Some time ago I posted a discussion about making a basement french drain (above the slab drain) with a roof flashing tape I found impressive. Someone did ask for a new post when I had it installed, so here it is:
The tape is called Everbond.
1. I wirebrushed and vacuumed about 3 inch strip along the floor against the foundation.
2. Brushed on a primer that is recommended for masonary installation of the tape. The new primer had lot less smell which was good since this was winter and indoor work.
3. I ordered 2 inches wide tape (50′ which was about the length I needed) which was double sided. I cut this in half. I put the tape down in double thickness hoping this would ride over some of the dips and rises in the floor.
4. I used 1 and 1/4 inch aluminum roofing edger which is a simple 90 degree angle and stuck it to the tape using finger pressure. Later I repressed them together using rounded end of a stick.
5. The double thickness tape did not help with dips and rises. The angle held its line and instead the tape stretched to over this voids. If I ever tried this again I would either bend the wall of the angle so the floor part of the angle would conform to the slab or cut the wall side and patch the cuts.
6. There were voids here and there where the tape had stretched, the biggest void being about 1/4 inch. I ended up urethane-caulking the entire length. I hope this would act as a backing to the stretched tape. The joints were patched with pieces of left-over tape.
7. One end is blocked off with bent end of the roof edger, patched with flashing tape and liberal coating of urethane caulk. The other end is left open for drain and I plan to make a shallow dam around this end so that water can be removed with shop vacuum or utility drain pump that can remove water as deep as 1/8 inch. I don’t plan to make actual pit since all I am planning for is 100 year rain. I expect to stay awake as long as the foundation is leaking.
8. This L shaped channel was covered with same roofing edger, using urethane caulk to bond them together. When I put the foam panels against the wall I was able to spray foam the gap between the panels and the edger without the spray foam getting into the channel. Also, the tape and the channel follows a line 1 and 3/4″ from the foundation and there is about 1/4″ gap between the cover and the foundation. This should be enough gap for water if there should be a leak in the wall.

I did not test this installation. I have no doubt this would work, at least for now, and I did not want to live with standing water, at least until the summer. I don’t know if this would last 20 (the manufacturer’s words for their tape) or 30 years (as I hope). The tape has 1/16″ thick adhesive and I was impressed by how it performed as a roof flashing (low pitch, open sun, metal passive vent painted and patched with tar in the past, and temporary standing water).

As for the basement floor, I planned for vinyl flooring, but the slab is too rough for clean edges. I plan to cover the floor with plastic sheet, foam cover and laminated flooring (cheapest) from Lumber liquidators. When I removed the existing commercial tiles, there was smell of mold. I am not sure what I can do in this situation to minimize the mold when it can grow in the vinyl or in the glue. I don’t want to put down ceramic tiles.

Anyway, thanks for reading and good luck to all with similar plans.