The laundry room in my house is on a standard wooden floor above the crawl space, not on concrete. So here’s the problem. The only floor drain you can buy is for flush mounting to the floor. And when the water softener and furnace condensate drain lines flow into the drain, there will invariably be water running onto, and ruining, the finished floor. It’ll also seep under the drain and eventually rot out the subfloor underneath the finished floor.
I invented a solution—a recessed drain using standard PVC plumbing fittings—but in an unconventional way.
First I traced around the 4-in. sewer and drain adapter and cut out the opening, just a little larger than the fitting. Then I glued it to the sides of the opening, flush to the floor with construction adhesive. (Wedges made from small shims held it in place while the glue dried.) Then I glued on a 4-in. coupling and then a 2-in. reducer and slipped in the 2-in. PVC pipe to hook it up to the trap down in the crawl space. The 2-in. floor drain just drops into the opening; there’s no need to glue it because the whole contraption is sealed perfectly. Now the drain lines flow into the deep recess, so there’s no need to worry about errant water wrecking the floor. It works perfectly.
— Travis Larson, Senior Editor
For some basics on working with PVC pipe, check out: