Problem with basement waterproofing (floor, drain, stone, installing)

[rstevens62]

My dad, brother and I did this a few months back to the house my grandparents used to live in. They had always had water problems in the basement, the cinder block walls were in good shape, but water seemed to come in around the base and up thru cracks.


We saw cut around the perimeter about 15", and dug out a trench roughly 18" deep all the way around, we then put in that black drainage hose (the type with little holes along it), and filled the trench with pea gravel, we connected the drain pipe to the floor drain on the basement floor.


We waited to put the concrete down, to make sure it worked, and after some heavy rains, it seemed to work great, all the water was going into the drain pipe and discharging out the basement floor drain.


We then went ahead and put concrete over the trench, but within a couple months, the first heavy rain we had, and water was still coming in along the edges of the basement walls.


We are not really sure what we did wrong, and cannot figure it out, just wondering if anyone else had something similar happen or knew what the problem may be. Thanks!

[Frihed89]

The solution is complicated as the problem is due to subsurface groundwater runoff. Constructing a drainage field to combat this is often a daunting and very expensive undertaking, based on geologic/hydologic surveys followed by a big dig and introduction of many yards of gravel and underground tiles. In some cases, installing a large capacity sump pump can work if you can find a way to direct the outflow of the pump off the property to lower ground.

[STLgaltoo]

You “did it yourself” is what you did wrong. We paid 9K to have our old leaky, oozy basement waterproofed professionally. Best $$ spent. French drain around inside perimeter. I give thanks every time I head to the basement.

[MrRational]

Originally Posted by STLgaltoo

You “did it yourself” is what you did wrong.

There's no reason to assume that.
But however well (or poorly) the drain & sump work etc was accomplished...
the exterior grading and downspout work should be done first.

OP: Was that done?

The engineering is long understood and well documented.
The work itself is just brute labor. It's hard to get either one wrong.

[Rickcin]

Sounds like it could be the volume of water that’s in the stone and perforated pipe not being taken quickly enough by the tight line.

I would not have used pea gravel since it impedes the flow and has less voids and has a greater chance of clogging. 3/4 inch crusted stone would have been my preference, however your system should be doing what it did after restoring the concrete slab.

I’m assuming you enveloped all of the gravel in a suitable filter fabric with a layer of visqueen under the newly placed concrete?