Foundation Crack Repair in New Braunfels

Reading brick cracks

Brick veneer is a stiff skin on a house that moves, so it cracks first and tells the story best. The pattern matters more than the crack itself.

Stair-step cracks following the mortar joints diagonally, widening toward the top of the wall or toward one end, are the classic sign of a settled corner or edge. The brick is pulling apart because the foundation under one end has dropped. If the steps are wider than a quarter inch, if the crack has opened since you last looked, or if there is a matching crack on the inside drywall, the foundation is moving and the crack is a symptom.

Vertical cracks running straight through brick and mortar in a line usually mean the wall is too long without a control joint and has cracked from thermal expansion. Common on long garage walls facing west. Usually cosmetic.

Horizontal cracks along a mortar bed, especially near the top of a wall under the soffit, point to the frieze board separating as the wall tilts or the lintel over a wide opening deflecting. Worth having looked at.

A gap opening between the brick and a window or door frame on one side of the house only, with the caulk torn, is a rotation sign and goes with a settled edge.

Drywall and interior cracks

Diagonal cracks running from the upper corners of door and window openings are the interior twin of stair-step brick cracks. The opening is the weak point in the wall, and when the wall racks from foundation movement the crack starts there. One or two in a twenty-year-old house are normal; a cluster on one side of the house with doors sticking is not.

Cracks along the tape joints between drywall sheets, straight and running vertically or horizontally, are usually tape failure or framing shrinkage. Cracks at the ceiling-wall joint on an exterior wall can be truss uplift, a roof framing phenomenon, not the foundation. Nail pops are framing.

On a pier and beam house, cracks in plaster at door corners plus a sloping floor point to a settled or rotted support below that spot.

Slab cracks

A hairline crack running across a garage slab or showing through the tile in a straight line is almost always a shrinkage crack from the original cure. Concrete shrinks as it dries and cracks somewhere. These are cosmetic.

A slab crack where one side is higher than the other, where the crack is wider than an eighth of an inch and growing, or where a ridge has formed under the tile or carpet, is a structural crack. The slab has bent, either because an edge dropped or because the center heaved. On the clay east of I-35, center heave from a plumbing leak or heavy watering produces a long crack down the middle of the house with the tile tented along it.

Cracks at the slab edge visible from outside, especially at a corner, with the brick above also cracked, indicate the grade beam has cracked from settlement.

How cracks are repaired

Structural cracks are not repaired directly. The cause is. Piers are installed under the settled section and the house is lifted, which closes most of the crack. Once the house is stable, the crack itself gets cosmetic treatment.

Brick: cracked mortar joints are ground out and tuck-pointed with matching mortar. Cracked bricks are cut out and replaced. On a good match the repair disappears in a year of weather. Tuck-pointing a typical stair-step crack runs a few hundred dollars; a mason does this, not the foundation crew.

Drywall: the crack is cut back, taped with mesh, floated, textured and painted. Wait two to four weeks after a lift.

Slab: structural cracks in the slab, after the house is stabilized, can be filled with epoxy injection to restore the concrete's continuity and keep moisture out. Shrinkage cracks in a garage can be left alone or sealed with a flexible polyurethane sealant. Epoxy injection runs roughly $250 to $800 per crack.

Cracks that leak water into a living space are a separate issue and usually a drainage problem first.