This project is continued from Part 17.
This installment discusses closing the sewage basin, testing the plumbing and a review of the various plumbing connections. You can read about the sewage pump installation in Part 9 of this project.
Sewage Basin Cover Seal
The sewage basin consists of a two-part metal lid that is attached by six (6) bolts and rubber grommets to seal the various wiring and plumbing penetrations.
A strip of 1-1/4 inch wide by 7/16 inch thick foam rubber single-sided self-stick tape was applied to the rim of the sewage basin to provide and air-tight seal against the metal lid. I chose the extra thick 7/16 inch tape for the extra gap-filling ability. I’ve heard of people using caulk to seal the lid, but that would make it difficult to remove the lid in the future for maintenance.
The cross-seam where the two lids overlap was like-wise sealed using a length of 3/4 inch wide by 3/16 inch thick single-sided self-stick foam rubber tape.
The two-halves of the metal lid were bolted onto the sewage basin, checking that the 7/16 inch thick foam rubber was squeezed to about 1/2 of its original thickness. The idea is the foam rubber tape if left to expand and seal any gaps between the basin and cover; and not to tighten the lid down so much the foam tape is crushed or the lid becomes warped.
Testing the Sewage Basin for an Air Tight Seal
Before declaring the bathroom “open for business”, I needed to verify the sewage basin cover and grommets were 100% air tight. I did this by pouring a bottle of cheap perfume down the sink and running the water until the sewage pump was activated. I then sniffed around the basin for any hint of perfume. I detected no hint of perfume. I waited an hour, ran the water again and rechecked, finding no scent of perfume.
As of this writing, the basement bath has been open for business for two months and there’s been absolutely no odor whatsoever.
Water and Sewer Plumbing Connections
The following is an overview of the completed water and sewer connections. The building inspector said he liked my work when he signed off on my building permit.
Floor-level:
Mid-Level:
Upper-Level: Notice the 2×4 bracing for the 2 inch PVC riser plumbing.
Overhead:
The high water alarm is mounted to the 2×4 wall studs and is on a separate electrical circuit from the sewage pump.
The final installment of this series is here.
Take care,
Bob Jackson
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