How to Repair Stucco
Stucco is a popular residential siding material. It's inexpensive and easy to apply over a variety of shapes. Composed of sand, Portland cement, and lime, it contains no chemicals, so it's environmentally friendly. Since it's mineral-based, stucco is fire resistant.
Though stucco is fragile, one of its best qualities is that it is easy to repair. Cracks and holes can be filled with a stucco repair material containing acrylic additives that help the patch respond to surrounding expansion and contraction. While repairs only take minutes, one to three days of curing time is necessary before the patch can be painted.
Before You Begin
When shopping for a stucco patch, choose one that is sanded. Sanded means that the material is 50- to 80-percent calcium carbonate, quartz, limestone, or another mineral. Any product that is specifically called a stucco patch should be sanded. Do not use silicone or caulk.
Repair stucco resulting from damage caused by removed items like house numbers or shutters, cracks due to building settlement or aging, or surface divots from lawn mowers and other user-related or environmental damage.
When to Repair Stucco
Repair cracks and holes in stucco immediately. Damaged stucco may lead to water intrusion. Cracks and holes will enlarge on their own if not repaired.
Apply only on dry surfaces. Do not use stucco repair if rain is predicted within the next 12 hours after the repair. Apply only when the air and surface are above 50°F and below 90°F.
Chipping out loose stucco is necessary for repairing stucco. Wear safety glasses and breathing protection when chipping or scraping stucco.
What You'll Need
Equipment / Tools
- Five-in-one tool
- Putty knife
- Cold chisel
- Narrow wire brush
- Caulking gun
- Sanded acrylic-fortified stucco patch (tube or tub)
How to Repair Cracks in Stucco
Widen and Bevel the Crack
With the cold chisel and hammer, widen the crack in the stucco to about 1/4-inch wide. For narrow cracks, start at the center of the crack and expand it. Finish by beveling the sides of the crack into a V-shape.
For cracks that are already about 1/4-inch wide, maintain the width of the crack toward the bottom but bevel the sides.
Clean the Crack
With the narrow wire brush, brush out the crack in the stucco to loosen and remove remaining particles. Brush in the direction of the crack. Brush off peeling paint on the side of the crack.
Apply Stucco Patch
With scissors or a utility knife, cut the tip of the tube of stucco patch at an angle. Starting at one end of the crack and working to its opposite end, squirt the stucco patch into the crack. Apply enough patch that it bulges about 1/4-inch above the stucco surface.
Texture Stucco Patch
With the flat side of the putty knife, push the stucco patch into the crack. Swipe the knife away from the crack to work the excess into the surrounding stucco. Create swirls or half-circles in the stucco patch to match the surrounding area, if needed.
Paint Stucco Patch
Wait at least 24 hours before painting the stucco patch.
How to Repair Holes in Stucco
Clean Hole in Stucco
With the five-in-one tool, clean off the edges of the hole. Remove any debris that may have become lodged in the hole.
Brush Around Hole in Stucco
With the wire brush, clean about 5 inches around the hole. Remove any loose flakes of paint. Clean off dust on the stucco so the stucco patch will stick better.
Patch Hole in Stucco
Scoop a small amount of stucco patch on the putty knife. Force the patch material into the hole. Smooth the material but leave a slight bulge.
Texture Stucco Patch
With the putty knife, create streaks and swirls in the patch material to match texture, if any, in the surrounding stucco. Use the excess material in the bulge to swipe away from the hole and blend into surrounding stucco.
Paint Stucco Patch
Patches in stucco holes require a longer curing time than patches in cracks. Wait at least 72 hours before painting over the stucco patch.
When to Call a Professional
For large cracks in stucco, large missing pieces, large holes, or for extensive damage, call a professional painter to repair the stucco and paint the cured patch material. If stucco siding is prevalent in your area, most professional painters should be able to perform these repairs. If not, talk to the painting company first to see if they are experienced at repairing stucco.
Stucco FAQs. Portland Cement Association