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Maintaining the integrity of commercial roofing is critical to protecting investments and operations. Choosing the best roof sealant plays a pivotal role in ensuring the roof’s functionality against the elements, which is why selecting the right one is vital. This guide focuses exclusively on the needs of commercial buildings, helping facility managers and commercial property owners make informed decisions about roof sealants.

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Why Roof Sealant is Important for Commercial Roofs

Roof sealants serve as a protective barrier for commercial buildings, shielding them from water intrusion, UV damage, and extreme weather conditions. This protection is crucial for prolonging the lifespan of a commercial roof, which, in turn, safeguards the building’s structure and its contents. Applying the best roof sealant enhances the building’s energy efficiency by providing thermal insulation and reflecting harmful UV rays, significantly reducing cooling costs. By preventing degradation and leaks, a high-quality roof sealant minimizes the need for frequent repairs, thereby saving on maintenance costs and extending the roof’s service life.

Types of Best Roof Sealants for Commercial Use

Commercial roofs have specific requirements due to their size, exposure, and the materials used, necessitating specialized sealants to meet these demands. Here are the most common types of sealants used in commercial roofing, each selected for its particular benefits:

Silicone Sealants

Ideal for commercial applications, silicone sealants are renowned for their durability and ability to withstand ponding water, making them perfect for flat or low-slope roofs prevalent in commercial buildings. They offer excellent weather resistance and long-lasting flexibility, making them a top choice for the best roof sealant in many commercial scenarios.

Polyurethane Sealants

These sealants are known for their strong adhesion and impact resistance, which are critical in areas that experience heavy foot traffic or mechanical stress. Polyurethane sealants are versatile and can be used on various substrates, making them another excellent option for commercial roofing needs.

Rubber Sealants (EPDM)

Rubber sealants provide exceptional waterproofing and flexibility, which are crucial for covering large surface areas typically seen in commercial settings. Their resilience makes them suitable for various weather conditions, solidifying their status as one of the best roof sealant choices for expansive roofing systems.

Acrylic Sealants

Acrylic sealants are a cost-effective option that provides good weather resistance and adhesion to diverse substrates. They are particularly valuable for commercial roofs requiring a reflective surface to help reduce cooling costs, though they may offer less durability than silicone or polyurethane.

Each type of sealant offers specific advantages that can be matched to the unique needs of a commercial roofing project. When choosing the best roof sealant, factors such as the local climate, roof design, and specific environmental challenges should guide your selection to ensure optimal protection and durability.

Factors to Consider When Choosing the Best Roof Sealant for Commercial Buildings

Selecting the best roof sealant for a commercial property involves considering multiple crucial factors to ensure that the chosen product meets the unique demands of your roofing system:

  • Durability: The sealant must withstand harsh environmental conditions and frequent exposure to UV light without degrading. Choosing a sealant that maintains its integrity and protective qualities over time is vital, making it one of the best roof sealant options for long-term durability.
  • Application Process: Commercial-scale applications may require specialized equipment and professional application to cover large areas efficiently. Consider the ease of application and whether the product can be quickly applied to minimize downtime and labor costs.
  • Compatibility: Ensure the sealant is compatible with the commercial roofing material, whether metal, modified bitumen, or a built-up roof (BUR). Using a sealant that bonds well with your specific roofing materials is key to avoiding leaks and extending the roof's lifespan.
  • Cost-Effectiveness: Factor in the sealant's upfront cost and expected lifespan to evaluate its overall value. The best roof sealant should balance initial expenses and the benefits of reduced maintenance costs and fewer reapplications over time.

Recommended Roof Sealants for Commercial Buildings

When it comes to commercial roofing, selecting the proper sealant is crucial for ensuring your building is protected against the elements. While it’s essential to assess all options and choose the best sealant for your specific needs, we are proud to offer a product that stands out for its exceptional performance in extreme conditions:

  • Terminator™ Roof Sealant: Part of our trusted product line, Terminator™ is a 100% solids moisture-cure sealant specifically formulated to handle the harshest weather conditions. Its siliconized-urethane formula is designed to quickly stop leaks and adhere to every roofing material, including typically challenging surfaces like silicone-coated roofs. Its ability to fully cure in wet and even underwater conditions sets Terminator apart, making it an ideal choice for areas prone to heavy rain or where roofs frequently contend with standing water.

While we confidently recommend Terminator™ for its robust performance and versatility, we encourage all facility managers and commercial property owners to consider the specific needs of their roofing projects. Factors such as the roof’s material, the typical weather conditions in the area, and specific performance requirements should guide your selection process. Our goal is to support you in finding the most suitable roofing solution that offers both protection and value, ensuring your commercial property remains secure and well-maintained.

How to Apply Roof Sealant on Commercial Roofs

Proper application of roof sealant is key to maximizing the lifespan and effectiveness of commercial roofing. This section will guide you through the essential steps, from preparing the surface and applying the best roof sealant evenly to allowing it to cure properly, ensuring your roof is well-protected and maintenance-free for years.

Surface Preparation

Cleaning the roof is the first and most critical step in the application process. Start by removing all debris, dirt, and any existing deteriorated coatings or sealants. Use a high-pressure washer if necessary to ensure the surface is impeccably clean. Rust and oxidation should be addressed for metal roofs, and any loose fasteners should be tightened or replaced. On membranes like EPDM or TPO, ensure that all seams are intact and repair any that are not. This preparation ensures the sealant adheres properly and performs as expected, preventing future failures and leaks.


Once the surface is prepared, the application of the sealant can begin. Using sprayers or rollers is the most efficient method for commercial roofs, which typically cover large areas. Ensure the sealant is applied uniformly across the roof surface to avoid pooling and uneven coverage. It’s important to apply the sealant at a consistent thickness as the manufacturer recommends. Areas around protrusions, such as vents, pipes, and HVAC units, require particular attention to ensure they are adequately sealed. Additionally, if applying in cooler temperatures, ensure the sealant is kept at an appropriate temperature, as some materials require this to flow and adhere correctly.

Curing Time

The final step in the application process is allowing the sealant to cure properly. Adhering to the manufacturer’s guidelines for drying or curing time is crucial for optimal performance. The curing time can vary based on the type of sealant used and the environmental conditions during application. For instance, humidity and temperature significantly affect how quickly a sealant dries. Avoid applying sealant if rain is expected soon or temperatures are outside the recommended range. During the curing period, keep traffic off the roof to prevent disturbances affecting the sealant’s integrity.

Maintenance and Reapplication for Commercial Best Roof Sealants

Maintaining the condition of commercial roofs is crucial to ensure they continue to provide optimal protection. Regular inspections are necessary to identify and address any signs of wear and tear or degradation in the sealant. Identifying issues early can prevent more significant problems and costly repairs in the future.

The timeline for reapplying the best roof sealant can vary depending on the specific product used and the conditions the roof is subjected to. Generally, commercial roof sealants should be reevaluated and potentially reapplied every 5 to 10 years. However, high-traffic areas, roofs under severe environmental conditions, or those with previous leakage issues may require more frequent attention.

To ensure that the sealant continues to perform effectively, it’s essential to follow the manufacturer’s guidelines for reapplication. Staying proactive with maintenance and timely reapplications will extend the roof’s life and maintain its integrity, ensuring it remains a reliable barrier against the elements.

Best Roof Sealant: Frequently Asked Questions

Silicone sealants are often recommended for flat commercial roofs due to their excellent resistance to ponding water and UV light.

It depends on the type of sealant and the roof’s exposure to elements, but generally, commercial roof sealants should be inspected and potentially reapplied every 5 to 10 years.

Yes, using approved sealants as part of regular maintenance can extend a roof’s warranty. Always check with the sealant manufacturer and the roofing material provider to ensure compatibility and warranty compliance.


Proper sealant is crucial for maintaining commercial roofs’ structural integrity and longevity. Understanding the different types of sealants and their specific benefits ensures your commercial property is well-protected against various environmental challenges. Choosing the best roof sealant not only enhances the durability and resilience of your roof but also contributes to overall building safety and operational efficiency. It’s an investment in safeguarding your assets against future repairs and potential damage, providing peace of mind that your commercial space is secure under all weather conditions.

If you need your commercial roof repaired, schedule a free roof inspection with an American WeatherStar-approved Contractor today.