If you live in one of the tract neighborhoods of New Encinitas or a townhome complex in the Cardiff hills, there’s a good chance your house sits on a slab-on-grade foundation. Census estimates count 8,160 Encinitas units built in the 1970s and another 6,688 in the 1980s. We infer that most of those are slabs, based on how homes of that era were typically built here. There’s no citywide foundation survey, so we confirm on site.
What a slab tells you, and what it hides
With a slab, the concrete you walk on is also what carries the house, and it’s usually thicker at the edges where it does the work of a footing. The upside is simplicity. The downside is you can’t crawl under it, so problems announce themselves indirectly:
- Cracks in tile or grout that line up across a room.
- Carpet tack strips that pop, or a floor that feels higher in the middle than at the walls.
- Drywall cracks at door corners and doors that stop latching.
- A gap between baseboard and floor along one wall.
- Warm spots in the floor, or a water bill that jumped. That can mean a slab leak.
Most slabs from this era have shrinkage cracks, and most of those are harmless. What we care about is displacement (one side higher than the other), cracks that keep growing, and cracks that line up with other symptoms. See foundation cracks if you’re trying to sort that out on your own first.
Common causes in Encinitas slabs
Edge settlement. The slab’s perimeter sits in the soil most affected by watering, runoff, and drying. When a downspout dumps next to the same corner for 40 years, that corner often drops.
Slab leaks. Supply and drain lines run under many slabs. A long-running leak can soften soil and wash out fines.
Fill. Tracts on graded lots can include fill, and poorly compacted fill settles. The only way to know what’s under your slab is the original soils report (if it can be found) or new testing.
Soil type. Expansive soil gets a low-hazard rating for the whole city in the 2023 hazard annex. That’s a citywide call, not a guarantee for your lot. Soils vary parcel to parcel, and a geotech report is the real answer.
Ways to fix a slab
What we recommend depends on the cause, so the list below is a menu, not a prescription.
- Crack repair for stable cracks, usually routing and sealing or injection. See foundation crack repair.
- Slab lifting with injected material for sections that have dropped but are otherwise sound.
- Piers under the perimeter where the edge has settled and needs deeper support. These are typically engineer-designed, and we coordinate with licensed engineers as needed.
- Section replacement where a slab area is badly broken, often combined with plumbing repair.
- Drainage correction, because edge settlement usually has a water story. See foundation drainage.
A caution if your home is newer: some slabs are post-tensioned, with steel tendons under high tension cast inside. Cutting or drilling into one without knowing where the tendons are is dangerous. We check before we cut, and engineering is involved.
Townhomes and HOAs
About 17 percent of Encinitas housing units are single-family attached, meaning townhomes and some condos. In those communities the slab is often a shared element, and the HOA decides who repairs it. Bring your association in early. We’re happy to walk the unit with a board member or manager and write findings they can use. For uneven floors in a townhome, see uneven floors.
Questions we hear around town
Why is the slab edge crumbling by the garden?
Slab edges next to planters take the most water and, near the coast, the most salt. Crumbling there can be surface wear or rusting steel inside. A close look at the exposed edge usually tells us which.
Does a cracked slab have to be torn out?
Rarely. Most slab problems are repaired in place by sealing cracks, supporting the areas that dropped, or replacing a section. Full replacement is for slabs that are broken up badly enough that repair doesn’t make sense.
Is heave different from settling?
Yes. Settling is part of the slab going down; heave is part of it being pushed up, often by water, roots, or soil that swells. They can look alike from the living room, so we map floor elevations to see which way things moved.
We have radiant heat in the slab. Can you work around it?
Usually, with care. We locate the tubing or wiring before any cutting or drilling and plan the repair around it. Let us know it’s there when you reach out.
Get a Free Quote
Send us the neighborhood, the year the house was built if you know it, and what you’ve noticed. We’ll come measure and give you a Free Quote. The bigger picture is on foundation repair.