Why Is My Roof Sagging?

Damaged tile roofHave you noticed a bit of a sag in your roof? You may be in danger because a sagging roof isn’t just unattractive—it might be a sign your roof could eventually collapse. We’ll detail the 2 main causes of a sagging roof and what your next steps should be from here.

Roof Material Has Weakened

Imagine soaking some bread in water; it gets all mushy and easy to break, right?

Same thing happens when water finds its way into your roof and settles there: it causes materials to rot and weaken.

A few ways water can find it’s way into your roof includes:

  • Missing tiles or shingles
  • Deteriorated underlayment (material under the roofing to protect against water_
  • Damaged roof flashing (material used over joints in roof construction to prevent water seeping in)

A poorly ventilated attic can also cause a roof to weaken. Improper attic venting can lead to moisture buildup, which can cause mold growth and wood rot, leading the roof to sag. The key to proper attic ventilation is to create continuous air circulation throughout the attic space (like with an attic fan) while preventing moisture from entering. In an ideal venting system, air should enter the attic from the eaves or soffits and escape outside at the roof ridge. Click here to learn more about attic ventilation.

Too Much Weight/Not Enough Support

Another reason your roof may be sagging is because it can’t handle the weight of the roofing material. For example, tile roofing weighs WAY more than your typical asphalt shingle roofing. If your home has converted from shingles to tile, you may need to add structural bracing in your attic to hold the extra weight.

It’s also possible that some inexperienced roofer added another layer of shingles when they shouldn’t have. To save money, some homeowners will have a layer of shingles added over their current shingles so that the roofer does not have to tear them off. However, most building codes prohibit adding a third layer of shingles. The reason is simple: a third layer adds too much weight to the roof.

Related: Can I Install a New Shingle Roof Over My Existing Roof?

Your Next Steps

You don’t want to have your roof repaired if there are any problems with the structure of your home. Roofs are HEAVY, so your home needs to be strong enough to support it. First, you need to know if your home is structurally sound. A professional roofer would be happy to coordinate with a structural engineer to analyze and correct any structural issues.

Lyons Roofing works closely with West Point Engineering; you can email Farley Rhoads at frhoads@cox.net. Once any structural issues have been corrected, then you’ll need to contact a professional roofer to do roof work.