MOLD! Uh oh, did someone say MOLD? RUN! Yes, the word “mold” is a big buzz word in today’s litigious society. Mold is much more of a hot button topic today than in decades past. So what’s the concern with mold? Mold is symptom of a moisture problem in the building, and continued moisture problems could lead to deterioration of building materials and indoor air quality concerns. Additionally, some people with allergies are sensitive to some molds.

Mold on gypsum sheath

Figure 1: Mold growth on the backside of exterior gypsum sheathing at an apartment complex in Denver, Colorado

Mold is a type of fungi and needs four items to grow: oxygen, food source, warmth, and moisture. So, as long as we cut out one of the four items, we can stop mold growth. Well, it’s hard to cut out oxygen since it is present everywhere. Buildings are built with food that mold loves, including wood, paper, carpet, and drywall, and unless we are going to start building buildings out of nothing but concrete and steel, then let’s not focus on the building materials. We as humans like warmth, so let’s keep our buildings (and our mold) warm. That just leaves moisture. Ah yes, moisture, we can control that. If we can control the moisture, we can control the mold!

Fungal growth on roof sheathing

Figure 2: Fungal growth on the underside of roof sheathing at a low-slope roof in Steamboat, Colorado

Why do we hear more about mold these days than in the past? Back in the day, we built homes out of load bearing masonry and covered the interior of our walls with lath and cement plaster. Mold doesn’t feed on brick and cement plaster. Now we have homes with wood studs, paper-faced drywall, and OSB exterior sheathing; all great food sources for mold. Energy conservations measures have increased the insulation levels in our homes and made our homes much more air tight. While conservation measures are great for saving energy, tighter homes with increased thermal resistance means that homes tend to dry out more slowly than in the past (not a bad thing, we just need to make sure we are controlling the moisture). The old drafty homes dried out more quickly, but wasted a lot more energy!

Figure 3: Mold growth on drywall behind a shower in Lone Tree, Colorado

Figure 3: Mold growth on drywall behind a shower in Lone Tree, Colorado

Figure 4: Mold growth on floor joists in a crawlspace in Jackson, Wyoming

If you have a case involving a mold claim, give the professionals at Western Engineering a call! We can help! If you’re interested in learning more about mold and the basic building envelope details to limit moisture intrusion, WERC is happy to offer a lunch-n-learn presentation on this subject. Please give us a call!

, ,

No comments yet.

Leave a Reply