Stop dihydrogen monoxide infiltration

August 26, 2006 9:57 AM

Seeking advice on how top water seepage in basement

I have a place built in the 1920s with an unfinished basement. A few times a year water will seep through the concrete foundation, leaving it noticeably damp (but no puddles). There is no visible cracks and the concrete seems otherwise "healthy". So:

Might concrete sealant help solve to problem? I'd like to hear from someone with practical experience with this approach.

Other solutions? I was told that places like mine have no French drain, but putting one in would be a major undertaking.

posted by bluefrog to Home & Garden (7 answers total)

I had this exact problem in my 1907 home, and it was quite severe - almost every rainstorm created puddles down there that would take days to dry up. Finally I made sure all the gutters were cleaned and pitched correctly, unclogged the downspouts, and extended away from the house (4-5' or so) those that were draining too close. My basement has not gotten wet since -- the difference was dramatic.
posted by stupidsexyFlanders at 10:29 AM on August 26, 2006

stupidsexyFlanders has good advice. Also, is the ground surrounding the foundation properly graded? There should be a slight slope down & away from the house.

My mom's house had a similar problem. There was a narrow cemet sidewalk running along one side of the house that over the years had settlled so that it sloped *towards* the foundation. Removing this sidewalk solved the problem.
posted by raedyn at 10:45 AM on August 26, 2006

Properly draining water away from the house is important. If after this you still have problems you might look into a sealant and then a french drain, in order of cost and generally in order of effectiveness.
posted by caddis at 1:16 PM on August 26, 2006

The roof is well drained (flat roof draining in the middle). In the back, I have a concrete "patio" that does tend to retain water. I should probably concentrate on that. I have no front yard to speak of (5 feet between the house and the sidewalk), but then the sidewalk is pretty old and might actually be draining toward the house. I'll check it out.
posted by bluefrog at 3:19 PM on August 26, 2006

Ditto on working on the outside drainage before doing anything else. If necessary dig drainage ditches, fill with drainage pipe and gravel, etc. All this is much more effective than dealing with the concrete foundation walls. Make sure all roof drainage is well away from the house and work on those sidewalks and the patio.
posted by beagle at 6:25 PM on August 26, 2006

yeah, if you can, you really want to avoid having to rely on drains/pumps in the basement. my old house had this and it was a nightmare - the pump failed once and the basement filled up with about 5 feet of standing water. in my case i don't think there was anything that could be done aboveground, since this only happened in heavy rains and the water table would rise significantly higher than the basement floor...

vowing "never again" i installed an RV inverter and marine battery to act as a backup power supply for the sump pump. but it was a big, expensive hassle. would not recommend.
posted by joeblough at 11:40 PM on August 26, 2006

Sounds like the patio may have settled towards the house. Sometimes they can be reset, depending on the size and construction, but many times they will break if you try to lift it. It might not be too much to have a mason refinish it so that it slopes away from the foundation. Is it right up against the foundation, or is there room to put a 4 inch trench where you could slope a perforated pipe with some crushed rock ( inch minus) ?
posted by lobstah at 6:31 AM on August 27, 2006