Waterproofing is a must for almost every building project. If not properly sealed, buildings will allow moisture to seep into materials, where it can become trapped. If this moisture does not drain properly, it can cause rotting, damage and mold. This is why it’s important to properly waterproof stucco. So the answer to the question above is “yes,”, you should waterproof your stucco. However, we have a few cautions. Waterproofing stucco is more complex than many homeowners or builders believe. It’s more than slapping a coat of waterproofing on the exterior. Proper waterproofing of stucco is a three-part process that requires in-depth construction knowledge. Following is an overview of these three components.


The drainage matrix is also known as an air gap or drainage mat. This matrix lets trapped water to drain from the structure. It makes sure that moisture does not get trapped in the wall by providing a pathway for draining and an air gap for evaporation. The gap also lowers the risk of moisture spreading between layers. Working in combination with the weather resistant barrier, the drainage matrix is an effective design to waterproof stucco.


To create a waterproof stucco finish, builders should use a multi-layer method. A stucco wall should include a single layer of weather-resistant barrier, a 3D plastic drainage matrix, a metal or fiberglass mat and three layers of stucco. The weather resistant barrier is not enough alone to waterproof the building. It’s important to include a way for the moisture to drain, which is what the matrix should do.


With these structural components put in place, moisture can still gain access behind the stucco. How is that possible? Openings in the stucco wall offer points of entry. Any openings around windows are susceptible to moisture. This makes the use of metal flashing a must. This flashing must be properly installed around all doors and windows where they meet the stucco. This will form a watertight seal. Layers of water-resistant barrier should also be used beneath the bottom window flanges and on the sides. Kick-out flashing must be used for roof and stucco intersections. This will prevent water intrusion at the opening. The use of a water-resistant barrier is also recommended at the top of the stucco walls. Rain gutters provide extra protection.


It is highly recommended that this job be left to the professionals because of the complexity of the structure and the importance of waterproofing stucco. Homeowners who try to finish this waterproofing as a DIY job run the risk of letting moisture into their home, which will have serious long-term consequences.


If you need to waterproof your stucco, the experts at Adco Roofing & Waterproofing are ready to assist you. With in-depth knowledge of waterproofing and extensive experience in the industry, our team will ensure your project gets done right the first time. Contact us today to get started!  

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