Michelle Garcia | November 16th, 2021
You may have heard of stucco as an excellent finish for houses. However, several people do not understand how stucco works. This article aims to discuss the application, installation, and repair of stucco. I hope you find this piece useful!
How is stucco applied and installed on houses?
Stucco is applied in three layers to maintain its integrity. They include the structural base, base coats, and finishing coats. The structural base is the first layer, which is very important in preserving the integrity of the stucco system.
Traditional stucco may crack easily hence the need for reinforcement. A metal lath system is a preferred choice for this situation. It is a sheet of metal with diamond holes resembling a mesh. The metal lath is flexible and can be nailed onto concrete walls. Its unique function is the provision of a structurally stable background that allows the adhesion of stucco. It also prevents cracking and flexing of the stucco.
The base coat is the next layer of stucco that you have to apply. It comprises two layers- the scratch coat and the brown coat. The scratch coat is made from cement and sand. It is applied directly to the metal lath.
This layer is coarse to ensure the next layer of stucco adheres properly. The brown coat is the next layer of stucco to be applied. It is spread evenly over the scratch coat. It is then allowed to cure for about 7 days.
The surface may require wetting to promote adequate curing. Water from a hose is sprayed onto the surface of the stucco under controlled pressure.
The final layer is the finish coat, which is applied to the base coat after curing it. The finish coat varies depending on the color and texture you desire for your wall. Two types of stucco can be used as a finish coat. Cement-based stucco is cheaper but requires manual mixing and comes in various textures and colors. On the other hand, acrylic-based stuccos are premixed and a more expensive option for the finish coat.
Generally, the stucco installation process is similar for homes and commercial buildings. Commercial buildings are often reinforced with traditional stucco and EIFS (External Insulation and Finishing Systems). The EIFS is installed with a layer of synthetic stucco. The first layer in commercial buildings includes a polystyrene foam board. This foam board is useful in insulating a building.
The next step is the application of a fiberglass mesh, which promotes the stability of stucco. The finishing coat is then applied to the building. EIFS is more durable because of the fiberglass layer.
It is lighter and easier to customize than traditional stucco. However, the installation of EIFS is more expensive in terms of time and money. Moreso, it is more fragile than traditional stucco.
Stucco is essentially made from cement, water, sand, and lime. Modern stucco favors the use of Portland cement, sand, lime, and water. Some stucco forms are mixed with acrylics or glass fibers as reinforcements to increase its stability. Learn more about how stucco is made.
In constructing the house, the stucco installation begins only after the bricklayers are 100% through with their work. Before commencing the application of stucco, define the color- ensure the color matches the brick and roof.
Get different samples to determine which color suits the type of house. You may also need to consider the different profiles on the house around the window casing, door frames, or freeze boards. The finishing texture of the stucco is another important aspect in preparation for building stucco houses.
In addition, it is important to check the weather to ensure it is not going to rain as this does not favor stucco installation. You may need to delay stucco installation if the temperature drops below 4 degrees Celsius (39.2 degrees Fahrenheit) or increases above 32 degrees Celsius (89.6 degrees Fahrenheit).
The next step is to cover the sheathing material (usually wood) with building paper. Install weep screeds and casing bead for better water drainage. You can now attach the metal lath and install control joints to create separate panels.
The next step is the application of the scratch coat onto the metal lath. Allow this layer to cure for about 2 days but continue irrigating it to prevent drying out. You can now apply the brown coat, which should be allowed to cure for 7 days.
Remember to wet it to promote proper curing. After the brown coat is properly cured, you can apply the finish coat and paint the stucco.
Stucco is a durable finish that can last several decades. However, routine repairs are necessary to maintain its integrity. The first step in stucco repairs is to identify the underlying cause of the damage. Damage stucco often looks loose and bulgy. You can use a chisel to outline the damaged areas.
Remove the loose areas with caution to avoid pulling off certain sections of the wall. Remove only the area you can repair at a time to avoid unnecessary exposure. If there is a metal lath, use metal snips to cut it out. Then remove the lath from the wall by removing all nails.
The second stage involves the use of grade D building paper to cover the exposed area. This layer is critical to provide a moisture barrier. The third stage is the installation of the metal lath. It should be positioned on the building paper and fastened with suitable nails. The nails should be able to penetrate the sheathing for proper adherence.
The fourth stage involves mixing the stucco. Do not mix more than you need and follow the manufacturer’s instructions. You can mix with a mortar mixer if you need a large stucco or a simple drill.
Do not mix the stucco under direct sunlight, as this can cause it to harden too fast. The average drying time for stucco is 45 minutes. Hence, ensure you use up the mixed stucco before this time.
The next stage is the application of the scratch coat. In this stage, you apply the mixed stucco onto the metal lath. Repeat the process until the area is completely covered with stucco.
Then, smoothen it out to produce an even surface. Ensure you carefully apply the new stucco along the edges of the old layer to promote bonding. Then scratch the surface to make it rough.
The sixth stage involves the application of the brown coat. Let it cure according to the manufacturer’s instructions. Finally, it is time to apply the final coat. Ensure the finishing matches the original one. Let the stucco cure, and you can paint it to even out any edges if needed.
Stucco repair contractors are professionals who have experience and training with the installation and repair of stucco. Most stucco plasterers do not need advanced qualifications; a high school or GED certificate will suffice. However, several years of training under an expert is necessary to absorb the skills. Every reputable construction company should have a stucco plasterer who can get the job done- installing, tearing down, or repairing stucco.
You can repair stucco yourself if you have the necessary skill, equipment, and knowledge to install it. However, hiring a professional is the safest choice.
Stucco is a finish that has been used for several decades since the Roman Empire. It is durable and can last well over 50 years, given correct installment and maintenance.
It is not advisable to use stucco in areas that are prone to heavy rainfall or snow. Stucco is fairly water-resistant. However, excess moisture can lead to its damage.
Stucco has excellent insulating properties. It offers various textures and can be used on several surfaces. One great perk of stucco is that it is not expensive to maintain.