Modified bitumen is an asphalt-based membrane family used in low-slope roof assemblies. Performance depends on the selected system, sound substrate, drainage, and correctly executed seams and flashings.

What to check first

  • Distinguish a local surface defect from trapped moisture or assembly failure.
  • Check parapets, equipment curbs, and drain connections.
  • Leave torch-applied installation and fire-sensitive details to trained professionals.

Evaluate the complete roof assembly

  1. Inspect what is beneath the surface

    Wet insulation, damaged decking, unsuitable attachment, and trapped moisture can change the scope of work. A new top layer cannot restore deteriorated supporting components.

  2. Plan the transitions and drainage

    Coordinate edges, parapets, penetrations, drains, and overflow routes with the selected system. These connections are part of the roof, not finishing details to improvise later.

  3. Use a building-specific specification

    Follow the selected manufacturer’s assembly requirements and appropriate professional review. Torch application, structural changes, and concealed damage need qualified personnel rather than a general DIY recipe.

Watch the field examples

These archive demonstrations show individual projects. Use the current guidance above and Bergstrom’s published instructions if an older video shows a different product or method. Torch work shown in installation videos is professional work.

From the project archive

Torch Down Roofing for Commercial Rubber Roofs - 2 rubber membranes with a fiber base.
Historical project photo · Flat Roof Doctor
Torch Down Roofing - This shows the thickness of a two ply system Modified Bitumen
Historical project photo · Flat Roof Doctor
Torching down roofing or heat fusing a Modified Bitumen Rubber Membrane
Historical project photo · Flat Roof Doctor

Product reference: Bergstrom Industries’ published knowledge catalog. Follow the latest product label and safety information. Historical project examples are educational and are not a specification for every roof.