Mold requires water. No water, no mold. Mold is the result of a water problem. Fix the water problem, clean up the mold, and you have fixed the mold problem. To avoid mold problems, avoid water problems. Design and build in a manner that reduces water problems.
Mold also requires food. The food it likes best is cellulose-the more processed the better. Mold really likes wet paper. It kind of likes wet wood, but not as much as it likes wet paper. It likes processed wood better than it likes real wood. So mold likes oriented strand board (OSB) better than plywood and plywood better than a stud or a joist. Mold also likes the feces of cock-roaches and dust mites, as well as some pastes, paints and adhesives.
Just because something gets wet, doesn’t mean it will get moldy. It needs to be wet for a while. Wet paper needs to be wet for a couple of days. Wet wood, for a couple of weeks. And it also needs to be warm. Warm, wet paper that is wet for a while is a problem. Because it usually takes time for mold to grow, promptly drying the building after a water event will prevent a mold problem from developing. Of course, make certain that the underlying problem that caused the water problem is also corrected.
Mold, especially mold spores are everywhere outside. Mold is on everything we build with and everything we bring into a building. Remember we build outside. We turn a piece of the “outside” into the inside as the construction process progresses. Therefore mold will also be inside. And remember it’s often wet outside. What’s worse is that construction is also a wet process. If is not possible or practical to have a mold free building. Just like it is not possible to have a mold free outside. We just don’t want a lot of mold inside and we don’t want any mold that is actively growing. We especially don’t want a lot of mold or mold that is growing where you can breathe it. We don’t know how much exposure to mold is necessary to initiate allergic response to mold. Once the allergy has developed, however, exposure to very small amounts of mold can cause symptoms. Asthma affects lots of people, and some molds are triggers for asthma. The mold-asthma connection is really the heart of most of the mold worries.
Source: Building Science Corporation-a report by Joseph Latiburek, Terry Brennan and Nathan Yost-January 2002 (More information will appear in future newsletters)
Submitted by Malcolm Champlain,
Housing Project Manager