Here in Hawaii, stucco is a popular home exterior finish – and for good reasons. It’s durable, cost-effective, attractive, and virtually maintenance-free.
Stucco is also water-resistant, which is good in our climate. However, it’s not water-proof, and it is possible for the material to become water damaged.
Typically, early signs of stucco water damage are bumps appearing on the surface. It’s important to address the water damage quickly before the exterior of the home deteriorates or mold grows behind the stucco.
Common causes of stucco water damage
- Incorrect mixture. Stucco is made from a very specific mixture of Portland cement, sand, and water. If the combination is not balanced or mixed correctly, the strength and durability of the final product will suffer.
- Faulty installation. At the same time, if the stucco is not installed correctly, it can lead to problems down the road. The stucco mixture requires ample time to cure, and three coats are required for proper installation.
- Stress cracks. If the building shifts or moves from something hitting it, an earthquake, or strong winds, the force can cause cracks in the stucco. Water can find its way into these cracks and get between the walls.
- Improper flashing. Flashing is used to protect any steams of the stucco. If the flashing is not installed properly, or the material (usually a metal like aluminum) is damaged or corrodes, then water can seep through.
Repairing water-damaged stucco
The first step is taking care of the root cause of the water damage. For example, if you have a leaky pipe behind the wall, that must be addressed so the damage doesn’t occur again.
Next, you’ll need to remove the damaged stucco material, just like you would with rotted wood or damaged drywall. To patch the area, you’ll need to mix the stucco ingredients in a bucket to the right consistency. Using a notched trowel, you’ll apply the stucco mixture on the wall. As mentioned before, three coats of stucco are necessary with drying periods in between.
If hiring a professional to repair the stucco, costs will vary based on the amount and extent of the water damage. There are also approaches to prevent future water damage, including installing drainage plane material behind the stucco or applying sealants to the surface.