Metal Roof Tiles (Press-Formed Tile Sheets)

Metal roof tiles, also called pressed metal tiles or tile-effect sheets, are made by pressing metallic-coated steel or aluminium in a die so that one panel carries several rows and columns of tile shapes. Each panel replaces many individual clay or concrete tiles. Finishes are either factory paint, often with a matte or textured coating, or a stone-granule coating.

Typical products

• Painted press-formed tile sheets: often sold in long sheets with stepped tile courses.
• Stone-coated tile panels: steel with an acrylic base, stone granules and glaze, imitating barrel or scalloped tile.
• Individual pressed metal tiles: smaller units, sometimes with locking edges, used where very complex roof shapes must be covered.

Construction

Panels are generally fixed to timber battens or purlins, with screws or nails placed at the step of each course where the next sheet covers them, or through the top of the profile. Side laps engage or overlap by a profile. Matching ridge, hip, gable and valley pieces complete the roof.

Characteristics

• Much lighter than clay or concrete tile, reducing structural load.
• Quick to install over large areas.
• The deep three-dimensional profile hides minor dents and stiffens the sheet.
• Exposed or semi-exposed fasteners need correct washers and positioning.
• Thermal movement is accommodated mainly at laps and fixings, so manufacturers limit sheet lengths.

Durability

Life depends mainly on the metallic coating (zinc, aluminium-zinc or zinc-aluminium-magnesium), the paint or granule system, the environment and the condition of cut edges and fixings.