Hello,
We are working on a home addition and are plumbing the second floor for two bathrooms and a laundry. We are on septic and the stub out to the septic tank in the basement is 4".
The bathrooms consist of, total:
2 - toilets
4 - sinks
1 - shower
1 - tub/shower
1 - washing machine (no laundry sink)
If we are reading the code correctly, this is a total of 17 fixture units, correct? With two water closets and zero six-units traps.
We have got some advice (from a friend of a friend that does commercial plumbing...) and they suggested a 4" main stack. It seems that from the code, we would be plenty large enough sized at 3"? Is there a reason that a 4" would be suggested? I understand the larger the pipe is probably less likely to have a blockage or problems, but it seems like a bit of overkill since 4" pipe allows 256 fixture units... and even 3" pipe is 48 units.
For a little more detail, our two toilets are located near the main stack, so we were going to give them each their own 3" branch. Then a third 3" branch to get out to the other fixtures. Since there are possibly three 3" branches total, does this make the necessity to upsize the stack?
Just wondering if we are missing something.
Please let me know if I need to provide more info.
Thanks
Nick
We are working on a home addition and are plumbing the second floor for two bathrooms and a laundry. We are on septic and the stub out to the septic tank in the basement is 4".
The bathrooms consist of, total:
2 - toilets
4 - sinks
1 - shower
1 - tub/shower
1 - washing machine (no laundry sink)
If we are reading the code correctly, this is a total of 17 fixture units, correct? With two water closets and zero six-units traps.
We have got some advice (from a friend of a friend that does commercial plumbing...) and they suggested a 4" main stack. It seems that from the code, we would be plenty large enough sized at 3"? Is there a reason that a 4" would be suggested? I understand the larger the pipe is probably less likely to have a blockage or problems, but it seems like a bit of overkill since 4" pipe allows 256 fixture units... and even 3" pipe is 48 units.
For a little more detail, our two toilets are located near the main stack, so we were going to give them each their own 3" branch. Then a third 3" branch to get out to the other fixtures. Since there are possibly three 3" branches total, does this make the necessity to upsize the stack?
Just wondering if we are missing something.
Please let me know if I need to provide more info.
Thanks
Nick
