Nothing’s more beautiful than a new front porch. And nothing’s worse than a brand new porch that sags because of poor soil compaction. Have you ever filled a hole with dirt and then noticed later that the dirt in the hole is lower than the surrounding ground? That’s soil compaction. If poor soil compaction happens on a bigger scale—say, under your porch or a new stone wall—it can lead to big, expensive structural problems. Soil compaction reduces the amount of air pockets in the soil by forcing particles closer together. Well-compacted soil won’t settle as much, can carry heavier loads, and can prevent water movement.
A lot of projects require you to compact the soil. Compact the soil under footings, slabs, basement floors, driveways, concrete steps, and sidewalks. Also compact the soil around foundations and underground sewer and water pipes. Compaction tools vary from hand-held compactors for small jobs to steamroller-like vibratory rollers that can cover large areas. Tools may be available for rent at your local hardware store; or you can hire a qualified contractor for the job.
When it comes to soil compaction, an ounce of prevention is worth a pound of cure. Do it right at the start, and enjoy that beautiful porch and that handsome wall for years to come.
Source: “Soil compaction in residential construction,” by Fred Owens and W.R. Malisch, Publication #C890855, The Aberdeen Group.
Steps built on top of non-compacted soil. A space is visible under the steps.
After we took off the top row of bricks, notice the dirt and voids underneath the steps. Time and water eroded the dirt underneath leaving spaces and causing the steps to collapse.
This shows the completed, new steps.