Log in

View Full Version : Can you pass water or drain lines through the foundation, below ground level?


DionD
Sep 28, 2010, 04:40 AM
From Toronto Canada
I am planning on building a cabana by our pool and installing a Saniflo macerating toilet. The drainage pipe for this is 3/4" PVC pipe. Due to the ground grade and distance of the cabana to the house (40') to give the drainage adequate downward slope, by the time I reach the house I am about a foot or two below ground level at the house.

Can you drill from the basement through the concrete foundation below ground level? If so, how do you prevent the hole from leaking after you run the 3/4" drain pipe through?

Thanks

joypulv
Sep 28, 2010, 05:33 AM
My house is built on a concrete slab and has all sorts of waste, drainage, and heating pipes running through and under it, and other pipe like oil fill coming in through the concrete wall on the back slope. You drill through it and concrete patch around it both inside and outside (comes in small tubs so no need to buy a 40 lb bag), and squirt expanding urethane or epoxy foam around the edges from the inside if you ever see a leak or a crack. Since you will have excavated a bit outside you could also put concrete sealer on the exposed part (needs to be clean and the new patch dried a while). If you can't find a small size of that, try a small tub of roofing tar.

massplumber2008
Sep 28, 2010, 05:59 AM
Hi all..

With the saniflo system, the macerator pump chews everything up real well and then pumps the effluent to a certain height (3-15 feet maximum), but the pipe MUST pitch from the high point at the pump to the waste line it connects into at 1/4" per foot of pipe because the pump is not designed to pump great distances and needs the aid of gravity to empty properly.

Joypulv gave his/her experience but according to plumbing code, any pipe that penetrates a foundation wall MUST be sleeved by a larger pipe. The annular space (space between the PVC drain pipe and the inner wall of the sleeving pipe) can be plugged with a hydraulic cement to prevent leaking/water issues... see image below.

In my opinion, you will also want to set the drain pipe up at the cabana so you can disconnect the saniflow pump (put in warm place for off season) and blow the drain line down for the winter season. Be sure to cap the drain line off during the off season so sewer gasses don't escape, OK?

Any questions just let us know...

Mark