Crawl Space Jack Installation: Putting Solid Support Back Under a Sagging Floor

It usually traces back to the soil and the support system under your home. Across the Piedmont, around Charlotte, Huntersville, Matthews, Concord, Greensboro, Winston-Salem, and the Triangle, clay soils swell in wet seasons and shrink in dry ones, and that repeated shrinking and swelling cycle can settle or tilt the original support piers under the crawl space. Once a pier drops, the beam it held loses support and the floor above dips. The same moisture also collects in the crawl space and rots the wood from below. Along the coast near Wilmington, Brunswick County, and Leland, a high water table and saturated, sandy soils soften the ground beneath the supports while damp, salty air rots the beams and joists. On slopes around Asheville, runoff and heavy rainfall can undermine hillside supports over time. The sag feels the same from upstairs, but we identify the specific cause under your home during the inspection.

The first job of a crawl space jack is to support the framing and stop the floor from sagging further, which is the priority for protecting the structure. Because the posts adjust, the crew can often raise them gradually to recover some of the height the floor has lost. How much of a lift is realistic depends on the framing, the finishes upstairs, and how far the floor has dropped, and the lift is done in measured stages so it does not crack the drywall, tile, and trim above. We tell homeowners what is achievable for their specific floor and do not promise a perfectly level result.

Often, yes. A jack supports the framing above it, so that framing has to be sound for the support to hold. If a beam or joist is rotted or cracked, it typically needs repair or sister reinforcement first, because a jack pushing on wood that cannot carry the load is not a lasting fix. In the Carolinas, especially in damp Piedmont crawl spaces and in coastal homes where moisture has sat under the floor, rot and support failure often go together. That is why our inspection looks at both the supports and the condition of the wood, and why we may recommend framing repair alongside the jack installation so the support has something sound to carry.

Jacks support the floor again, but they do not change the conditions that caused the support to fail in the first place. In Piedmont clay that drains slowly or in saturated coastal soils around Wilmington and Leland, ongoing moisture is frequently part of the story, both because it softens the ground under the supports and because it rots the wood above them. To keep the floor from sagging again, the moisture that drove the problem often needs to be managed too, which is why we frequently pair jack installation with drainage, a vapor barrier, or encapsulation. We confirm what your crawl space needs as a whole during the inspection.

The price for your home depends on how many jacks and footings your floor needs, whether rotted beams or joists need repair first, and access under the home. You receive a written estimate after a free inspection.

Example ranges for framing repair work