Reuse fibreglass batts, rigid foam board, metal roofing panels and sound shingles only when they are dry and intact, and leave alone any insulation or roofing that might be asbestos, such as loose grey-brown pebbly attic fill, pipe wrap and cement-fibre shingles from before 1980. Metal roofing is the most valuable find, but its edges are razor sharp and sheets catch the wind, so label the panels, work with a partner and never walk on a damaged roof.
Part of Building Material Recovery
Insulation and roofing keep the weather out and the heat in, which makes them valuable, but they are exposed to water, age and fibres, and some contain materials best left alone.
Dryness And Age Decide What Is Safe To Reuse
Fibreglass batts. Reusable if dry. Wear gloves and a respirator, because the fibres irritate skin and lungs. Compressed fibreglass loses insulating value; fluff it back to its original thickness (parent article).
Rigid foam board (EPS, XPS, polyiso). Excellent insulation, reusable if not crumbled or water-damaged. Foil-faced polyiso loses some R-value when cold but works in walls and roofs (parent article). Foam burns and gives off harmful smoke, so keep it away from fires and stoves.
Cellulose insulation. Blown-in recycled paper. Not really recoverable in usable form once installed (parent article).
Metal roofing panels. Highly valuable salvage. Steel or aluminium panels are weatherproof, lightweight and easy to reinstall. Remove the screws, label which panels go together and transport carefully, because the edges are razor sharp (parent article).
Asphalt shingles. Reusable if not brittle. Old shingles become fragile and crack when handled. Partly worn shingles are better than no roof, and they are not worth long-distance transport (parent article).
Suspect asbestos. Asbestos was used extensively in buildings from before 1980 in pipe insulation, cement-fibre roof shingles and siding, and joint compound on ducts (parent article). Loose, pebbly grey-brown fill in older attics (vermiculite) can also contain asbestos. You cannot tell by looking: if the age and type fit, leave it undisturbed; see Asbestos, Lead Paint & Other Hazards.
What You Need
- Gloves, long sleeves, eye protection and a respirator.
- A pry bar, a drill or screwdriver and a hammer, for removing panels and shingles.
- A marker, to number panels in order.
- A ladder or scaffold in sound condition, and a partner.
- A dry storage area.
Method: Check, Remove, Label, Stack
Step 1: Check the roof from the ground first. Do not climb on a roof showing sag, rot or water pooling; see Signs of Imminent Collapse.
Step 2: Date and identify the material. If it fits the asbestos pattern, stop.
Step 3: Remove metal panels. Take out the screws rather than prying nails, working from the ridge down so you do not undercut yourself. Mark each panel with a number matching its place.
Step 4: Stack panels flat, edges protected, under cover, with weights if windy.
Step 5: Remove shingles gently with a flat bar, sliding it under each course. Discard any that crack.
Step 6: Insulation. Take batts out dry, shake them out in the open air and fluff them. Discard wet, mouldy or compressed-flat material.
Common Mistakes
- Reusing wet insulation. It no longer insulates and grows mould.
- Handling panels without gloves. Edges cut deeply.
- Working on a roof in wind. Sheets act as sails.
- Breaking old cement-fibre shingles. They may be asbestos.
- Transporting shingles long distances. They are heavy and easily broken (parent article).
Safety
Falls from roofs, razor edges and fibres
Falls from roofs are serious, so do not work on a damaged or wet roof, work with a partner, and keep three points of contact on a ladder. Metal panel edges cut like blades. Fibreglass irritates the lungs, and old fill or cement-fibre roofing may be asbestos, so do not break, sweep or burn it. Keep foam away from fire.
What’s Next
- Learn next: Asbestos, Lead Paint & Other Hazards — the check to run first
- Combine with: Vehicle & Machinery Cannibalization — the next salvage field