Good morning all,

I have a floating plug and also a stand pipe for our 4" (clay pipe, I think) floor drain in our basement. However, with the recent rains, I noticed that neither closes the drain completely, sewer water came up in the basement. While the floor drain size and plug sizes are 4", there remain small gaps around the rubber even when I tighten the screws completely. The gaps are away from the screw locations. It's as if the 4" pipe isn't perfectly circular. I tightened everything and I poured water through the gaps, and the water went down the pipe, meaning it is not completely sealed.

The plug for the stand pipe that I tried to use is this:

"Campbell Basement Flood Stopper"

and my plug looks like this (not the same product, but similar):

"Gen. Wire Spring 4FH Flood-Guard"

(no links allowed to post)

any advice? Should I try to ad another layer of rubber around this (although it is going to be very tough since the gaps are small?)