Dryvit Stucco Installation requires a unique mix of skill, knowledge, and application tools. It is often best to let professionals do the work.
Wood-framed walls need three coats of stucco, including a moisture barrier to minimize sheathing damage and mold growth. Sheathing is typically backed with either plywood or oriented strand board (OSB). The International Residential Code only recommends a water-resistive and vapor-permeable barrier.
Stucco is a highly durable and visually appealing shield that protects the exterior of your home or commercial building from the elements. It requires a complex mixture of materials and applications to achieve the desired thickness and appearance. It’s important to use the right products and follow a thorough application process to ensure the longevity of your stucco surfaces.
Before you can apply stucco to a new or existing structure, it’s critical to make sure the surface is prepared properly. This includes cleaning the area and addressing any structural problems that may arise. A professional stucco contractor will perform a detailed inspection of the surface before proceeding to ensure that everything is ready for the installation of your hardcoat stucco.
The first step in the stucco installation process is to apply a concrete bonding agent to the substrate. This will provide a solid surface for the second layer of stucco to adhere to, and it will also help to strengthen the walls and reduce future cracking. Once the bonding agent has had time to dry, a scratch coat is then applied to the lath. This rough coat, which is made of a mixture of sand and cement, should be left to cure before the brown coat is added.
Once the scratch coat has had an opportunity to dry completely, the brown coat is then applied to the wall. This coat is a thicker mixture that is typically hand-troweled. It is sometimes texturized or colored using pigment, which gives the structure a more aesthetic appearance. This layer is left to cure for about 24 hours, which helps to prevent rapid drying that can cause the stucco to become brittle.
During the stucco application process, it’s important to install trim accessories. This includes casing beads and a corner bead, which protect the corners of the structure and prevent water from leaking into the wall. It’s also important to install weep screeds, which allow moisture that does get into the walls to escape without damaging the wood framing. These are normally installed along the bottom edges of the wall, although it’s possible to use a weep mat or rainscreen instead.
Scratch Coat
The first of three stucco layers is known as the scratch coat, and it provides a rough surface for effective adherence. It consists of a mixture of Portland cement, sand, and reinforcing fibers. A notched trowel or scarifier tool is used to etch horizontal grooves in the scratch coat surface. This not only creates a more attractive texture, but it also makes the material more durable and easier to work with. The textured surface of the scratch coat also facilitates mechanical bonding, meaning that when subsequent stucco layers are applied they will interlock with the ridges.
The scratch coat must dry fully before the brown coat can be added. This typically takes 24-48 hours, depending on the weather. It is important that the time between application of each layer is not rushed. If the curing process is not respected it will lead to cracks in the finish, allowing moisture to penetrate the stucco and damage the structure of the building.
Contractors that are experienced in stucco installation understand the importance of proper timing between layers. This will ensure that the materials bond properly and the project proceeds as planned. Taking the time to allow each layer to set completely will make the difference between a well-performing finish and one that fails due to poor application.
Once the scratch coat is cured, the next layer that needs to be applied is the brown coat. This consists of the same ingredients as the scratch coat, but it is applied with a float instead of using a notched trowel. This helps to produce a smoother and more uniform surface that will act as the base for the final coat. The brown coat is also a good opportunity to eliminate any irregularities in the surface of the wall that may have been caused by the application of the scratch and base coats.
After the brown coat is rubbed down with a float, it must dry for another 24 hours. This allows the brown coat to settle and provide a solid foundation for the final coat of stucco that will be applied. During this time, contractors can use a variety of tools to give the brown coat the desired texture and appearance.
Brown Coat
Stucco is a popular choice for building exteriors because it can be sculpted into a wide variety of designs, and it also resists damage caused by wind, rain, snow and temperature changes. It is important to remember that stucco is a process that requires time, and there are many factors that can impact the timeline of your project. For example, weather is a significant factor in how long it will take to work and cure the product, and your contractor should only start the process when all of the necessary materials are in stock and ready to use. Additionally, the recent COVID-19 pandemic has created a lot of material shortages and delays, so you should be sure to check with your product suppliers before starting any work.
The brown coat is the second of three layers in a traditional plaster or stucco application, and it plays an essential role in providing a durable base for the finish layer. Unlike the scratch coat, which is embedded into lath and wire mesh, the brown coat is applied over a more stable base, such as cement based substrates. The brown coat also serves as a leveling layer that creates a flat surface, which is critical for ensuring that the finish coating achieves the desired smoothness and appearance.
The process for applying the brown coat is similar to that of the scratch coat, with the exception that a higher ratio of sand to cement is used. The sand helps to compact the material, which will lead to a better end result when it is float off. Additionally, the sand helps to provide a mechanical bond with the scratch coat, in addition to the chemical bond that takes place during curing.
After the brown coat is applied, it must be cured for 48 hours before the final phase of the stucco installation is begun. This step is what gives the finished product its texture and color, and it can be accomplished through a number of methods. For example, it is possible to spray the final coat, or it can be hand troweled.
Finish Coat
The final step in the stucco process is applying a layer of finish coat to your exterior wall. This coat gives your home a unique texture and appearance that will protect it from weather and moisture, while adding to its aesthetic appeal.
The stucco process requires expert timing, as each coat must be applied and allowed to set properly before the next one can be used. Rushing the process can lead to poor results, such as cracks or a weaker surface that does not hold up against moisture and harsh weather conditions.
While you can stucco over a variety of materials, it is typically best to put up sheathing before starting the stucco process. The sheathing will help keep the structure stable, and can be wood-sheathed or made from a rigid material such as plywood, oriented strand board (OSB), cement board, or exterior grade gypsum sheathing. Ensure that the sheathing is installed per local building codes. If you are using a wood-sheathed building, be sure to install control joints at every 18 ft (6 m) or as directed by your architect. This will reduce cracking caused by expansion and contraction of the sheathing.
After the brown coat has been sprayed on, it must be left to cure for at least 24 hours. During this time, the surface will become firm and may form small cracks around the corners of the walls and any other areas where different sections meet. The cracks should be wiped down and smoothed to create an even surface for the finish coat to adhere to.
When the brown coat is ready, you can begin to apply the finish coat to your walls. It is important to spray a mist of water over the surface to keep it workable. This is especially important if you are working outdoors, where it can be very hot.
Once the finish coat has been sprayed on, it can be “floated” with a hard rubber float to make it smooth. It is then possible to add a decorative texture, such as light or heavy lace, dash, and others. When you are happy with the look, it can be polished with a trowel to give it a nice, glossy finish.
