Footing & Crawlspace Excavation in Knoxville, TN

Footing and crawlspace excavation is the dig that sets every foundation: trenches for continuous footings, the shallow open area of a crawlspace, or a full basement hole. In the Knoxville area most homes sit on crawlspaces or partial basements, and many hillside lots have a daylight basement on the low side. We dig to the depth and dimensions on your plans, square and clean, and keep the bottoms undisturbed so the concrete bears on firm soil.

Rock is the big unknown

The soils that cover much of Knox County sit on limestone and dolomite, and the depth to rock changes fast. The USDA describes Talbott soils with bedrock at 20 to 40 inches, while Dewey and Fullerton soils are usually more than five feet deep. Limestone also weathers into pinnacles, so one end of a footing trench can be all clay and the other end solid rock. HomeGuide puts unexpected rock during a foundation or basement dig at $15,000 to $20,000 or more in the worst cases. That is why our estimate prices rock separately, by the hour of hammering or by the yard, instead of hiding it in a lump sum.

Soft spots and clay

The opposite problem also happens. A pocket of soft, wet clay or an old filled sink at footing depth needs to be dug out and replaced, or bridged with a design from your engineer. We stop and call if the bottom of a trench looks wrong, rather than covering it up.

Additions next to older homes

Digging beside an existing house takes care. Old footings may be shallow, and Knoxville houses from the late 1800s and early 1900s sometimes have stone or brick foundations. We dig in short sections near the existing wall, avoid undermining it and coordinate with your builder on how the new footing ties in.

Basement digs

HomeBlue estimates a basement dig for a new home in Knoxville at about $3,600 to $6,300, about two and a half days of machine time in normal soil. A no-basement foundation runs about $2,200 to $3,800. Spoil from a basement is a lot of material, so we plan where it will sit for backfill and how much has to leave the site.

Backfill and drainage

Once the walls are up and waterproofed, we backfill in compacted layers, place drainage stone and pipe where the plans call for them and grade the surface away from the house. Clay backfill pushed against a wall in one big load is a common cause of cracked block in this region, so we take it slowly.