A friend had a crack in their basement and asked if I could help. After a lot if research I decided to go with an expanding 2-part foam from RadonSeal.com
(Radonseal being the brand) because it seemed to get good reviews. If i didn't feel confident in doing this repair I would have just said no-way, call a specialist, but this seemed to be a straight forward fix.
When the basement was finished a number of years ago the walls were just painted in a concrete sealer and framed in+sheetrocked. It looked like a heavy layer of the concrete paint was painted on where the crack was. This obviously did not solve the problem and the basement had been getting wet in this area for years, every time it rains.
I applied the crack repair kit a month ago(06/27/12). Everything went according to the directions, it rained a few times after and that area of the basement was now staying dry so I went ahead and closed up the wall. Over this weekend we had some heavy rain and now that area of the basement is damp again....
It was in the general area, but not in the same spot as before, it is the most damp a couple feet to the left of where the crack is, but I would not rule out the possibility that the foam did not seal the crack 100%.
I dug up outside along the foundation where the crack is, about a 8" to the left and right of the crack and the soil was absolutely saturated with water. A few inches down and it was almost what I would call mud. I poured about a gallon of water in the hole, and it just sat there. About 30 minutes later it looked like it had hardly drained at all, if at all. This is in CT, so its a mix of rocks and soil but the ground isn't usually saturated like this anywhere. There is no clay, but I found a clay-like substance near the bottom of the foundation where I dug up. I assume this is from when the house was constructed. The foam I injected had pushed out some under the dirt where the outside was not sealed (only above ground was sealed to keep the foam from squirting out), so I know the crack was most likely filled completely filled.
I believe the problem is that the water is just not draining from around the front of the house and is causing excess water pressure on the walls and floor of the basement. If there is a hairline crack anywhere, water is getting through. What are the next steps to take? Landscaping? I've attached a crude drawing of how the house is set up. The dirt comes up about 3 1/2 feet from the bottom of the foundation. From the house to about 30 feet there is an increase of about 3-4 feet of eleveation. The house is pretty much in the path where the rain drains. A french drain system was out of the question before because of price and the basement is finished, but this is the only solution I am framiliar with because I helped do this on my parents house and now their basement stays dry, and humidity is never above about 40% with an A/C or dehumidifier running.
Basement_7-30-12.jpg is a Side view
Basement_7-30-12_2.jpg is a vew from the front of the house. The grade around the house is about 3-4' higher in the front.