This is Part 2 of how I finished a basement bathroom. Click here for Part 1.
Bathroom Layout – Toilet, Sink and Shower Stall
The next task is to decide where the bathroom fixtures – sink, toilet and shower stall will go. The builder had already roughed-in the plumbing so I didn’t have a lot of choices, but it’s necessary to measure and mark these items to guide the work.
- I verified the toilet rough-in dimension (distance from the wall to the soil stack) because this is an essential measurement for ordering the right toilet. In my case, it was a standard 15 inch rough-in.
- I discovered that the builder placed the shower drain rough-in too close to the soil stack, meaning the toilet would be too close to the shower. The shower drain would have to be moved.
- The width of the shower stall is limited to 3 feet due to the placement of the soil stack and clearance for the toilet.
I measured and marked the dimensions on the cement floor as shown here. Click on the photo for a full size image.
Floor Blueprint
Shower Drain Rough-In
The shower drain was off center and had to moved by several inches beyond the rim of the existing hole in the cement floor. In this photo, a hammer drill is used to make holes for a knockout to recenter the drain.
Drilling Holes for the Knockout
After drilling several holes to weaken the cement, a brick chisel and sledge hammer are used to make the remaining cuts and shape the sides. Be sure to wear your safety glasses because cement chips fly everywhere.
Cutting the Knockout with a Brick Chisel
Here’s the finished cut in the cement floor for the shower drain:
Finished Cut for Shower Drain
The PVC drain pipe is dry fitted before gluing.
Dry Fitting the Drain Pipe
The PVC pipe and drain base are glued together. The shower drain clamp ring, adjustable barrel and strainer are shown here.
Shower Drain Components
The hole is then filled with fine foundation rock, also known as “concrete screenings”. It packs very well for a solid fill.
Filling the Hole with Foundation Rock
The bathroom walls are painted while there’s no worry about drips on the bare floor. The Wagner Paintmate Plus roller is my favorite for painting walls.
Painting the Bathroom Walls
In Part 3 of this series, I’ll build the shower pan.
Bob Jackson
Copyright © 2013 HandymanHowTo.com Reproduction strictly prohibited.
I don’t understand why there is no trap for the shower drain. What prevents the “ode of sewage” in the bathroom?
The builder installed a trap, it’s in the dirt. I verified a trap was there by seeing standing water in the pipe with a flashlight; running a flexible metal snake down the drain and “feeling” two turns; and lastly I accidentally dropped a screw down the drain and was able to retrieve it from the U bend with a magnet. There’s never been any sewer gas odor nor siphoning sounds from the drain that would indicate a problem with the trap.
Thanks for reading,
Bob
Thanks for ther great posts and pictures. I have a question.
Did you fill foundation rock only or poured concrete on top of the foundation rock?
I filled the hole with foundation rock in layers, tamping it down as along the way to fill all voids. Not too hard though – don’t want to break the PVC drain pipe. The foundation rock packs really well. The mortar bed for the shower pan provided the solid cap on the foundation rock. Notice the foundation rocks stops about 1 or 2 inches below the edge of the concrete floor in the photos to create a supporting “plug”.
Thanks for asking!
I am installing a sewage basin from scratch. There is zero plumbing under the concrete to start with. I am going to bust up the concrete and build my rough in. I have everything figured out, except where to connect the vent. I assume I connect it to an existing vent. Can you help? Thank you
You are correct – the sewage basin air vent pipe must be connected to the outdoors. It’s easy enough to tap into the existing plumbing vent pipe in the attic by installing a Wye or Tee fitting, you’ll need to figure out a way to route the PVC vent pipe from the attic to the basement.
Part 10 of the project series details the sewage basin plumbing vent pipe.
Let me know if I didn’t fully answer your question.
Yes, you have answered my question. Thank you for answering so quickly. I have one more question if you dont mind. The sewage basin have no previously cut holes in the side of it. I am assuming that I have to drill my own holes or did I get the wrong basin? My basin is a Parts 2 O brand. I looks like there are extra grommets for that purpose, that come with the lid.
The sewage basin should have preformed inlets on the side for sewage line entrance. If there are two or more inlets, the inlets might be capped. This provides the installer with flexibility in the plumbing configuration by cutting open or both inlets. My basin has two inlet ports, both inlets were capped with an integral plastic covers. Since my basement bathroom has only one sewage line under the concrete slab, only one inlet was cut open and fitted with a grommet to seal the sewage line.
Your Parts2O brand sewage basin should have a factory made inlet. Take a look at this Parts2O basin and read the Technical Specifications sheet towards the bottom of the page.
If your basin lacks factory-made inlet ports then you should consider purchasing a different sewage basin. This Little Giant package from Amazon.com is a good example: Little Giant 9S-SMPX-LG Pre-assembled Package w/ 20″ x 30″ Polyethylene Basin, 1 Piece Cover w/Bolt-
BTW – it sounds like you’ve got a fair amount of concrete slab to cut into to install the sewage plumbing and basin. Instead of drill, hammer and chisel consider renting an electric concrete wet saw. Gas powered wet saws are fine for outdoors but would suffocate you indoors. A tool rental place should have an electric wet saw – faster, easier and nice straight cuts: http://www.youtube.com/watch?v=gUvVzZv4vJ8