Stucco Cracks: When to Worry and How to Repair Them

Stucco is a durable, popular exterior in the Southwest and West. It also cracks, because it is a rigid material on a house that moves with heat, settling and, in some areas, earthquakes. The key is knowing which cracks matter.

Types of cracks

Hairline cracks

Thin as a hair, often in a spider web pattern. Usually caused by shrinkage as the stucco cured. Mostly cosmetic, but over time they can let water in.

Cracks at corners of windows and doors

Diagonal cracks from the corners of openings are common, because stress concentrates there. Watch whether they grow.

Wide or growing cracks

Cracks wider than about an eighth of an inch, cracks that keep growing, or cracks with one side bulging out can point to settling, water damage behind the stucco or structural movement. Have a pro look.

Why water is the real danger

Water that gets behind stucco can rot framing and grow mold without showing on the outside. Signs include stains below cracks, bubbling or soft spots, and musty smells inside. During summer monsoon storms in Arizona, wind driven rain finds every crack.

Repair options

Hairline cracks

• Clean the crack.
• Fill with a flexible, paintable acrylic caulk or stucco patch.
• Paint to match, or apply an elastomeric coating, a thick, flexible paint that bridges small cracks.

Larger cracks

• Widen the crack slightly so the patch can grip.
• Fill with a stucco patching compound in layers.
• Match the texture, then paint.

Matching texture and color is the hardest part. For visible walls, a pro will blend the repair much better.

When to call a pro

• Cracks wider than an eighth of an inch or growing
• Stains, bulges or soft spots
• Many cracks across a wall
• Cracks along with doors sticking or interior drywall cracks

Frequently asked questions

Can I paint over stucco cracks?

Regular paint will not hold a crack closed. Fill the crack first, or use an elastomeric coating that is made to bridge small cracks.

How often should stucco be painted?

Every 5 to 10 years in sunny climates, or when it starts to fade and chalk.

Post your stucco repair job with photos, and local pros will send you bids.