New construction in St. Louis county, Missouri.
Looking to build a house with walkout basement and behind the house a detached garage with half bath (corner lot with house facing street with sewer main and garage access off other street). Sewer is only 8' deep so elevations are an issue. The other houses in the area stick the main floor out of the ground a bit and ours will be similar. I can get 2% slope from house to sewer so that is ok. Issue is half bath in garage. I can get 1% slope for this run if I raise the building floor 6" which would be easy to do. Run is about 100' from half bath to house drain connection. Due to the slope of the lot I will need to run this line to the corner of the house opposite the street corner to keep it buried and across under the basement floor. I have been told running under the slab is to be avoided if possible because future work that requires access to the pipe will be much easier if it is not under a building. That seems reasonable but it also seems like the pipe would be protected by the building and not likely to have issues with tree roots, etc, etc. How big of issue is it to run the drain pipe under the floor? Also, how close can drain and potable water lines be? I have seen requirements of 10' for water and building sewer but I think that was for the section that starts 5' from the building which for some reason is treated differently for some things.
How deep does the drain line between buildings need to be? Footings here need to be at least 30" below ground but sewer will be about 24".
Other choice is to put in a pump for the garage. Would like to avoid that if possible but if that is the best way I will do it. I could avoid running the line under the house and also get more depth. Garage just will have a half bath and another sink on the back side of the wall with the half bath plumbing so perhaps I could get a toilet/pump combo unit. A complication is I have a condensing furnace/AC and water heater so current plans show a floor drain. The HVAC is hung from the ceiling so could drain to a higher trap, not sure what to do about the water heater. And the condensate is corrosive - could put in a neutralizer.
Looking to build a house with walkout basement and behind the house a detached garage with half bath (corner lot with house facing street with sewer main and garage access off other street). Sewer is only 8' deep so elevations are an issue. The other houses in the area stick the main floor out of the ground a bit and ours will be similar. I can get 2% slope from house to sewer so that is ok. Issue is half bath in garage. I can get 1% slope for this run if I raise the building floor 6" which would be easy to do. Run is about 100' from half bath to house drain connection. Due to the slope of the lot I will need to run this line to the corner of the house opposite the street corner to keep it buried and across under the basement floor. I have been told running under the slab is to be avoided if possible because future work that requires access to the pipe will be much easier if it is not under a building. That seems reasonable but it also seems like the pipe would be protected by the building and not likely to have issues with tree roots, etc, etc. How big of issue is it to run the drain pipe under the floor? Also, how close can drain and potable water lines be? I have seen requirements of 10' for water and building sewer but I think that was for the section that starts 5' from the building which for some reason is treated differently for some things.
How deep does the drain line between buildings need to be? Footings here need to be at least 30" below ground but sewer will be about 24".
Other choice is to put in a pump for the garage. Would like to avoid that if possible but if that is the best way I will do it. I could avoid running the line under the house and also get more depth. Garage just will have a half bath and another sink on the back side of the wall with the half bath plumbing so perhaps I could get a toilet/pump combo unit. A complication is I have a condensing furnace/AC and water heater so current plans show a floor drain. The HVAC is hung from the ceiling so could drain to a higher trap, not sure what to do about the water heater. And the condensate is corrosive - could put in a neutralizer.