Stucco siding is a type of exterior wall cladding made of a mixture of Portland cement, sand, water, and lime. There may be additives used to help hold the mix together, make it more plastic, or speed up or slow down the setting time.
Stucco is often applied to a metal lath or reinforcement that is secured to a wall over building paper (felt paper, sheathing paper, or building felt). Edges may be protected with metal trim pieces. Rough masonry surfaces don’t use lath or building paper, stucco is applied directly to the masonry surface.
Metal trim pieces such as casing beads, control joints, drip screed, inside corners, and external corners should be corrosion resistant metals. These pieces provide finished edges and protect vulnerable areas.
Common problems associated with Stucco are:
· Cracks, crumbling, loose or bulging.
· Incompatible flashings.
· Mechanical damage.
· No drip screed.
Cracks, crumbling, loose or bulging
Compared with stucco over masonry or concrete, stucco over wood frame is more vulnerable to cracking as a result of both impact and shrinkage/expansion from changes in temperature and moisture. These defects in stucco may only be siding failures, or they may be related to structural movement. Control joints help to minimize these defects but are more often missing or not ideally located. The implications of stucco that is not watertight include water damage to the wood building structure and interior finishes. Moisture intrusion can lead to mold, mildew growth, rot and structural damage.
Incompatible Flashings
Aluminum flashing should not be installed in contact with stucco. The aluminum is prone is oxidation (rusting). Aluminum must be coated or separated by another material to prevent corrosion. Flashing will fail as the corrode, and the expansion of the corroding metal may cause the stucco to crack and eventually fall off leading to moisture intrusion.
Mechanical Damage
Stucco applied over wood framing is more susceptible to mechanical damage as compared to stucco applied over masonry or concrete. Most common location is the high-traffic areas like garage and exterior doors. Immediate repairs should be carried out whenever a damaged stucco is encountered.
No Drip Screed
Stucco should terminate 6 inches above grade or 2 inches above a paved surface. There should be a drip screed installed at the bottom. The drip screed is a metal stop that is exposed below the stucco. This provides a finished edge, allows drainage, and prevents water from being drawn up into the wall. Absence of drip screed can lead to water being drawn up into the wall or water can accumulate over the bottom portion of the stucco leading to numerous issues.
Following steps are recommended to maintain stucco siding and prevent common problems:
1. Cleaning: Clean stucco periodically with a soft brush and mild soap and water solution. Avoid using pressure washers, as they can cause damage to the stucco surface.
2. Repainting: Re-paint stucco every 5-10 years to refresh its color and protect it from fading and weather damage.
3. Inspecting: Regularly inspect stucco for cracks, peeling, or chipping and address any damage promptly to prevent further deterioration.
4. Flashing maintenance: Ensure that the flashing around windows, doors, and other openings is properly installed and in good condition to prevent water damage.
5. Water management: Ensure proper water drainage around the foundation of the building to prevent moisture from accumulating against the stucco.
6. Caulking: Caulk any cracks or gaps in the stucco to prevent water from entering and causing damage.
7. Professional maintenance: Have a professional inspect and maintain the stucco siding every 2-3 years to ensure its durability and longevity.
Contact Bryan & Bryan Inspections today by calling (866) 484-8318 or schedule a home inspection now. We also offer mold inspections, commercial inspections, stucco services, new construction inspections, and more.