Carlsbad Caverns under my Front Steps.

October 9, 2005 5:41 AM

What's the best (most effective and cost efficient) way to fix undermined concrete steps?

I really didn't make enough of big of a deal of insufficient grading around my house post-construction. Now, after 5-years, I'm beginning to see the bottom of the poured concrete steps from where runoff has eroded the surrounding soil. I know I can just fill and grade, but is there anything else I should do?

posted by rzklkng to home & garden (3 comments total)

Find the source of the erosion and deal with it as best as possible. If it is a downspout then put on an extension to send the water elsewhere away from the house. If there is a swale or low spout that runs close to the house, you will need to some grading or place drain tiles to move it away. Ideally you want to keep any water away from the foundation of a house so grade the yard to slope water from the house.
posted by JJ86 at 6:29 AM on October 9, 2005

What JJ86 said.

But sometimes, just controlling water flow isn't enough. Soil types and weather conditions play important roles in managing erosion, and they interact with landscaping choices near many houses. Loose, permeable soils make nice bushes and flowers, but they store water, which becomes ice during winter freezes, and ice will move subsoil, no matter how well you think you've graded and compacted.

You can remove porous soils at the perimeter of a foundation, and add back soil with a high clay content, compact it, grade it, and have better long term results, but it's a lot of work by hand, and if the project is at all extensive, you might want to get a backhoe operator with a removal truck involved. You need to identify water pipes, sewer, etc. that might be in the area when digging, and observe any local regulation with regard to digging in areas where there might be underground services. And after you get it done, you may need to redo your landscaping.

If you just can't get control of the water at it's source, all you can do is try to get rid of it as it accumulates. I know one guy who had a similar problem, who dug shallow trenches, and then ran some buried PVC landscape drain hoses around his house at the base of the foundation. Then he made a couple of external sumps for them to drain into out of plastic barrels he sunk at the corners of his house, and rigged sump pumps and PVC pipes to force collected water from the barrels into a floor drain in his basement, through a couple of holes he punched into the sides of his house above the sills. Stopped his external erosion, and he did the whole project with a shovel and hand post hole digger, over a few fall weekends.
posted by paulsc at 9:06 AM on October 9, 2005

I agree mostly with paulsc, although the exact conditions of your problems are difficult to understand without more details. It could have less to do with erosion than settlement of poorly backfilled areas around your home. Does your home have a basement? I assume in PA that they do. The problems you have may be related to settlement of poorly compacted fill rather than erosion. This can be fixed by simply adding more soil in the settled areas and placing sod so that it slopes away from the house.

Is the area around your home very flat or are there slopes? Erosion is caused mostly around areas that slope steeply and have poor lawn. Erosion is more of a surface problem due to large quantities of water moving along bare ground. The fix for that is to plant sod on any bare dirt and to landscape so as to slow the speed of the water thus preventing it from having too much power of erosion.

If you have water infiltration in your basement this may be a clue to the problem. I recently did some work around the foundation of my parent's home where they had problems with water in the basement. It was a day's hard work of digging down a bout a foot in the problem area, placing some thick plastic sheeting to slope away from the house into a trench also lined with sheeting until a safe distance away where I allowed it to naturally percolate into the soil. I backfilled with a few inches of gravel and covered with topsoil and sod. That area of the basement is now dry.

Around most homes the basements are backfilled with stone or easily porous materials which is fine as long as it has a place to easily drain at the base of the foundation. But builders sometime take shortcuts and don't worry about drainage too much. In northern climates like PA, especially for homes with basements, you want to keep water away from the foundation.
posted by JJ86 at 2:00 AM on October 10, 2005