A properly-built roof should have straight angles. However, some roofs may sag over time, which will have to be fixed by your roofing contractor. In this post, local roof replacement company Burr Roofing, Siding, & Windows shares a look at the common causes of sagging roofs.
1. Water Damage — Once moisture finds its way into the roof support structure, it can cause water damage, resulting in weakened wood, damaged insulation, and mold growth. Sagging is the cumulative effect of moisture making its way to the roof support system. This is one of the reasons why today’s roofing systems have components like underlayment and flashing. A single leak, if not addressed in time, can compromise the roof’s structural integrity.
2. Too Much Weight — There is no room for eyeballing when it comes to building a new roof. A roofing installer should take into account the roof’s slope, the local climate, and what material will be installed on before the final plan is drawn. The new roofing structure has to be able to support most types of roofing materials, from lightweight metal roofing or heavy tile roofing, with headroom for snow and other things that may increase the roofing load. A weak roofing structure will sag or collapse under the weight.
3. Use of Inferior Materials — Unscrupulous roofing installers may substitute inferior materials, such as untreated lumber, to cut roofing costs and give potential clients a lower bid. While roofs made with such materials may hold up for the first few years, exposure to moisture and temperature changes will make their shortcomings apparent.
4. Old Age — Sometimes a roofline will start bowing because it’s simply too old. A typical sloped roofing structure is usually good for two installations, or up to 60 years all told, and only if it’s properly maintained. The older the roof is, the more likely it will begin to sag. Unlike storm or impact damage, a sagging can be anticipated with regular roofing inspections and maintenance appointments.