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The Home Depot

3 Causes of a Sagging Roof

Pro Referral > Home Guides > Roofing > 3 Causes of a Sagging Roof
3 Causes of a Sagging Roof

A sagging roof isn’t just unattractive – it could be a warning that eventually the roof could collapse. A roof can last up to 100 years depending on the building material used. It’s important that the integrity of your home’s roof remain intact for a long time.


The National Association of Home Builders recommends that you have your roof inspected by a qualified roofer every three years. The group says you can perform checks on your roof, too. At the start of each season, look for loose or damaged shingles, gaps in the flashing where the roofing and siding meet vents and flues; and damaged mortar around the chimney.


Even with the best care and maintenance, your roof can still sag. It’s best to educate yourself to know the causes of your sagging roof so that you will know what to do to fix it.

  1. The National Association of Home Builders recommends that you have your roof inspected by a qualified roofer every three years.

    1.Weakened roof material

    Water damage can be a major cause of roofing problems. It can cause sections of your roof to rot and weaken. There are lots of ways snow and rain can infiltrate your roof. Moisture can find weaknesses in your roof and settle there. As it sits, it causes the roofing material to deteriorate. It can even cause mold and mildew to develop, further weakening it. Your roof has some protection from the elements – shingles and flashing, or example – but that doesn’t mean that it’s impenetrable. Make sure your roof is properly draining rainwater off of it. Have a professional do periodic checks for signs of water damage. Poor ventilation is another way your roof material can weaken. Poor ventilation means that air isn’t circulating which means that moisture is sitting stagnant on your roof.

  2. 2.Faulty Roof Material

    The quality of your roofing material plays a big role in determining how long it will last. A roof constructed using asphalt shingles may be less expensive, but it won’t last as long as one that uses, say slate, which can sometimes last 100 years. This applies to all of the elements that come together to form the roof – beams, nails, etc. Also, the best roofing materials in the world won’t matter if they are not installed properly. Make sure that whatever roof work you have done is done by a professional.

  4. 3.Too Much Weight

    Snow, ice and rain can cause big problems if they’re allowed to settle and sit on your roof for a long time. Your roof is designed to support a certain amount of weight. It can withstand the occasional snow or rain storm, but prolonged stress isn’t good for it. According to information from the University of Arkansas, it’s important to weigh the risks when a homeowner is deciding whether or not to remove snow from a roof. "For example,” a report for the school reads, “if you leave the ice and snow on a roof, the roof may risk collapse. If you remove the snow, brittle shingles are likely to be damaged, or the person removing the snow may get injured. The expense and liability of having someone else remove the snow needs to be considered before taking action.” Try to learn how much weight your roof can take by getting the original plans for your house or by consulting a professional. A professional could also tell you whether the amount of snow or ice you are dealing with is safe or not.


    It’s so important to take good care of your roof. You can’t do this properly without teaming up with a professional you can trust. Find a good roof repair contractor with Pro Referral and do a little research on your own to make sure your roof lasts a long, long time.

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