Moisture in channel between slab and block wall

Old 05-31-12, 05:56 AM
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Moisture in channel between slab and block wall

Hello: Thanks for your assistance in advance. I'll attempt to be as thorough as possible.

I've been living in my home for 5 years. In that time we've never had a problem with moisture or water in the walk-out basement (to which I was aware) and so two years ago we studded it out and drywalled to create a home office area.

In September 2011, PA received record amounts of rain and my sump pump failed. In a single afternoon I went from a dry basement to 3 inches of water. Of course, a neighbor who lived in his home for 25 years and never had a water problem had water come up his french drain several feet.

After removing the drywall I did have two expansion joints in the block wall (the mason claimed they were expansion joints but, in reality, they were a spot where you could remove the block and put a window in. It's half above grade and it has a lentil over the top). There was a crack in the mortar there so it was ground and repacked. We then proceeded to work, albeit slowly, to put drywall back up once the basement was dried out (we waited about 3 months). I also re-routed rain spouts on that side of the house. These rain spouts were running underground and out to (what I believe was a storm sewer) and a plumber came out and snaked them realizing they were clogged. For now, I just ran down spouting down grade and 10 feet away from the foundation.

Rainy season has returned to PA. And it's another really rainy year. In fact, this past week we've had violent t-storms at least 4 days, each netting 3 - 5 inches a pop. While we haven't had any standing or running water per se, there is moisture in the basement and it has me concerned. In the ~1 inch channel running around the inside perimeter it is partially filled in my a rough-textured material that looks like concrete. It does not come to the top of the channel. In spots there is noticeable moisture (no standing water, just dampness). In those spots the block wall's bottom course is damp in appearance and touch about 1/2 way up. I don't recall these being like this until recently. These channels run to a sump pump pit and it's bone dry.

The one wall with dampness is adjacent to a concrete porch that is several feet thick. So access to the outside will be very limited without major structural changes.

Adding to the mix, I ran a radon test in the basement somewhat recently and it came back rather high at 24 PCi/L which may be related. I'm having some additional steps taken to mitigate this. The block wall has no apparent cracks on the inside and we ripped up the interior flooring down to the slab and any cracks would be hairline in appearance.

I run a dehumidifier in the basement and empty it once every other day during the summer, about once every two weeks in the winter.

First - I'm trying to figure out if what I am seeing is relatively normal - or is it a cause for concern. Maybe I have this vision of a completely dry basement and, given our current weather pattens, it's unrealistic. I do want to avoid getting mold in those channels as well (none is currently visibly present)

Second - Are there any step I can take as a (relatively novice) home-owner to discover the problem.

Third - Who are the best people to call on these matters. Right after the flooding I had a series of basement foundation folks come in and they were trying to sell me interior products (piping around the interior perimeter) which I understand is not the best way to deal with these issues. I've spent thousands of dollars rebuilding the basement and I hate to spend more but wouldn't mind it if it means preventing another flood. I don't really know who to call or trust, though, and it makes it difficult in finding the right contractor. I had a guy try to sell me a 13K dollar foundation system that another guy said was complete rubbish.

Again, thanks.
Old 05-31-12, 03:37 PM
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Welcome to the forums! You will find this advice time and time again on this forum. Water problems must be initially stopped from the outside. If it means digging around your foundation and installing a waterproofing system with weeping tiles, then it has to be. Interior products work until they fail, which is usually right after the warranty is up.
It may help others to be able to see what you are seeing. Could you post a few pictures (not close ups) of your situation?

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