I'm tying into existing DWV to create a new basement bathroom group. Just a few feet away, I have a high-efficiency furnace and a condensing tankless WH. Both produce a decent amount of condensate an the later also has a T&P valve. Right now, all air-gap "drain" functions are into an open (non-sewage) sump w/quality submersible pump that goes up and to daylight if rainwater comes up too high under the basement slab or if I had a gallon or more of condensate/overflow from the appliances. I'm replacing the tile sump pit with a sealed unit for various reasons, radon and air leakage among them. I do still need to deal with the appliances needing to drain. Here are my options:
- have the contractor add a floor drain behind the side wall of the bathroom next to the current sump location. Venting is a concern here since the only way it could get makeup air as they've proposed it is from a vertical 4" waste stack serving two bath groups and a kitchen above.
- have the contractor make a purpose-built standpipe with a 3-4" opening 18" above the floor. Similar concerns to floor drain, but slightly less likely to ever back up and possibly "neater".
- construct a trapped floor drain/pipe that drains into the sump basin concealed below the finished concrete. The trap would keep the basin water/airtight, but I would have a risk of depending on that sump pump to keep the system from overflowing if I ever had a REAL T&P emergency.
The options seem like they each have risk/rewards, but I'm curious what folks have done in similar situations.
Dan
- have the contractor add a floor drain behind the side wall of the bathroom next to the current sump location. Venting is a concern here since the only way it could get makeup air as they've proposed it is from a vertical 4" waste stack serving two bath groups and a kitchen above.
- have the contractor make a purpose-built standpipe with a 3-4" opening 18" above the floor. Similar concerns to floor drain, but slightly less likely to ever back up and possibly "neater".
- construct a trapped floor drain/pipe that drains into the sump basin concealed below the finished concrete. The trap would keep the basin water/airtight, but I would have a risk of depending on that sump pump to keep the system from overflowing if I ever had a REAL T&P emergency.
The options seem like they each have risk/rewards, but I'm curious what folks have done in similar situations.
Dan