Although property owners aren’t necessarily expected to climb on their roofs every season as part of regular home maintenance, some conditions should be monitored to prevent roof damage and help you get the longest life out of your roof-covering materials. Certain types of damage can lead to water and pest intrusion, structural deterioration, and the escape of costly energy.
Weathering
Hail and storm damage, known as weathering, can weaken a roof’s surface even if you haven’t lost any tiles, sheeting, flashing or gutters following a storm. It’s the most common source of environmental damage to roofs. Strong, sustained winds can cause an uplift to the edges of tiles and flashings, weakening their points of attachment and allowing rainwater to reach the roof void. Wind can also send projectiles through the air, which can damage every surface of the home’s exterior, including the roof. You should always inspect your roof after a heavy weather event, as far as it is practical to do so without taking any undue risks, to check whether you have lost any roof-covering materials, or if any parts look particularly weathered or damaged. A small fix now could prevent costly repairs later.
Tree Damage
Tree damage results from wind-blown tree branches scraping against roofing and from the impact of falling branches blown by wind and/or because the nearby tree has dead branches that eventually break off and fall. Branches that overhang the roof should always be cut back to avoid damage from both abrasion and impact and to prevent the accumulation of leaf debris on the roof, its valleys, and in the gutters, which will interfere with proper drainage and lead to the pooling of rainwater. Of course, it’s especially important to ensure that tree limbs near the home’s roof and exterior are safe from utility and power lines. Tree-trimming is a type of property owner maintenance task that should be undertaken by qualified professionals, as it can lead to accidentally cutting off the service or power from an overhead line, being electrocuted by an energised line, being struck by an unsecured tree branch, falling off the roof or a ladder, and any number of similar mishaps that the property owner is not trained to anticipate and avoid.
Animal Damage
Possums, rodents and birds will sometimes tear through roofing when they’re searching for a protected area in which to build nests and raise their young. They often attack the roof’s eaves first, especially on homes that have suffered decay. If you hear any activity of wildlife on your roof, check inside your roof void for evidence of pest intrusion, such as damaged insulation, which pests may use for nesting material. Darkened insulation generally indicates that excess air is blowing through some hole in the structure, leading the insulation to become darkened by dirt or moisture.
Biological Growth
Algae, moss and lichen are types of biological growth that may be found on tiles under certain conditions. Some professionals consider this growth destructive, while others consider it merely a cosmetic problem. Clay and concrete tiles may become discoloured by both algae and moss, which spread by releasing airborne spores.
Almost all biological growth on tiles is related to the long-term presence of excess moisture, which is why these problems are more common in areas with significant rainfall and high relative humidity. But even in dry climates, roofs that are shaded most of the time can develop biological growth.
What we commonly call “algae” is not algae, but a type of bacteria capable of photosynthesis. Algae appear as dark streaks, which are the dark sheaths produced by the organisms to protect themselves from the ultraviolet radiation of the sun. When environmental conditions are right, the problem can spread quickly across a roof.
Algae attach to the tiles by secreting a substance that bonds it tightly to the surface. Growth can be difficult to remove without damaging the roof. The best method is prevention. Algae stains can sometimes be lightened in colour by using special cleaners. Power washing and heavy scrubbing may loosen or dislodge granules. Chemicals used for cleaning tiles may damage landscaping. Also, the cleaning process makes the roof wet and slippery, so such work should be performed by a qualified professional.
Moss is a greenish plant that can grow more thickly than algae. It attaches itself to the roof through a shallow root system that can be freed from tiles easily with a brush. Moss deteriorates tiles by holding moisture against them, but this is a slow process. Moss is mostly a cosmetic issue and, like algae, can create hazardous conditions for those who climb on the roof.
Lichens are composite organisms consisting of a fungus and a photosynthetic partner, such as green or blue-green algae. Lichens bond tightly to the roof, and when they’re removed from tiles, they may take granules with them. Damage from lichen removal can resemble blistering.
Your Red Dog Building Inspections consultant can investigate signs of roof damage or deterioration before you call a roofing contractor. That way, you’ll know exactly what types of problems should be addressed before you break out the chequebook for repairs!
