A roof can sag for a number of reasons, but it is almost always something that you need to look into urgently. A sagging roof doesn't necessarily mean that you need to replace your entire roof, but if left for too long, a sagging roof can get worse and possibly collapse in on itself, causing damage and possibly injury.
If your roof is already sagging it will need to be repaired, but figuring out why it's sagging can help you prevent the issue from happening again:
Your roof can hold a large amount of weight, but constant rain, wind and snow can eventually be too much, especially on an aging roof. Even highly slanted roofs will have this issue. Wind, rain and high heat especially can damage and weak your roof over time, making it more likely that the weight of snow and water will have more of an effect.
If your roof suffers from extreme weather damage, the most you can do is make sure that your gutters and your roof stays clear, and that there are no leaks. If you notice a large buildup of snow, try to clear some of the snow off instead of letting it sit.
A typical roof is designed using a triangle of wood. The ridge board at the very top is met on either side by rafters, and connecting the rafters at the bottom are roof joists. This triangle design means that no matter what side feels pressure, the other two will help support it.
This also means that if any of the angles or beams starts to weaken, the whole roof could start to sag. Heavy weights can slowly push the rafters to the side, which lowers the ridge board. If there are any leaks in your roof, water damage can also weaken the wood and cause it to sag as well.
If the beams themselves are sturdy, the sagging could also be caused by damage in your decking. If the decking itself is damaged by dry rot, infestation or warping, you'll often see what looks like waves.
Make roof inspections a part of your annual maintenance, and make a habit of checking inside your attic to look for early signs of any damage. If the sagging is minor enough, you can often get away with either replacing the decking or reinforcing the rafters. If you need to choose the latter option, you generally won't even need to re-shingle your roof.
On houses more than 50 to 60 years old, your roof may have been built using methods that are no longer adequate. For example, joists and rafters using boards that are too long may be more likely to weaken and bend over time, especially if supported by weak trusses. If this is the case, reinforcing the roof will also fix most sagging problems unless the sagging is severe enough.
While reinforcing your roof can be a DIY project, you should consider hiring a roofing contractor or inspector to look over the damage for you and make recommendations; if there is anything you want a quality job done on, it's your roof. To learn more, contact a company like All American Roofing Incorporated with any questions or concerns you have.Share