Roof rot is a serious roof condition that affects all kinds of roofs and should be avoided as much as possible. In this blog, roofing company Mobley Brothers Roofing & Restoration takes a closer look at what causes roof rot and how to prevent it from happening to a flat roof.
The Causes of Roof Rot
Roof rot is a form of dry rot that affects the wooden components on a roof. On flat roofs, this includes structural components such as the substrate. Excess unvented moisture encourages wood rot on a roof by allowing wood-destroying fungi to grow on the wood parts. The most well-known species of these fungi is Serpula lacrymans, recognized for its mass of cotton wool-like growth.
Serpula lacrymans thrives in minimal moisture levels, which means the substrate doesn’t have to be soaked for it to grow (hence the term “dry” rot). Other dry rot fungi such as Coniophora puteana (cellar fungus) and Poria vaillantii (pore or mine fungus) may also grow in the same conditions. As the fungi “blossoms,” it sends out microscopic strands that split wood fibers, resulting in soft wood.
Signs of Roof Rot
Roofing contractors like us keep an eye on certain signs that indicate roof rot. A perfectly level roof plane may start sagging in spots, which are not as easy to detect if the roof has loose-laid single-ply material on it. Indoor signs are similar to roof leaks. Water stains on the ceiling immediately under the roof and water streaks down the walls that may extend a few floors down are just two of the most common signs.
Preventing Roof Rot
Moisture on the roofing substrate comes from leaks. Single-ply roofs are more vulnerable to leaks since these roofs are easily punctured. Regular inspections, scheduled maintenance and timely repairs can go a long way in minimizing moisture intrusion through punctures. Reducing foot traffic on such roofs—or investing in built-up roofing if it’s an option—can help minimize risks of roofing puncture. Addressing issues such as ponding water can also lessen further leaks.
A less common source of moisture comes from indoor spaces. Improper ventilation, lack of humidity control and improperly repaired roof leaks can allow moisture to collect on the substrate. Using active humidifier/dehumidifier systems, properly sizing the HVAC systems, and venting indoor moisture sources such as bathrooms and kitchens can help reduce the risks of roof rot.
Mobley Brothers Roofing & Restoration is the roofing company to turn to for all your residential and commercial roofing needs. Give us a call at (615) 645-4500 (Nashville) and (865) 248-2772 (Knoxville) or fill out our contact form. We serve customers in Lebanon and Knoxville, TN.