Why Slab Foundations Are Common in Montgomery
Most homes built in Montgomery County since the 1970s use slab-on-grade or post-tension slab foundations - they eliminate the crawl space, are cost-effective to build, and work well in Alabama's climate. However, they are directly exposed to the expansive clay soil below, with no air gap to buffer seasonal movement. When clay swells and shrinks, slabs crack, heave, and settle - often in different areas at different rates, creating the differential movement homeowners notice as sloping floors and cracked walls.
Post-Tension Slab Considerations
Post-tension slabs (containing high-strength steel cables tensioned after the concrete cures) require special repair procedures. Drilling into a post-tension slab without locating the cables first can sever them, causing catastrophic and extremely expensive failure. We use cable locating equipment before any drilling or cutting and coordinate with engineers when post-tension work is involved. Do not let any contractor work on your post-tension slab without cable detection.
Slab Repair Methods We Use
Slab repair methods we use:
- Polyurethane foam injection - lifts and stabilizes sections of slab that have settled over voids by filling the void through small drilled holes
- Push piers - installed through the slab to stabilize severely settled sections on larger structures
- Crack injection with epoxy or polyurethane - seals structural and non-structural cracks
- Partial slab removal and replacement - the most cost-effective option for heavily damaged sections in some cases
Slab Repair in Montgomery: Two Checks Before Anyone Drills
Two things must be settled before a slab repair is scheduled, and skipping either is expensive. First, whether the slab is post-tensioned: cables run through many slabs built from the late seventies onward, and cutting or drilling without locating them first is dangerous and can damage the slab structurally. Ask directly how they determine this and how cables are located. Second, whether a plumbing leak is driving the movement: a leaking supply or sewer line under a slab keeps saturating clay after the piers are in, so ask whether a static or hydrostatic plumbing test was run before the repair was designed. Then ask for the elevation readings that establish movement, since cracks alone do not, and confirm who lifts and replaces flooring and who is responsible for tile that cracks during the work.
- Ask how they determine whether the slab is post-tensioned
- Require a plumbing leak test before the repair is designed
- Ask for elevation readings that show actual movement
- Confirm who removes and restores interior flooring
- Red flag: drilling scheduled with no post-tension check
Frequently Asked Questions
Do you offer free estimates in Montgomery, AL?
Yes. Montgomery Foundation Repair Co provides free on-site inspections and written estimates throughout Montgomery County - no obligation. Call (334) 835-5928 to schedule.
What causes slab foundations to crack in Montgomery?
Montgomery's expansive red clay swells and shrinks with seasonal moisture changes, creating differential movement under concrete slabs. This causes slabs to crack, settle unevenly, and develop voids underneath. Poor initial compaction and drought conditions accelerate slab movement in Central Alabama.
Can a cracked slab foundation be repaired without replacing it?
Yes - most cracked slabs can be stabilized and repaired without full replacement. Polyurethane foam injection fills voids and lifts settled sections. Steel piers stop ongoing settlement. Montgomery Foundation Repair Co determines the right repair after evaluating crack patterns and settlement measurements.
How do I know if my slab is settling?
Signs of slab settlement include diagonal cracks at door corners, gaps between the floor and baseboards, doors that drag on the floor, uneven tile or wood flooring, and visible cracks in the slab itself. Catching settlement early reduces repair costs significantly.