Top Tips for DIY Stucco Repair

by Kevin Smith Author

For centuries, stucco has been used to beautify both the interiors and exteriors of buildings. Not only is stucco durable and long-lasting, but it also provides excellent insulation and offers natural resistance to fire. The surface layer can be customized with a smooth, textured, or stamped finish. Simple repairs can be made easily using a mortar stucco mix that is available at most hardware and home improvement stores, making stucco a great choice for exterior and interior walls.

Types of Stucco Damage

Like any other material, damage to stucco can occur over time or due to a variety of causes. Environmental changes, water leaks, ground shifts, and improperly sealed windows are some of the ways stucco can be damaged. Cracks are the most common type of stucco damage. Hairline cracks are caused by vibrations or normal stresses on the exterior. Diagonal cracks around doorways and window frames may occur as a result of natural seismic movements of the earth. Both hairline and diagonal cracks are usually a DIY project that can be completed using a professional-grade mortar stucco mix. However, if the seam and the stucco do not meet properly, the foam trim cracks or cracks appear in horizontal or vertical line patterns, there could be issues occurring underneath the stucco and may require a professional inspection or repair.

Stucco and Its Construction

Stucco usually consists of three layers: two base coats and one finish coat. The first base coat is the scratch coat, aptly named because it is physically scratched with horizontal marks that allow the second coat to adhere to and help the second layer, the brown coat, cure more effectively. Covering the first coat, the brown coat provides a smooth surface for the top and final coat, the finish coat. Mortar stucco mixes can be used not only in the repair of stucco but also for scratch and brown-coat applications in DIY projects.

Tips for the Best DIY Stucco Repair

The last thing a home or business owner wants is an unsightly stucco repair. A high-strength mortar stucco mix with a psi rating of 1800 is the best choice for this purpose. Look for a mortar material that meets the property requirements of ASTM C1714 and ASM CM270 to ensure the proper compressive strength, water retention, and air content. It’s also wise to choose a product that can be pigmented to match the color of the stucco and avoid unsightly repair jobs.