Southeast Pennsylvania has been severely hit with extensive issues involving stucco siding. Initially thought to be merely cosmetic issues, it has been discovered that there are massive cases of wall rot hidden behind the stucco walls. While many people assume this is only an issue for older homes, experts have reported cases of wall rot behind stucco that was installed as recently as six years ago. And this epidemic shows no signs of abating. So what is causing these problems?
The problem begins during the installation of the stucco. A quality stucco installation involves the use of several layers, including asphalt paper, a rain barrier with a permanent air gap, a layer of mesh, and then layers of the stucco itself. Around exterior windows and doors, flashing must be properly installed to achieve a watertight seal. If a contractor is in too big of a hurry or is cutting corners to save on costs, the stucco installation may not be watertight. Add to that the naturally absorbent nature of stucco, and you have a recipe for disaster. This is primary cause of the stucco siding problems facing southeast Pennsylvania.
Issues with Trapped Moisture
When moisture gets trapped behind the stucco, it’s usually not apparent until it has progressed to the point of causing damage. That trapped moisture begins to do quite a few things behind the stucco. One effect referred to as “stucco tears,” which result in discoloration of the stucco beneath windows. Another type of damage caused by this trapped moisture is the formation of mold and mildew, which can escalate into an infestation of black mold.
The worst problem, and the one that is so critical in Pennsylvania, is wall rot. The moisture leads to severe rotting of the various layers that make up the walls of your home, including the OSB sheathing and 2x4s. Some people have reported such severe cases of rot that the walls of their home have essentially turned to mush and have actually become unable to provide support and shelter.
Preventing Moisture Intrusion
The vast majority of this rot is caused by moisture in the form of rain. They key to preventing rot, therefore, is keeping the moisture out. First, stucco should be installed with rain barrier. Next, if windows and doorways are not installed with proper flashing and appropriate layers of paper, then problems are going to start. Other problematic areas include where the lower part of the roof cornice stops in the middle of a stucco wall or if the roof line does not extend below the while. This type of situation requires kick-out flashing to prevent water from getting inside.
Weep screeds should be used at the bottom of the stucco to allow trapped water to drain, and stucco should never be installed below ground level. Gutters should be used to move the water away from problem areas, but they must be kept clean to do their job well. Of course, protection against wall rot begins with a quality stucco installation that takes all of these things into account.
As a homeowner, there are some steps that you can take to prevent moisture intrusion. Avoid placing trees and plants in areas that will come in contact with the stucco. This can create a pocket that traps moisture. Never use a pressure washer to clean discolored stucco. In all likelihood, the discoloration is the result of moisture intrusion and the use of a pressure washer will only exacerbate the problem.
Checking for Problems
While most of the wall rot damage is hidden from the eye, there are tell-tale signs that you can look for, such as “stucco tears” and other areas of discoloration. Look for brown streaks around windows and at the intersections of walls and roofs. Inside the house you can check for wet carpet at the baseboard and be aware of a moldy, musty smell.
Dealing with the Problem
The good news is that you can get your home inspected for this type of damage and deal with it before it escalates. There are services that perform moisture tests and/or inspections (we recommend those that use infrared equipment), and if problems are detected they can be repaired before things get worse. Repairs can range from basic resurfacing to extreme cases that necessitate tearing down the walls to the studs. The more quickly you discover the problem, the less damage you will have to deal with.
If you live in an area that is plagued with stucco-related wall rot, don’t take for granted that your stucco home is fine. Get an inspection done, and, if needed, address any issues that are discovered. The longer moisture intrusion is allowed to progress unchecked, the more severe the damage. A matter of just a few years can mean the difference between thousands of dollars in repairs and tens or even hundreds of thousands of dollars in repairs.
Here at McNamara Masonry, we can inspect your home for moisture damage and perform high-quality stucco resurfacing with our six-layer approach that prevents the intrusion of moisture – and we won’t stop until you are 100% satisfied with our work. We are very experienced with the problems associated with stucco in Pennsylvania and are confident that we can help you.