"Wet window well and slab jacking"
Column #861 08/27/11
On The Level
By
Jim Rooney
Q. Our house has a window well in the front. During the 22 years we have lived in the house, the window well has never had a drainage problem. About two years ago I added a layer of stones to help it drain. Then, about a week ago, during a heavy rain, the well filled with water to a level of 3 or 4 inches and the water penetrated the basement window and leaked into the basement. When I realized what was happening, I used a garden shovel to churn the dirt in the window well to try to reduce the water level. The level went down, although I'm not sure whether it was draining more rapidly or simply the fact that the rain was subsiding. What measures should I take to ensure that the well does not collect water during future rainstorms? I would prefer not to put a plastic cover over the window well since I like to use the window to ventilate the work room when I am working in the basement. Should I vigorously aerate the soil in the window well with a pitchfork, then add several inches of new stones? Is the plastic cover the only solution?
A. If your window well hasn’t been a problem over 22 years of intermittent hurricanes-- such as we are experiencing now-- blizzards and sudden downpours then let me suggest that the problem isn’t the drainage from this window well but rather the drainage to it. Most older window wells do not have any designed drainage other than the normal percolation qualities of the soils at the bottom that for you worked for a generation. Modern houses with very large window wells that satisfy the secondary means of egress code requirement do have drains in them that drain to the sump pit. They can and do clog and need periodic attention.
The stone you added merely looks good and disguises the mud that resides at the bottom. It does no harm. Sure, you can loosen the soils in the bottom and that will help but while you’re at it look straight up. It’s possible that your gutters are full and they were overflowing with a good amount of the overflow ending up in the window well. The gutter’s fall line might not be directly over the open well but close enough to it for water to seep in.
Check all the other factors close to the window well that may contribute such as overgrown landscaping, bushes or trees that may have lifted and changed the grade next to your foundation over the years. These things change gradually and we don’t notice that things have shifted. The level of the soils at the foundation should run down and away from the foundation wall at an ideal rate about an inch or so per foot for about four to six feet away. Sometimes this can be hard to achieve but do your best and remember mulch doesn’t count—it must to be good, compacted soils to do the trick.
Remember, should the basement get really wet, the magic number for getting things under control to help prevent mold and mildew growth is 48 hours. Open windows and box fans running on high 24/7 is key.
Q. About 10 years ago we put in some stamped concrete walkways and patio areas around our house. Over the years several splits have appeared in the concrete. These splits apparently now act as expansion joints that divide the walkways and patios into large sections of concrete. Some of these sections have become uneven. In general this is not a problem but there are a couple of areas where the concrete now tilts in such a way as to cause any water that gets on the concrete to run back toward the house. In one area the water is channeled right next to a foundation wall and in another it is channeled to the outside wall of the steps that lead to my basement. In both of these cases the concrete is right against the walls, so the water is going to an area where I don't want it to go.My take on this is that the company that installed the walkways and patios did not dig a deep enough foundation. Is my only recourse to have someone remove the old material and install new? And how would I find someone who could do this kind of work? The last time I looked at people who do stamped concrete (for another project) they seemed to be small companies who install walkways and patios-- period-- and would not be able to remove the old, if that is what I end up having to do.
A. The shifting of your concrete work that’s 10 years old can have a variety of causes such as frost heave in winter or storm water run-off undermining sections so it’s hard to lay the blame to any single cause. Don’t sell the contractors who install this type of work short—if they can put it in, they can take out.
But before you start throwing money around in large sums for replacement, talk to some concrete specialty contractors who do slab jacking. It’s also called mud jacking and you can find them in the phone book or search the web. Archimedes’ hydraulic principles of old work with grout pumps and these contractors drill small holes into a settled slab and as they pump a liquid grout under the slab, the slab rises. These contractors know what they are doing and jacking a tilted slab is infinitely cheaper than breaking it up and re-pouring it.
Keep the mail coming. If you've got a question, tip, or comment let me know. Write "On The Level," c/o The Capital, P.O. Box 3407, Annapolis, MD 21403 or e-mail me at jimrooney@jimrooneyonthelevel.com or inspektor@aol.com.