What is the best way to install a 48" manhole over and existing live sewer Main? Everyone seems to have a different way of doing things. Im just curious on everyones different ideas. Thanks
Welcome to the Forums NorthWest!:drinkup I don't install sanitary, just storm but the way it's done around here is get a 48" base without the bottom or a cutout cut or formed through the bottom. Excavate around the existing, set the base, pour the invert and then cut the existing pipe. We call them doghouse manholes around here. Some muni's have allowed a 48" riser section with the cutout set on a poured in place bottom around the existing. Then pour invert and cut existing pipe.
Thanks For the response! That is the way we have done it before but Lately i have been hearing other ways to do it also. Thanks again
I'd like to know how others do it differently as well, as I've only seen it done this way.
We do it about the same, but dig around and under the pipe and slide a flat bottom (or cookie) under the pipe then set the doghouse manhole on top, cut the top of the pipe off and pour the invert.
depends on scenario...if it's an existing rcp or vcp line and we can let concrete set overnight,...we'll hand dig underneath the pipe 8" deep, 6' diameter, place 3-8" block side ways 120 degrees apart so center of block is at 4' diameter, order bottom section of manhole with no bottom. set bottom section pour your concrete around your pipe...by leaving pipe in place, your invert is already there. next morning, saw out top of pipe and set the rest of the sections. if it's a pvc line with little flow that's easily by pass pumped...we'll order our manholes with bottom, pre poured inverts and boots. saw out about 8' of pipe (4' each way from center of manhole, set manhole, run new pipe with pvc repair couplings (gasketed, no center stop)...into the boots, tighten...backfill. slicker'n snot on a doorknob