Mold is caused by moisture. We seem to have more mold today but we have always had moisture and water. Houses have always been built in the rain around Vancouver. After all it is raining most of the time in the Lower Mainland. Why do we seem to have more mold problems in new construction? Why do new houses go moldy when an old house often don’t?
The problem with new construction is two fold. First the water cannot escape. We have more insulation, tighter seals and vapour barriers. This allows moisture and humidity to be trapped inside the building. We are constantly generating moisture and humidity living in our houses. As new building materials dry they create humidity, as we breath, shower or cook we create humidity. Our plants and pets create humidity. Humidity condenses on cold surfaces. There is no getting around it, we produce humidity in our homes and our homes trap the humidity inside.
The second part of the problem is the materials a house is built from. Yes we know houses have always been built out of wood right? Well, yes but we are not exactly using the same wood as we used to. Remember plywood? Today in much of new construction plywood is replaced with OSB. Cabinets are made out particle board not timber. With timber or plywood moisture and mold cannot get into the surface as easily. OSB and particle board are more porous and act like a sponge to moisture and allow mold spores to penetrate easily. When condensation forms on OSB it turns to mold very quickly.
When these new materials do grow mold the methods for removal are different. In the past wood could be sanded or even wiped to remove mold contamination. Not with OSB or particle board. The mold penetrates deep inside. Fortunately there are processes available to clean these materials but the methods and chemicals are much different. Only those experienced with dealing with these materials should do so otherwise a more costly replacement is necessary.
What can be done to prevent mold problems in new houses? The first step takes place when building the house. The builder must pay closer attention to drying the house properly prior to sealing it up. We know it will get wet during construction so drying is almost always necessary. There is less room for error with the new wood products such as OSB that will go moldy easier and the tighter building seals that will not allow the moisture to escape.
The next step is to control the humidity. If humidity is too high, mold will grow. It doesn’t matter if it is your crawl space, attic, basement or your main living areas humidity must be checked to ensure it is not too high. Condensation on OSB will turn to mold very quickly.
Another important development to help prevent mold growth in new houses is to treat the wood products with permanent antimicrobial penetrants. This will help the OSB or particle board resist mold growth even if it gets wet. This is also an important part of proper mold remediation when wood products are involved.
ABM Environmental can help detect mold, humidity and condensation problems in houses. We also provide treatments to prevent mold in the first place. We specialize in mold treatments and prevention on OSB and other materials used in new construction. Please visit our website home page for more information.