This past week was a foray into Under Slab Plumbing. The point of this project is to "pre-plumb" our basement so that we can later (probably at least a couple of years later) include plubming fixtures in a basement finishing project. I had to run pipe for drains and vents for a full bathroom on one side of the basement, a half bath near the middle, a furnace drain on the other side, and a stub for a wetbar. This was far and away the largest plumbing project I have ever tackled myself.
First problem I discovered on Saturday, was that our gravelled basement floor was wet. So wet, that every footstep filled with water. This made it difficult just to get around down there, and very difficult to accomplish any digging. I installed a sump pump in one of the pits, but had no power so it didn't really accomplish anything.
Sunday morning, as soon as I thought it late enough not to wake anyone, I called my neighbors to ask permission to use their external power outlet for my sump pump. The graciously "loaned" me their power. Within a couple hours of plugging the pump in, the basement floor was dry, and I started once again trenching for our pipes. My father came over to assist, and we switched gears from trenching to digging the hole for the ejector pit.
For those unfamiliar with an ejector, this is what makes sewage go Up. Normally, in the part of the house that sits above ground, all your drains, toilets, sinks, etc. gradually slope to a central sewage pipe, which gradually slopes to the main sewage line running by your house (or slopes to your septic system). Everything flows simply because it goes downhill -- pulled by gravity. But if you have plumbing in the basement -- or other "below grade" location, something has to push that sewage back Up.
The pit basin is nearly identical to a sump pit basin -- in fact, some basin models can be used for either purpose. The big difference is that once connected, the ejector must have a sealed lid, and a pipe that pumps to your sewer line, whereas a sump pump pit typically has a loose fitting lid, and pumps water to a storm drain, or maybe just into your backyard.
The ejector pit basin is 30 inches deep. Digging into the hard pan of our basement floor for our trenches had been difficult, but trying to dig 30 inches deep was like chiseling through rock. For the last 10 inches or so, we were literally taking our shovels and chiseling at the bottom of the pit, because we couldn't actually dig into it. That took us most of the day.
Unfortunately, that ate up our Sunday, and there was still much work to do. So, Monday, I took a personal day from work, and continued trenching, and eventually started laying the drain pipes. While this work was not nearly as frustrating as digging the ejector pit, it was certainly slow work for a single worker. Once again, I ran out of time, and had to call it quits with still a little work to do.
The county inspector was scheduled to come on Tuesday, so I got up at 5 o'clock to finish the work. I completed the last couple runs, then put stub pipes on everything (so they would stick out of the slab once it was poured. Ended up being pretty late to work that day -- but the good news is that my work was approved by the county building inspector.
The pipes had to stay exposed for the inspection, but with the slabs scheduled to be poured on Wednesday, I once again got up at 5 to go backfill dirt and gravel over the pipes. You can imagine my frustration when I discovered that my slab subcontractor had been waiting on a confirmation call for me, and never arrived to pour concrete. But I was ready!