What That Crack or Sticking Door Usually Means
People rarely go looking for foundation help first. They notice a door that won't latch or a crack that wasn't there last spring. Each of the common foundation warning signs below gets a short, direct answer and a pointer to the repair it most often leads to.
One sign on its own is often seasonal and minor. Several signs in the same part of the house, or one that keeps growing, usually means the foundation under that area has moved. Note where each sign is, date it and photograph it: a pattern on one side of the house tells a specialist more than any single crack.
Why is there a stair-step crack in my brick?
Brick walls sit on the slab's edge, so when that edge rises or drops, the mortar joints crack in a stepped line. A thin crack that never changes is often old movement. One that widens, or starts at a window corner and runs toward the ground, suggests the slab is still moving. See foundation crack repair.
Why is there a crack above my door or window?
Door and window openings are the weakest points in a wall, so movement shows there first. A diagonal drywall crack running up from a frame corner usually means the floor below has shifted a little. On its own it is common and often cosmetic. Paired with a sticking door in the same opening, the floor under that opening has probably dropped.
Why do my doors stick or not latch?
When the floor under a door frame drops or lifts, the frame twists out of square and the door rubs at the top or misses the latch. Doors that stick in summer and work again after the fall rain are following the clay. Doors that get steadily worse usually need the slab supported; read about house leveling with piers.
Why does my floor slope or feel bouncy?
On a slab, a slope toward one side or corner usually means that part of the foundation has settled. On a raised floor, a dip or bounce usually means a pier has sunk, a shim has slipped or a beam or joist is sagging. A marble or a phone level app shows the direction. See pier and beam repair.
Why are gaps opening at my baseboards, trim or ceiling?
Trim is fixed to walls, and walls move with the foundation. A gap opening between baseboard and floor, or between wall and ceiling, means part of the structure has dropped or lifted relative to the rest. Measure it, date it and check again after the next change of season.
Why is my floor tile or the slab itself cracking?
Hairline slab cracks from concrete shrinking as it cured are common and rarely serious. A crack that runs through several rows of tile, has one side higher than the other, or keeps widening suggests the slab is bending as the soil below it moves unevenly. That calls for an elevation survey, not just new grout.
Why is the soil pulling away from my slab?
That gap is clay shrinking as it dries. With about 122 days a year at 90°F or more (NOAA), it is common here by late summer, and much of Bexar County's soil is rated for high shrink-swell (USDA NRCS). The gap itself isn't damage, but it shows the soil at your slab edge is moving. The clay and drought guide covers what to do. Typical repair prices are in the San Antonio foundation cost guide.
Which foundation warning signs need a call soon?
Call when signs cluster in one part of the house, when a crack keeps widening month after month, or when doors that used to stick seasonally now stick all year. Those patterns usually mean the foundation is still moving, and earlier repairs tend to be smaller ones.
Have someone look at the house
Tell us what you have noticed and where: the crack, the door, the floor. One independent foundation specialist who works in San Antonio will phone you to talk it over and set a time to see it.