Can You Put Roof Coating on Shingles

Can You Apply Roof Coating on Shingles?

Applying roof coating on shingle roofs is a question many homeowners and contractors ask when looking to extend the life of their roofing system. The good news is that roof coatings can be applied over asphalt shingles, but certain conditions and preparation steps must be met to ensure proper adhesion, durability, and protection. This article explores the best practices, types of coatings suitable for shingle roofs, and important factors to consider before coating your shingled roof.

How Roof Coatings Work on Shingle Roofs

Roof coatings provide a protective layer over the existing roofing material. When applied to shingles, the coating acts as a waterproof barrier, reflects sunlight to reduce heat, and helps prevent damage caused by UV rays and weathering. This protection can extend the lifespan of shingles by slowing the natural deterioration process caused by exposure to elements.

However, the performance of a roof coating is highly dependent on the condition of the shingles. Applying coating over damaged, curling, or missing shingles will not resolve the underlying issues and can lead to rapid coating failure. Therefore, inspecting and repairing the shingle roof before coating is critical.

Types of Roof Coatings Suitable for Shingles

Acrylic Roof Coatings

Acrylic coatings are water-based and popular for shingled roofs due to their breathability and UV resistance. They help reflect sunlight, reducing roof temperatures which can improve energy efficiency inside the home. Acrylic coatings adhere well to clean, dry shingles and are cost-effective.

Silicone Roof Coatings

Silicone coatings offer excellent waterproofing and resist ponding water better than acrylics. They are highly durable and maintain flexibility over time. Silicone coatings are suitable for areas with heavy rains and where water pooling on the roof is a concern.

Elastomeric Roof Coatings

Elastomeric coatings are highly elastic and can handle the expansion and contraction of roof materials. These coatings seal small cracks and provide strong resistance to weather elements, making them ideal for roofs that experience temperature fluctuations.

Asphalt-based Coatings

Asphalt-based coatings are traditionally used on asphalt shingle roofs and can help rejuvenate old shingles. These coatings provide waterproofing but require careful application to prevent trapping moisture beneath the roof surface, which can cause shingle damage.

Steps to Apply Roof Coating on Shingles

1. Inspect and Repair: Check for damaged or curling shingles, and replace or repair before coating.
2. Clean the Roof Surface: Remove dirt, moss, algae, and debris using a roof cleaner or power washer (make sure the roof thoroughly dries after cleaning).
3. Check Weather Conditions: Apply coating during dry, moderate weather to ensure proper curing and adhesion.
4. Apply Primer (If Needed): Some coatings require a primer layer for better adhesion on shingles.
5. Apply Roof Coating: Use a brush, roller, or sprayer depending on the product and roof size; apply the recommended number of coats.
6. Allow for Proper Drying Time: Follow the manufacturer’s guidelines on curing times before exposing the roof to heavy rain or foot traffic.

Important Considerations Before Coating Shingle Roofs

• Roof Age and Condition: Coating is more effective on roofs less than 10 years old or in good condition.
• Ventilation: Good attic ventilation is essential to prevent moisture buildup under the shingles or coating.
• Compatibility: Ensure the coating product is compatible with asphalt shingles to avoid adhesion and durability problems.
• Manufacturer Specifications: Follow product guidelines carefully for application thickness, temperature, and maintenance.
• Limitations: Roof coatings do not fix structural damage or replace the need for shingle replacement if the roof is severely worn.

Benefits of Applying Roof Coating on Shingles

Applying roof coatings on shingles extends the roof’s lifespan by up to 10 years by adding a protective barrier against UV rays, weather, and moisture. Coatings also improve energy efficiency by reflecting sunlight, lowering roof temperature, which reduces cooling costs.

Additionally, roof coatings can help reduce maintenance costs by sealing minor leaks and cracks, preventing expensive repairs. Environmentally, roof coatings delay the need for roof replacement and lessen landfill waste from old shingles.

Common Myths About Coating Shingle Roofs

• Myth: Roof coatings make shingles waterproof forever.
  Fact: Coatings improve waterproofing but may require re-application every 5–10 years based on product and climate.
• Myth: You can coat any shingle roof regardless of its condition.
  Fact: Coatings should only be applied on sound shingles; damaged roofs need repairs first.
• Myth: Coatings trap moisture under shingles.
  Fact: Proper surface preparation and breathable coatings prevent moisture buildup.

When Not to Use Roof Coating on Shingles

Roof coatings are not a suitable solution if the shingle roof shows significant wear including missing or broken shingles, excessive curling, granule loss, or structural damage. Coating over these problems is a temporary fix at best and can lead to concealed damage and accelerated roof failure.

If the roof is older than 20 years, replacement may be a more cost-effective and safer approach instead of coating.

Professional vs. DIY Application

While roof coatings can be applied by experienced DIYers, professional application ensures proper surface preparation, correct product choice, and uniform coating thickness. Professionals also identify hidden roof issues that might interfere with the coating’s performance.

For large or complex roofs, or if safety is a concern, hiring licensed roofing contractors is recommended. Proper application affects not only the performance but also the warranty coverage of the coating product.