The material in question

For decades, rigid siding panels and roofing shingles were made by mixing cement with fibers, and asbestos was one of the fibers used. On mid-century homes around the metro you may see it as wide, flat panels with a faint texture or pattern, sometimes painted, often with a characteristic wavy or straight lower edge. Some garages and outbuildings have corrugated sheets of similar material.

When intact, this kind of product is generally considered non-friable. Hail changes that. Stones crack and puncture panels, leaving broken edges and fragments in the grass and gravel. The bigger concern is the replacement: prying, breaking, cutting or power-washing older cement products can release fibers.

Routine siding replacement versus suspect cement siding

Typical replacement of non-suspect siding

  • Panels are pried off and tossed in a dumpster
  • Cutting new pieces happens on site with power saws
  • Debris goes to ordinary construction waste
  • Work can start as soon as materials arrive

Older cement siding that may contain asbestos

  • Sampled by a certified inspector before removal
  • If positive, removed whole where possible, kept wet, not broken
  • Packaged and hauled to a facility permitted for asbestos waste
  • Removal by certified personnel, with any required CDPHE paperwork

After a hailstorm, if your siding or roof may be cement-based

  • Photograph damage from the ground; do not climb up to pick at cracked pieces.
  • Do not pressure-wash broken panels to clean them up.
  • Leave fragments in the yard where they lie rather than sweeping or mowing over them, and keep children away.
  • Tell your insurer the siding or roofing may be an older cement product that needs testing.
  • Ask each contractor bidding the replacement whether they have accounted for testing and certified removal.
  • Get the inspector's report before signing a replacement contract.

Questions for a roofing or siding contractor

  1. Do you recognize this as a possible asbestos-cement product?
  2. Who will sample it, and who will remove it if it is positive?
  3. What CDPHE certification does the removal contractor hold?
  4. How will broken pieces from the hail be collected?
  5. Where will removed material be disposed of, and will I receive the paperwork?

General information for the Denver area, not a quote or professional advice. In an emergency, call 911.