Stucco Installation Requires Skill and Precision
Dryvit Stucco Installation is a complex project that requires skill and precision. It also requires careful consideration of building codes and the conditions that prevail in your area.
Any underlying issues can wreak havoc with your new exterior stucco and compromise the structural integrity of your home. That’s why stucco contractors carefully inspect your property for potential problems.
Stucco is a versatile material that provides insulation and protects buildings from the elements. It is also durable and, if installed correctly, it can last for generations. There are a few different types of stucco, including traditional one- or three-coat hard coat stucco and a newer system called EIFS (synthetic stucco). While all types are durable, each requires a specific mix of materials to perform properly.
Before the first layer of stucco can be applied, all underlying structures must be properly prepared and inspected. This could involve installing a water-resistant barrier and metal or wire mesh lath for traditional application, or a foam insulation board if using EIFS.
Then the substrate layer, or base coat, is installed. This layer can be made of a concrete or Portland cement based product, or it can be a cement and lime mixture. It should be misted with clean water periodically to prevent rapid drying, which can result in cracking and weakening of the base coat.
Next, the scratch coat is applied to the surface of the base coat. This is a mixture of sand, cement, and reinforcing fibers that is applied to the lath. The surface of the scratch coat is then scuffed horizontally to create a rough surface that will help the next layer, the brown coat, adhere.
A brown coat is then applied over the scratch coat and misted with clean water to prevent rapid drying. This coating is a mixture of the same sand, cement, and reinforcing fibres as the scratch coat, but it is not scuffed. Its purpose is to provide strength to the stucco, and it should be allowed to cure thoroughly before applying the final finish coat.
The final finishing process involves applying a coat of plaster, which is usually hand-troweled to produce a texture that can be smooth or textured. If desired, pigment may be added to the stucco mixture before application to add color. Finally, the finished stucco is protected with a paint or stain to preserve it for years to come. Stucco is a versatile and durable building material that can be installed over wood, brick or concrete to make your home more attractive. If you are interested in learning more about the process or how to apply it, Lowe’s offers a number of resources and can connect you with qualified professionals for a free consultation.
Preparation
A stucco contractor will follow a multi-step process for prepping the substrate of a building. This process includes inspecting and repairing studs, headers, framing members and insulation to ensure they are ready for the stucco application. It also involves installing a moisture barrier and creating control joints.
Moisture barriers are necessary to protect the wall sheathing from damage and to prevent water leaks into the building. They are required by most local building codes, though specific requirements vary based on climate and wall assembly type. The first step in a typical moisture barrier is to hang a double layer of building paper. Start at the bottom of the wall and overlap each sheet by at least four inches over the one below it. Overlap vertical seams by six inches or more, and wrap the paper around corners. Make sure to fasten the papers with galvanized nails or staples. You’ll also need to install any trim accessories such as casing beads, which should be fastened with galvanized nails. Another important accessory is a weep screed, which should be installed along the bottom of each wall to allow moisture that collects behind the stucco to drain out and avoid causing damage to the wood framing underneath.
Next, a scratch coat is applied to the surface of the building facade. This rough surface provides a base for the subsequent stucco layers and helps to provide a key to the underlying structure. It’s important to have a skilled contractor apply this coat properly, because if it is not done correctly the entire project will be compromised.
Once the scratch coat has dried, a second coat is applied. This coating is called the brown coat, and it provides a more refined texture to the wall surface. It can be texturized or made smooth, and it’s often hand-troweled by the contractor to create the desired look. It’s also an opportunity to add color, as the brown coat can be tinted with pigment prior to application.
A final finish coat is then applied to the stucco surface. This final coat can be textured or made smooth, and it’s often tinted to match the color of the walls. The final coat is then left to dry, which can take a few days, depending on the conditions and other variables.
Application
Stucco needs to be applied in a certain way in order to ensure that it sticks to the surface and stays on. The national standard for traditional stucco application is found in ASTM C 926, which defines the requirements for mix portions, application and curing. In wood frame construction, the typical stucco application consists of a scratch coat, brown coat and finish coat for a total thickness of 7/8-inch. The International Residential Code requires a minimum of that thickness. Alternative methods of applying stucco have been recognized by the ICC Evaluation Service and may be used in wood frame construction. These alternative materials must be shown on the plans and approved by the building official.
In order to ensure that the stucco adheres properly to the sheathing, it is necessary to properly lath the walls. This can be done with either all-veneer plywood or oriented strand board. In addition, horizontal blocking is recommended along the studs to increase wall stiffness and reduce the possibility of movement in the sheathing. It is also essential to ensure that a sufficient gap exists between the sheathing and framing in order to facilitate moisture drainage.
It is important to ensure that the sheathing is sprayed with a water repellent prior to the scratch coat being applied. This will help to prevent moisture from penetrating the sheathing, which can cause rot and mold. A good quality primer should also be applied to the sheathing to help keep it from absorbing too much water.
A reputable stucco contractor will spray the entire surface of your home with the proper water repellent, ensuring that the sheathing is completely protected. In addition, they will use a brush to sweep off the loose particles of dirt that are left behind by the paint. This will make sure that your stucco is in the best condition possible and will help to protect it from future damage.
Another advantage of using stucco is that it can be painted in a wide variety of colors and textures. This can give your house a unique look and will add to its curb appeal. It is also an environmentally friendly material and can be recycled. Additionally, it is very easy to maintain and can withstand a lot of weather conditions. It is also resistant to fire, mold, rot, and termite infestations.
Finish
Stucco is a durable and long-lasting material for exterior walls. It’s an excellent choice for insulating your home from extreme temperatures and can be molded to create different textures. It’s also a great option for preserving the historic look of your home. Stucco requires regular maintenance to keep it free of voids. Voids are an invitation for moisture, rodents, and other natural hazards to enter your home. It’s important to keep up with the maintenance and inspections to avoid costly repairs.
Stucco can be applied to wood sheathing, masonry, or brick. If applying to sheathing, it is recommended that a double layer of grade-D waterproof building paper be applied to the sheathing before installing the stucco. Metal lath is then fastened to the sheathing to support the stucco. Three separate coats are then applied, known as the scratch coat, brown coat, and finish coat. If you are using a concrete masonry sheath or brick that is in good condition, the brown coat may be skipped and straight to the finish coat.
Once the scratch coat has cured to the point where your thumbprint remains in the surface, horizontal grooves are created with a racking tool or notched trowel. This makes sure that the next coats of stucco will adhere properly to the wall. This is an essential step, because the next coatings must be free of contaminants that inhibit bonding. The contractor will use a wire brush to remove any dirt or other debris from the substrate.
The brown coat is then brushed on the wall. This layer acts as a strengthening coat and must be allowed to cure for at least 36 hours. It should be misted with water periodically to prevent rapid drying, which can cause the stucco to become brittle.
Once cured, the finish coat is hand-troweled and texturized or made into a smooth surface. Pigment can be added to this layer to achieve a variety of colors. It is recommended to use acrylic latex paint as opposed to oil-based primers or paints.
In addition to these steps, a stucco contractor will install expansion joints in the corners and anywhere there are changes in the wall thickness. These will help to reduce cracking as the wall expands and contracts with seasonal temperature fluctuations.