Causes and Repairs For A Sagging Roof

Is a sagging roof dangerous? Yes, it is.

A sagging roof is dangerous and unsightly. When your roof starts sagging, you need to act fast. Learn about your options for a sagging roof in this guide.

What to Do With a Sagging Roof?

A sagging roof is always a cause for concern. Many may wonder, “Is a sagging roof dangerous?” While minor sags don’t necessarily mean your roof will collapse immediately, they can indicate that you need to repair or replace your roofing soon to prevent further damage. Keep reading to learn about your options for a sagging roof repair in this guide.

What Is a Sagging Roof?

A sagging roof is a warning sign of structural instability that could lead to collapse. Even a slightly sagging roof can cause leaks during severe weather, leading to mold, mildew, and other storm damage to your property. There is no degree of sagging that is acceptable for a roof.

Is a Sagging Roof Dangerous?

To answer the question, “Is a sagging roof dangerous?” Yes, a sagging roof is dangerous and can lead to leaks, which can cause damage to your home, so you must fix it immediately.

If left unchecked, this damage could eventually cause the entire structure to collapse, threatening not just the remainder of your house, but also the lives of you and your family.

What Does a Sagging Roof Look Like?

If you’re worried about the integrity of your roof, it’s essential to know what a sagging roof looks like. A sagging ridge line, or a slope in the middle of the roof, is an obvious sign of trouble.

You may also notice that some areas of your roof have become wavy or bowed, instead of flat or straight. Humps and pillowing are also potential signs that a roof is sagging. If you notice any of these problems in your home, it’s vital to have them assessed by a professional.

What Causes Roofs to Sag?

There are five leading causes of sagging roofs: excess weight, water damage, inferior materials or poor installation, age, and sinking foundations. Let’s explore each in more detail below.

Excess Weight

If a roof can only bear a certain amount of weight, anything more can cause the structure to sag. If your rafters are undersized or there isn’t enough support in place during storms,  or when snow and ice are resting on the roof, it may compromise its integrity.

Water Damage

If water damage has been an issue for your roof, it may start to sag as the wood rots underneath. You can fix this by replacing all affected wood with new lumber and ensuring there are no roof leaks or cracks in the waterproofing layers above it.

Inferior Bad Materials or Poor Installation

If there were problems with the materials used in the original construction of your home, or if someone didn’t know what they were doing when they installed your roof, it could start sagging after a few years of use. That is why it is important to call in a professional contractor to make sure everything is up to code. Here are a few ways to determine whether or not you need a new roof.


Most asphalt shingle roofs won’t last more than 30 years. Exposure to varying abrasive weather and fluctuating temperatures for years could lead to deterioration in its structural integrity, which can cause saggy spots.

Sinking Foundation

If your foundation has sunken over time due to shifting soil conditions or structural problems, your roof might be sagging. Your home’s frame could also start to bow, which would cause your roof to sink in at its center. A professional contractor can inspect your foundation for signs of damage and recommend a fix if necessary.

How to Determine if Your Roof Is Sagging?

You can determine whether or not a roof is sagging by inspecting it from all angles, starting outside and working your way up to the roof itself.

Outside Inspection

From the road, identify where the buckling or sagging is, so you can more closely inspect that particular area from the inside.

Wall Inspection

Examine the exterior walls to see if they are leaning or tilting. Check if the walls are plumb (or standing vertically) and window sills are level (sitting horizontally) by using a bubble level or plumb bob.

Attic Inspection

Moving around in the attic might be dangerous if you don’t watch your step. Take a flashlight and go up to your attic. Check for signs of wear on the roof such as splits, rot, or broken parts.

Inspection Safety

Always use proper safety equipment when climbing a roof, and be sure to have another person nearby in case of an emergency.

Climbing over HVAC ducts can be hazardous because of the potential for asbestos in the ducts or the insulation surrounding them. If you are working on an older property, check to ensure the ducts have asbestos-safe insulation materials already installed.

What Repairs can be Made to Fix a Sagging Roof?

Roofing professionals may typically fix sagging roofs without requiring a complete roof replacement. Repairs to fix sagging roof may include:

  • Reinforcing the current roof structure
  • Installing new supports or struts
  • Replacing insulation in the attic
  • Installing new sheathing and shingles

Some roofing problems are best dealt with by a professional. You should consider contacting a professional for a free estimate for a sagging roof repair today.

When Is it Time to Replace a Sagging Roof?

A sagging roof will become more severe and more costly to repair or replace. When you suspect your roof is sagging, it’s essential to determine whether or not the damage is beyond repair. Roofing specialists can investigate the sagging of a roof, evaluate its severity, and provide solutions to keep your house and family safe.

If you want to fix sagging roofs, they will be able to tell you whether it is better to have a new roof installed or have the old one repaired. Generally speaking, roof replacement is a better option if the roof is long past its life span or if there has been significant structural damage.

Bottom Line

Now that you know the answer to the question, “Is a sagging roof dangerous?” It is crucial that you take care of your roof and fix sagging roofs because it protects your home and your family from damage during storms or heavy rains.

By working with an experienced roofing contractor, you can repair and reinforce your roof with a sagging roof repair. Contact the professionals at Perfect Exteriors today to ask for a free estimate for a sagging roof repair.

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