Why is brick pulling away from my window or door frame?

Reviewed by Preston, Oklahoma foundation repair consultant · Updated 2026-10-14

In short: When brick veneer pulls away from a window or door frame, the usual reason is that the edge of the foundation carrying the brick has dropped. On Oklahoma's expansive clay, this often happens when soil at the perimeter dries and shrinks. The gap tends to be widest in late summer and in drought years.

Why does the gap open?

Brick veneer is a single layer of brick tied to the wood-framed wall behind it and resting on a ledge at the edge of the foundation. Windows and doors are attached to the wood framing. When the foundation edge settles, the brick goes down with it, but the frame does not follow in the same way, so the brick separates from the side or top of the frame.

On shrinkable clay, drying soil contracts and the building can sink, often cracking around windows and doors ¹. Cracks usually need about 5 to 10 millimeters (roughly 1/4 to 3/8 inch) of movement before they show ¹.

Edge drop on expansive clay

The mechanism this site links to this sign is perimeter drying settlement (edge drop):

1. Soil just outside the foundation dries in hot, dry weather.
2. The clay shrinks and the outer beam settles relative to the interior.
3. Brick and openings along that wall distort.

Engineering guidance on expansive soil notes that lack of watering during drought, which dries out the clay, could be more damaging than overwatering ³. Texas slab monitoring found out-of-levelness growing from about 2-1/4 to 3-3/4 inches on average as the growing season progressed, with droughts making settlement worse and winter rain allowing partial recovery ².

How do Oklahoma soils cause it?

More than 75% of Oklahoma has bedrock that can produce expansive soils, and clay-rich shales can swell to 1.5 to 2 times their dry volume when wet ⁵. Soil surveys rate this with linear extensibility; above 3%, shrinking and swelling can damage buildings and special design is commonly needed ⁶. Dry-season cracks in expansive clay can be about an inch wide at the surface, and one documented crack ran at least 32 inches deep ⁴. See shrink-swell and the active zone and the soil series index.

What else should you look for?

Separation at frames rarely appears alone. Check the same wall for:

• Stair-step brick cracks wider at the top, which point toward a dropping corner or edge.
• Frieze board or trim separation at the top of the brick.
• Windows sticking or cracked glass in the affected openings.
• Soil pulled away from the foundation, a sign of drying at the perimeter.

Home inspection standards list brick cracks, drywall cracks, out-of-square door frames and uneven floors as signs of possible foundation movement to report ⁷.

How do you document it?

• Measure gap width at the same points on each frame, top and sides.
• Photograph each gap with a ruler or crack gauge in view.
• Repeat every month or two through at least one summer and winter.
• Plot the locations on a floor plan with an elevation survey to see which corner or edge is low.

A gap that widens in late summer and narrows in wet months points toward moisture-driven soil movement; see cracks that open and close seasonally.

What are the next steps?

Plot the sign on an elevation survey, compare it with the patterns in the distress pattern library, and use the symptom matrix to weigh likely mechanisms.

Related

• Perimeter drying settlement (edge drop)
• Stair-step brick crack wider at top
• Vertical brick or veneer crack
• Distress pattern library
• Symptom matrix