "short 90" where the toilet outlet changes from wall to floor? Or is it significantly better to use a regular 90 (in a case where short 90 might be permissible in this location). Wondering if the short 90 makes clogs more likely.
3. Is the toilet suitably-vented by the vent on the lavatory at the upstream end? Or do I need to drop a separate vent line down the wall beside the toilet, and connect directly into the 3" drain pipe in the floor?
4. If I do need a dedicated toilet vent, does it matter if that vent is upstream or down-stream of the toilet? Would the 3X3X2 fitting I'll use in the floor need to be rotated so it's above the mid-line of the 3" drain pipe? Just concerned this will add height to the entire run if it's not permitted to connect "flat".
5. Basically the route for toilet waste is taking one vertical-to-horizontal 90-degree to get from the wall to the floor, then with the wye, taking a horizontal-to-horizontal 90-degree change in direction before running to the stack. Is this bad? Or is it “ok, but given the scenario, definitely avoid using Toto’s reduced diameter outlet assembly?”
PS. I realize changing direction of the drain by 90-degrees in wood framing seems weird. It happens to go with how the house is framed. The floor joists change direction in this location and a masonry wall supports underneath (bathroom is on second storey).
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