the room. It’s also pretty important that the holes are positioned to sides, not up and down. Until they’re trapped in stone, the pipes are pretty easy to move. Especially if your skull is thick. Fabric. I wrapped my drainpipe in landscape fabric. It probably wasn’t entirely necessary, but I had visions of it filling with silt at some point in the future and since it will be buried in concrete, I figured an extra step was easier now than later.
CONCRETE AND PIT Membrane. The last step before concrete is a dimpled membrane that crawls up the wall above the new slab line and goes past the concrete into the gravel field. I run mine straight down the wall.
Wrapping the pipe in landscape fabric will reduce blockage inside the pipe. This is a good cross-section of a pipe going in. Because the entire floor was dug out here (for adding a bathroom), you can see the stone, pipe and fabric.