New home not moved into yet. We are in south with huge rains. Walkout basement with french drains that worked until the got clogged as we did not extend them long enough to clear construction dirt buildup. Result is water seeping through basement walls. We built usingcinder blocks, filled with rebar steel and filled with concrete. we put moisture proof sealer on walls interior and had painted 2 coates of ames saterproof sealer on exterior plus a foam board to keep rock from damaging wall sealant before we backfilled with rocks then sand. We sustained 20 inches of rain in 24 hours. Basement loked great until 6 hours later, water built up and could not get out. We dug up and found drains, cleaned and water gushed out. Guess the trouble of backfilling with rock and sand was good idea as it is getting to french drain, just blocked. So I know it will work but problem is much greater. We built 8' x 60' concrete porch on back side of house above basement that is underground theinking that water will never get in there...wrong. We have exposed soil which is sandy-clay, mostly clay. They graded and were ready to put grass down. Well, we left a 2' x 2' hole in two areas inf ront of porch for plumber to put cut-off valves for us where water lines enter home. Rain came first. It filled holes with water then pushed through under concrete porches and left huge voids under. Rain came again and now continued to make void under attached garage that attaches to one corner of basement. Now water is running around corner and lying in large hole against house. How do you fill these voids, we cannot reach them. Will anything last or will it continue to happen? Will that bentonite stuff work? Any ideas would be very much appreciated. No one has basements in the south, guess we know why now. mac

I can tell you that the day after a heavy rain, my sump pump will run every minute and sometimes even less for a couple days. There are weeks and maybe months that it doesn’t pump at all, but the rains we get in the spring or fall especially last for days sometimes, and I get very nervous when that sump pump works day and night. I’ve never had water in the basement so I suppose the pump is doing it’s job, but I know how you feel. Anyway, a dry basement is always better than even a slightly wet basement. I don’t think you wasted your money.

You probably should not be covering it up. It is most likely the reason your basement is now dry. Obviously the basement has had a water problem in the past and this was the soloution to it. It is there for a good reason, you can be sure.

Filling the gap depends why the interior drain system was installed and what they installed. Typically, a homeowner sees water in a basement and calls an "expert basement waterproofing company." These companies are 1 trick ponies that apply their product to any problem no matter what the cause (sorry for the rant). So if the gap has some plastic material sticking though, it is probably something like one of these two systems: The main purpose of these systems is when you have water coming through the wall, that gap catches water running down the wall and directs it into the pipe. So filling that gap would be problematic. Or they could have installed just the pipe like the left picture and just left the gravel be exposed instead of filling back the concrete slab. However, if the problem was a high water table working it's way up from below the slab, or the walls are intact and water is seeping in at the footing joint, then that gap really serves no purpose, and can be filled.