Built-up roofing (BUR) systems have been a staple for flat and low-slope roofs across commercial, industrial, and institutional buildings for decades. Known for their multi-ply redundancy and durability, BUR systems still face common aging issues like UV degradation, ponding water, and thermal cycling stress. The right roofing coatings not only extend the service life of built-up roofs but also deliver energy savings and reduced maintenance costs.
For distributors and procurement specialists serving roofing contractors, understanding which coatings deliver the best performance for BUR restoration is vital.
Why Coatings Matter for BUR Systems
Over time, built-up roofs experience:
Cracking and Alligatoring: From UV breakdown of the asphalt layers.
Ponding Water Damage: Leading to accelerated degradation in low spots.
Thermal Expansion Stress: Causing seams and flashings to deteriorate.
Loss of Reflectivity: Resulting in higher roof temperatures and energy costs.
Applying a high-performance roof coating acts as a seamless membrane that rejuvenates aged surfaces, blocks UV rays, and improves water resistance.
Types of Roof Coatings for Built-Up Systems
Acrylic Coatings
Water-based and highly reflective.
Ideal for dry climates with minimal ponding.
Cost-effective and easy to apply.
Examples: Henry 587 Dura-Brite or GAF Roof Mate.
Silicone Coatings
Superior ponding water resistance.
Highly UV stable and durable.
Performs well in humid or rainy climates.
Examples: GE Enduris or Mule-Hide Silicone Roof Coating.
Polyurethane Coatings
Two-component systems offering abrasion resistance.
Great for roofs subject to mechanical wear (foot traffic, HVAC equipment).
Available in aromatic (cost-effective but UV-sensitive) or aliphatic (UV-resistant) formulations.
Asphalt Emulsion Coatings
Traditional option for BUR systems.
Reinforces asphalt-based roofs with added waterproofing.
Often used as a base layer with reflective topcoats.
Key Performance Considerations
UV Reflectivity: High Solar Reflective Index (SRI) reduces heat load, lowers cooling costs, and mitigates thermal cycling.
Ponding Water Resistance: Silicone coatings are the industry leader here, far outperforming acrylics in standing water conditions.
Adhesion to Asphalt: Not all coatings bond equally to aged BUR. Proper cleaning, priming, and choosing compatible products are critical.
Elasticity and Tensile Strength: Look for coatings with high elongation (>200%) to handle building movement without cracking.
Warranty Lengths: Top-tier manufacturers offer 10-20 year warranties depending on mil thickness and system type.
Application Best Practices
Surface Preparation: Clean the roof thoroughly. Remove dirt, loose gravel, algae, and degraded material. Power washing is often required.
Priming: Apply asphalt-compatible primers when recommended to enhance coating adhesion, especially for silicone and polyurethane systems.
Reinforced Systems: For heavily deteriorated roofs, embed polyester fabric into the base coat to bridge cracks and seams.
Correct Thickness: Follow manufacturer guidelines. Too thin a coat reduces lifespan; too thick may cause curing issues.
Weather Windows: Acrylics require dry conditions for curing, while silicones can tolerate more moisture during installation.
When Coatings Make Sense Over Replacement
Cost Efficiency: Roof restoration typically costs 5070% less than full tear-offs.
Disruption Avoidance: No need to shut down operations during coating applicationscritical for hospitals, schools, and manufacturing facilities.
Sustainability: Extending roof life reduces landfill waste from old roofing materials.
Conclusion
Roof coatings are more than a stop-gaptheyre a proven strategy to add 10 to 20 years of service life to built-up roofs. Whether selecting silicone for ponding resilience, polyurethane for foot-traffic durability, or acrylic for cost-effective reflectivity, distributors play a crucial role in guiding contractors to the right solution.
Helping your customers understand coating compatibility with BUR systems, application methods, and performance expectations ensures not only project success but long-term customer satisfaction. In a market where roofing budgets are tight and sustainability is in focus, coatings are a win-win for property owners and roofing professionals alike.
