How to Spot Signs of Structural Damage to Your Roof: Sagging, Warping, and Discoloured Areas


Your roof serves as the first line of defence for your home against the elements. It is crucial to keep your roof in good condition to protect your investment and ensure the safety of your family. One of the most pressing concerns is structural damage, which can lead to significant problems if left unaddressed. In this article, we will explore how to spot signs of structural damage to your roof, focusing on three common indicators: sagging, warping, and discoloured areas.

  1. Sagging Roof

A sagging roof is a clear sign of structural issues, and it is important to address it promptly. The causes of a sagging roof can vary, but the primary culprits are typically inadequate support or excessive weight.

a. Inspect from the Inside: One way to check for sagging is to go into your attic and look for visible signs from the interior. Use a flashlight to examine the structure of the roof, especially the rafters and trusses. Look for any areas where the wood appears to be bending, sagging, or showing signs of stress. If you notice any of these issues, it is an indication of a structural problem.

b. View from the Exterior: From the outside, stand at a distance and examine your roofline. A sagging roof will appear uneven or warped. You may also notice a noticeable dip or droop in the roofline. This is often a tell-tale sign that something is amiss with the structural integrity of the roof.

c. Cracked or Sagging Drywall: Inside your home, check for cracks in the ceiling or walls. These cracks may indicate that the roof structure is sagging, causing stress on the interior drywall. Pay close attention to areas where the walls meet the ceiling, as these are often the first places where cracks become visible.

  1. Warping Roof

Roof warping is another clear sign of structural damage. Warping can occur in several forms, including cupping, curling, and buckling of the roof material.

a. Curling Shingles: Examine your roof from the ground or atop a ladder. Curling or buckling shingles are a sign of structural problems. This typically happens when the roof deck becomes moist or begins to deteriorate.

b. Cupped or Warped Shingles: Roof shingles should lay flat and even. When they start to cup or warp, it is usually a sign that the underlying structure is compromised. Cupped shingles tend to create a concave shape, while warped shingles may exhibit a more pronounced curve.

c. Check for Uneven Lines: Warping can also affect the lines of your roof. Walk around your property and observe the roof’s lines and ridges. An uneven, wavy appearance is often an indication that the roof structure has weakened.

  1. Discoloured Areas

Discoloured areas on your roof may not always be a result of structural damage, but they can be an early warning sign of problems that can lead to structural issues. Stains and discoloration can be caused by several factors, including water damage, mould, and algae growth.

a. Dark Stains: Dark stains or discoloration on your roof are often a sign of water damage. These stains can indicate that water has penetrated the roof’s surface and is causing damage to the underlying structure. Water damage can weaken the roof’s structural integrity over time.

b. Mould and Algae: Mould and algae growth can affect the appearance of your roof and, if left unaddressed, can lead to structural issues. Mould and algae can thrive in damp, shaded areas of your roof and deteriorate the roof material, which can ultimately weaken the roof’s structural integrity.

c. Moisture Damage: Discoloration and staining can also be a result of moisture damage, which can weaken the roof structure over time. If you notice that your roof is regularly wet, or if it does not dry out quickly after rain, this could be a sign of moisture-related issues.

What to Do When You Spot Signs of Structural Damage

  1. Safety First: If you suspect structural damage to your roof, it’s crucial to prioritize safety. Do not climb onto your roof to inspect the damage, as it could be unstable. Instead, hire a professional roofer who is experienced in handling structural issues.
  2. Consult a Professional: When you spot any of the signs mentioned above, it’s best to call a licensed roofing contractor for a thorough inspection. They can assess the extent of the damage, identify the root causes, and recommend the necessary repairs.
  3. Timely Repairs: Promptly address structural issues to prevent further damage. Ignoring the problem can lead to more extensive and costly repairs down the line, as well as potential safety hazards.
  4. Documentation: When you notice structural damage, take photos or make notes to document the issue. This documentation can be useful when working with your insurance company or contractors.
  5. Insurance Claim: If the structural damage is a result of a covered peril (e.g., storm damage), contact your homeowner’s insurance company to assess your coverage and file a claim if applicable.
  6. Regular Maintenance: To prevent future structural issues, invest in regular roof maintenance and inspections. A proactive approach can identify potential problems before they become major structural concerns.


Your roof is a critical component of your home’s structure, and it’s essential to keep it in good condition to protect your investment and maintain the safety of your household. Signs of structural damage, such as sagging, warping, and discoloured areas, should never be ignored. Early detection and timely repairs can help prevent further damage, save you money, and ensure the long-term structural integrity of your roof. If you suspect any structural problems with your roof, don’t hesitate to contact a professional roofing contractor to assess the situation and recommend the necessary repairs.