Torch-on roofing (also known as torch-down roofing) is a popular method for flat or low-slope roofs, commonly used in commercial and residential buildings. It involves applying layers of modified bitumen (asphalt combined with rubber or plastic) to the roof’s surface using a propane torch. This heat-fused process creates a durable, waterproof seal that can withstand various weather conditions.
Key features of torch-on roofing:
- Durability: Torch-on roofs typically last 15-20 years or more with proper maintenance, providing excellent resistance to UV rays, punctures, and general wear and tear.
- Waterproofing: The heat-welded seams create a strong, seamless, and impermeable layer, reducing the risk of leaks.
- Flexibility: Modified bitumen allows the material to expand and contract with temperature changes without cracking.
- Multiple Layers: Torch-on roofing is often applied in two layers—a base sheet and a cap sheet—offering added strength and longevity.
- Low Maintenance: These roofs require little upkeep, though periodic inspections for damage or wear are recommended.
Installation Process:
- Preparation: The roof deck is first cleaned and primed.
- Base Layer Application: A base sheet is rolled out and adhered to the deck with adhesives or mechanically fastened.
- Torching the Cap Sheet: The top layer (cap sheet) is rolled out, and a propane torch is used to melt the bitumen as the sheet is unrolled, fusing it to the base layer.
Torch-on roofing provides strong protection against elements, making it ideal for flat roofs that need to handle ponding water. However, because it involves open flames during installation, it’s essential to hire experienced professionals to ensure safety and quality workmanship.