Sagging Roof? Causes & Solutions

What Are Some Signs of Roof Sagging? 

In many cases, a sagging roof will be fairly obvious just by observing the roof from the outside. If you aren't sure, there are a few places you can look to be more confident that you have a problem. 

Look for a Bow in the Roofline 

The roofline is the edge of the roof where your gutters, soffit, and fascia are located. Look for any dip in the roofline, especially towards the middle. You can hold out a ruler in front of you horizontally to line it up with the roof if that helps. Sometimes, bowing here can indicate a localized problem if it's just damage to the edge or overhang (if you have one). More often, it indicates the result of serious damage at the structural level.  

Look for Sagging at the Ridgeline 

The next place you can look for sagging is the ridgeline, which is the top ridge of your roof. You may see a dip toward the middle from the force of the roof pushing outward against the sides over time. 

Look for Curving or Waviness 

If just a portion of the roof is damaged, you may notice bubbling or waving in a single area of the roof. This could indicate some rafters are not secured properly or that some beams have become damaged. It could also indicate that the roof decking is rotting from a leak. 

Look for Any Dipping Where the Roof Should Be Flat 

Sometimes roof damage is structural and sometimes it is local. If you notice that the ridgeline or rooflines look okay, but you still notice a part of the roof dipping, then you will still need to have a roofer fix damage where the dip is occurring. Failing to address isolated roof damage will most likely cause widespread damage over time. 

Other Signs 

There are several other signs not-related to the roof that you can look out for as well. We've dropped a few of them below. 

• Water Damage: If you know water damage has occurred in your attic or around your roof, this is a common cause of structural damage. 
• Cracks In Outdoor Masonry or Indoor Walls: Anytime cracks are showing up around the home, there's a good chance there is damage occurring to the foundation and/or the roof. 
• Doors/Windows Won't Shut: This could mean you have a lot of snow on your roof, or that your roof is sagging more than it should be. 

What Causes Roof Sagging? 

We move on now to survey some of the common causes of serious structural roof damage. Sometimes, it is a simple as old age or as complex as poor construction. 

Storm Damage & Deterioration from Moisture

Snowfall, wind, rain, and hail are all threats to the integrity of a roof. A single severe storm can damage shingles enough to allow moisture entry. Once a single leak has occurred, it can quickly lead to mold growth and wood rot. Wood deterioration from moisture will eventually result in your roof no longer being able to support its own weight. 

Snow & Ice Buildup (Weight Damage)  

Any kind of excess weight on the roof can damage the support structures. Most people do not realize that snow and ice can exert a tremendous amount of weight downward onto a roof. This can damage a roof in a single season, but it is more likely to cause damage over time from the seasonal cycle. When this damage occurs, it probably means the initial roof design didn't include enough trusswork or the rafters/trusses are undersized.  

Foundation ISsues 

We mentioned earlier that sometimes foundation problems and roof problems go hand-in-hand. If your home is built on red clay or you are aware of soil settling under your home, foundation shifting may be part of the reason your roof has misaligned. 

Internal Bracing Problems 

With poor construction, braces may carry too much weight will eventually begin to collapse. Braces need to share the weight of the roof with an interior wall in order to provide sufficient support. 

Problems with Trusses or Rafters

Some homeowners will remove some trusses to create more attic space. Because equal distribution of weight is important to the long-term stability of the roof, this is almost never a good idea. 

Improper handling of beams during installation can also lead to eventual failure. Beams have to be aligned extremely carefully; otherwise, weight will be improperly distributed and this will lead to buckling. 

Occasionally, a disreputable or negligent roofer will use low-quality timber or defective wood with knots. People who have been in the roof repair industry long enough have seen this all too often. 

Termites 

Termites are usually only present if there's already other problems like moisture. They are attracted to moldy and rotting wood, which is something that should be addressed anyway. Take care of the moisture problem and the odds of a pest infestation are reduced significantly. 

Can a Sagging Roof Collapse?  

The answer is yes. Anytime a roof has reached a point where it is visibly drooping or buckling, structural integrity has been compromised and will continue to worsen. The good news is that most people will recognize the signs clearly and get professional repairs before a collapse takes place.

How to Fix a Sagging Roof

First, inspect the beams in the attic to determine how much of the damage is taking place under the decking. Look for cracks, rotting, or disconnects where rafters and trusses should be fastened.

Second, if there are no obvious issues with the beams, inspect the roof decking. Check to see if this is primarily where damage is occurring. Remove the shingles where the roof is curving to evaluate the state of the decking. 

If there is roof rot, this may be the main problem. Replace any rotted decking as needed. 

If the issue is under the decking, replace any damaged beams. This work should be completed by a professional because any misalignment with major structural support will cause improper weight distribution. Over time, this will lead to more roof sagging as beams buckle under too much weight. 

Get in Touch with Honest Abe Roofing for Support 

Give our team a call today if you have any questions about your sagging roof. Our team will come out and perform a free inspection so you can understand the nature of the problem. Reach out by phone or check out our locations page for a team that's in your area. 

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