Sunlight’s Effect On The Roof – Plus Preventive Measures

April 26, 2021

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The weather has a significant effect on your roof’s integrity and durability. Different weather elements, such as rainfall, snow, wind, and sunlight, have different effects. Many people don’t understand the sun’s effect on the roof since it’s gradual, but the prolonged effects of sunlight do cause damage to this part of your home. Learn about some of the damage that may occur and how it can be prevented.

Types of Sun Damage

Sunlight damages the roof in various ways.

Expanding and Contracting Roofing Materials

Most things, roofing materials included, expand when heated and contract upon cooling. Roofing materials will expand during the day when the sun is too hot. The materials will then cool and contract when the sun goes down. Unfortunately, the constant contraction and expansion weakens the materials and increases their wear and tear.

Dry Shingles

Some roofing materials, such as asphalt shingles, have oils that make them flexible. The flexibility means the materials don’t crack easily under strenuous circumstances, for example, due to thermal shock. Unfortunately, ultraviolet (UV) rays from the sun dry out the asphalt shingles and increase their brittleness. The dry shingles can easily crack, curl, or warp.

Roof Discoloration

UV rays from the sun can also discolor your roof. The discoloration process depends on your roofing materials. For example, some materials naturally degrade and lose their color with time, but the UV rays accelerate discoloration reactions. Asphalt shingles also lose their color when they dry, become brittle, and lose their granules.

Preventive Measures

You might not completely avoid the effects of sunlight on your roof, but you can mitigate them. Below are some measures that can help.

Install a Cool Roof

A cool roof reflects most of the sunlight that falls on it, absorbing only a small fraction of it. You can make your roof cool by:

• Using reflective roofing materials, such as reflective shingles
• Painting the roof white or another light-colored shade
• Covering the roof with a reflective sheet
• Applying a reflective coating over the roof 

The local climate, your budget, and roofing materials are some of the factors that will determine the best technique to use.

Choose the Right Material

Sunlight and heat affect some roofing materials more than others. Therefore, choose materials that won’t easily damage if you are concerned about heat damage. A good example is rubber (EPDM) roofing, which doesn’t crack or break despite UV radiation. Light-colored EPDM is even better since it will also reflect most of the sunlight.

Install a Green Roof

A green roof includes a layer of vegetation or plants on the roof. The vegetation provides an insulation cover over the roof, blocking most of the sunlight from reaching the roof’s surface. Green roofs are best for flat roofs so that the plant’s watering doesn’t lead to water running down the roof. Green roofs are only suitable for some roof configurations, so your existing roof might need modification.

Apply UV-resistant Sealant

Many people use roof sealants to waterproof their roofs and reduce wear and tear. However, some sealants are also UV-resistant. For example, acrylic or silicone sealants offer more UV resistance than polyurethane sealants.

Ensure Adequate Ventilation and Insulation

Roof heat damage doesn’t confine itself to the roofing material’s outer surface. Some of the heat can penetrate through the roof, heat up the attic, and cause further damage. Insulate the attic to minimize the amount of heat that can get into the house. You also need to ventilate the attic so that it doesn’t trap heat but releases it into the atmosphere.

Some of these measures are suitable for new roofs, while others can work on existing roofs. Barrier Roofs can help you mitigate sun damage whether you have an existing roof or need a new installation. Contact us for a quote or consultation and benefit from our roofing expertise and experience.