Can you curve multiwall polycarbonate roofing sheets?

Multiwall polycarbonate roofing sheets are available in a range of thicknesses from 4 to 10 and 16mm which are ideally suited to cold curving into arches.  The multiwall sheets can be easily curved for the formation of architectural rooflights, including arched walkways, barrel vaults and domed rooflights.

NB. Polycarbonate sheets must always be bent longitudinally, never across the width of the sheet, for a roofing application i.e. the ribs must run over the top of the curve.

Multiwall polycarbonate can be cold curved only in the direction of extrusion. Although good design practice should limit the cold curve radius to 175 times the sheet thickness, the minimum cold curve radius is equal to 150 times the sheet thickness. For sheets with more complex structures the minimum bending radius must be increased to prevent optical distortion of the internal walls.

Curving sheets to a tighter radius than this leads too buckling and stress levels which will reduce the impact resistance and service life of the sheet. It will also make it more prone to chemical attack.

Only sheets of 16mm and below are suitable for cold curving. Curving of sheets thicker than this leads to optical distortion and high levels of internal stress.