Stone-Coated Steel Roofing

Stone-coated steel products are steel sheets, usually with a zinc or aluminium-zinc metallic coating, that are press-formed into multi-tile panels or shingle shapes and then coated with an acrylic base, natural stone granules and a clear overglaze. The granules give a textured, matte surface that imitates clay or concrete tile, wood shake or asphalt shingles, while the steel provides strength and light weight.

Profiles

Manufacturers offer profiles that copy Mediterranean barrel tile, scalloped tile, flat shingle and split shake. Panels are typically fixed to battens or directly to the deck and lock together at their edges.

Performance claims

Product literature commonly reports:

• Impact: UL 2218 Class 4, the highest class in that test.
• Fire: Class A fire ratings for complete assemblies.
• Wind: testing to wind-driven rain and high-velocity hurricane zone protocols, with wind warranties stated in miles per hour by individual manufacturers.

As with any proprietary product, these ratings apply to the tested assembly and should be checked against the specific product listing.

Characteristics

• Light compared with clay or concrete tile, so it can suit older structures and re-roofing.
• The textured, three-dimensional surface helps disguise minor dents.
• Cut edges and scratches expose the metallic coating and need appropriate touch-up as directed by the manufacturer.

Regional use

Stone-coated steel is generally traced to New Zealand and is used in many regions, particularly where heavy tile is impractical or where hail and hurricanes are concerns.

Installation notes

Because the panels are steel, their life depends on the metallic coating and the protection given by the stone layer. Profiles imitating tile and shake allow owners to keep the appearance of traditional roofs while reducing weight.