Avelar Home Inspection Inc.

Common Roof Defects in a Home


The roof is one of the most prominent features of a home, as it protects it from the elements and provides structural support. However, roofs are also prone to various defects that can compromise their performance and durability. Some of these defects are caused by poor installation or workmanship, while others are due to weathering, wind, improper maintenance, or design flaws. Here are some of the most common roof defects that you should be aware of and how to prevent them.

## Poor Workmanship

Many roof problems stem from poor installation or workmanship, such as improper fastening, flashing, or sealing. These mistakes may not be apparent right away, but they can lead to leaks, blistering, shrinkage, or premature failure of the roofing material over time. To prevent this defect, you should always hire a reputable and licensed roofer who follows the manufacturer’s instructions and industry standards when installing your roof.

## Blistering

Blistering is a condition where bubbles form on the surface of asphalt shingles due to trapped moisture or air. This can be caused by shingle breakdown, poor ventilation, excessive heat exposure, or improper application. Blistering can reduce the lifespan and aesthetic appeal of your roof by making it more susceptible to cracking and tearing. To prevent this defect, you should ensure adequate ventilation in your attic space and avoid applying shingles on wet surfaces or under high temperatures.

## Leaks

Leaks are one of the most obvious and damaging roof defects that can affect any type of roofing material. Leaks can be caused by various factors such as missing or damaged shingles, improperly installed flashings, clogged gutters and downspouts, ice dams, or structural issues such as sagging or spreading. Leaks can result in water damage to your ceiling, insulation, walls, floors, furniture, and belongings. They can also create mold growth and health hazards in your home. To prevent this defect,

you should inspect your roof regularly for signs of wear and tear and repair any issues promptly. You should also clean your gutters and downspouts regularly and install proper insulation and ventilation to prevent ice dams.

## Shrinkage

Shrinkage is a condition where roofing materials contract due to changes in temperature or humidity. This can affect single-ply membranes such as EPDM (ethylene propylene diene monomer) or TPO (thermoplastic polyolefin), as well as built-up roofs (BUR) with organic felts. Shrinkage can cause cracks, wrinkles, or tears in the roofing material, as well as pull away flashings from walls or chimneys. This can expose your roof to water infiltration and deterioration. To prevent this defect, you should choose roofing materials that are compatible with your climate and have adequate flexibility and elasticity.

You should also ensure proper installation and fastening of the roofing material and flashings.

## Improper Design

Some roof defects are due to improper design rather than poor workmanship or weathering. For example, a roof may have an inadequate slope, drainage, or support system that causes water accumulation, sagging, or spreading. Another example is using incompatible roofing materials that react negatively with each other or with other building components.

These design flaws can compromise the functionality and longevity of your roof by creating stress points, leaks, or corrosion. To prevent this defect, you should consult a professional roofer or architect before designing or remodeling your roof. You should also follow building codes and regulations regarding roof design.



Roofs are exposed to various factors that can cause defects over time. Some of these defects are minor and easy to fix, while others are major and require extensive repairs or replacement. By being aware of these common roof defects and how to prevent them, you can protect your home from potential damage and save money on future maintenance costs. However, if you notice any signs of roof problems in your home, you should contact a qualified roofer immediately for an inspection and diagnosis.

AVELAR HOME INSPECTION info@avelarhomeinspection.com 613-797-8184