Sealflipperpie
New Member
First off, long time listener, first time caller. Huge thanks to all the pros who take the time to share their knowledge on here.
I'm deep into some underground work after a groundwater flood led me to gut my basement and chip up the floor to install a perimeter drain and sump pump, that's about done, but I have a few "while-I'm-at-it" tasks left. In 8 years in this 1950s built home, I haven't experienced any city sewage backups, but with my laser level I was able to confirm my basement floor is ~30" below the next upstream manhole meaning I'm theoretically susceptible to sewage backup, (note that I don't have any floor drains, so the lowest fixture will be toilet with a bowl ~16" above the floor). While I had a jackhammer rented, I revealed the sanitary mainline where it leaves the foundation, and it turned out to be 3" cast iron with a slope of 1% according to my angle finder.
The trouble is options for 3" backwater valves seems to be limited to just the typical hardware store normally closed swing check valves, which seem to have some drawbacks and don't meet the Canadian plumbing code which states normally open is required. While I could in theory use adapter couplings (eccentric on the downstream side) to install a full port, normally open style valve, they have a much greater vertical offset between the inlet and outlet, meaning I wouldn't be able to achieve the proper slope.
I'm aware I would ideally have only the basement fixtures protected, but that isn't feasible without having the access ports in the middle of my bathroom floor, so for ease of installation, the main line option that will located it in a storage/workshop with a concrete floor is preferred.
Between being limited to normally closed valves, and the small 3/8" offset meaning my 2' long valve and cleanout spool will end up with effectively no slope, I think it's best to take a step back and reevaluate my options. Are there any other backwater protection products or installation tips I'm missing here that could mitigate these installation issues? Note that I don't have a permit pulled, so I won't be subject to inspection and code compliance, but obviously reliability and functionality is paramount.
Here's a few potential options I've been considering:
- Reveal more pipe to spread the offset over more length, giving me a longer section with reduced slope vs. a shorter section of no slope. I'm not sure options is better.
- Mainline Straight-fit valve has a vertical offset of 1/4" for the 3" valve, 1/8" less than the typical options, doesn't sound like much, but perhaps worthwhile in my situation to eek out any bit of slope I can:
- Mainline Topgate valve appears to be an accessory for their Straight-Fit valve, a somewhat unreliable looking mechanism to have a normally open, top hinged valve with minimal offset. It does not come in 3" so I would have to install a 4" valve body which has a 3/8" offset, eliminating the main benefit of the Straight Fit valve. It also does not appear to be readily available online, but it if it seems promising, I can try making some calls. Its also offered with an optional alarm.
http://backwatervalve.com/Upload/pr...able-bwv/Mainline-Top-Gate-Valve-Brochure.pdf
- Protect just the basement fixtures each with their own valves. This would required underground valves for the tub and toilet, the tub required significant rerouting as the it's branch connects to the main below the tub. I would need to figure out how to provide access in the middle of the bathroom's finished floor, which was intended to be vinyl plank on DMX dimple mat subfloor on concrete. A bath mat could assist with that, though I would need to figure out a flush, watertight floor hatch solution as I wouldn't want water getting under the subfloor. Alternatively I could look into a raising the bathroom floor with self leveling concrete or something to be flush with the adjacent floor. Bathroom and laundry sink drains would be about level with street level, but could be protected with above ground valves.
I'm deep into some underground work after a groundwater flood led me to gut my basement and chip up the floor to install a perimeter drain and sump pump, that's about done, but I have a few "while-I'm-at-it" tasks left. In 8 years in this 1950s built home, I haven't experienced any city sewage backups, but with my laser level I was able to confirm my basement floor is ~30" below the next upstream manhole meaning I'm theoretically susceptible to sewage backup, (note that I don't have any floor drains, so the lowest fixture will be toilet with a bowl ~16" above the floor). While I had a jackhammer rented, I revealed the sanitary mainline where it leaves the foundation, and it turned out to be 3" cast iron with a slope of 1% according to my angle finder.
The trouble is options for 3" backwater valves seems to be limited to just the typical hardware store normally closed swing check valves, which seem to have some drawbacks and don't meet the Canadian plumbing code which states normally open is required. While I could in theory use adapter couplings (eccentric on the downstream side) to install a full port, normally open style valve, they have a much greater vertical offset between the inlet and outlet, meaning I wouldn't be able to achieve the proper slope.
I'm aware I would ideally have only the basement fixtures protected, but that isn't feasible without having the access ports in the middle of my bathroom floor, so for ease of installation, the main line option that will located it in a storage/workshop with a concrete floor is preferred.
Between being limited to normally closed valves, and the small 3/8" offset meaning my 2' long valve and cleanout spool will end up with effectively no slope, I think it's best to take a step back and reevaluate my options. Are there any other backwater protection products or installation tips I'm missing here that could mitigate these installation issues? Note that I don't have a permit pulled, so I won't be subject to inspection and code compliance, but obviously reliability and functionality is paramount.
Here's a few potential options I've been considering:
- Reveal more pipe to spread the offset over more length, giving me a longer section with reduced slope vs. a shorter section of no slope. I'm not sure options is better.
- Mainline Straight-fit valve has a vertical offset of 1/4" for the 3" valve, 1/8" less than the typical options, doesn't sound like much, but perhaps worthwhile in my situation to eek out any bit of slope I can:
- Mainline Topgate valve appears to be an accessory for their Straight-Fit valve, a somewhat unreliable looking mechanism to have a normally open, top hinged valve with minimal offset. It does not come in 3" so I would have to install a 4" valve body which has a 3/8" offset, eliminating the main benefit of the Straight Fit valve. It also does not appear to be readily available online, but it if it seems promising, I can try making some calls. Its also offered with an optional alarm.
http://backwatervalve.com/Upload/pr...able-bwv/Mainline-Top-Gate-Valve-Brochure.pdf
- Protect just the basement fixtures each with their own valves. This would required underground valves for the tub and toilet, the tub required significant rerouting as the it's branch connects to the main below the tub. I would need to figure out how to provide access in the middle of the bathroom's finished floor, which was intended to be vinyl plank on DMX dimple mat subfloor on concrete. A bath mat could assist with that, though I would need to figure out a flush, watertight floor hatch solution as I wouldn't want water getting under the subfloor. Alternatively I could look into a raising the bathroom floor with self leveling concrete or something to be flush with the adjacent floor. Bathroom and laundry sink drains would be about level with street level, but could be protected with above ground valves.
