A pergola can remain as an open framework of beams or be given a partial or complete roof to provide shade and weather protection for the outdoor space beneath. The choice of roofing approach depends on how much shelter is wanted, the aesthetic of the pergola and garden, and the budget available.

Open Beam Roof

The traditional pergola roof is an open lattice of crossbeams and purlins that provides dappled shade and a structure for climbing plants without creating a weatherproof covering. The beams are typically 100mm by 50mm or larger, spaced at 300 to 500mm centres to achieve the desired shade density. This approach requires no additional covering material, is the simplest to construct, and creates the classic pergola appearance. Adding climbing plants over time creates increasing shade and visual interest.

Polycarbonate Roof Panels

Twin-wall or multiwall polycarbonate panels fixed across the pergola beams create a weatherproof covering that still admits a significant amount of daylight. Polycarbonate panels are available in clear, opal, or bronze tints and provide UV protection as well as rain shelter. They are lightweight, easy to cut and handle, and can be fixed across the top of the pergola beams using appropriate capping and sealing profiles. A fall of at least 5 degrees is needed to drain rainwater reliably off the polycarbonate surface.

Glass Roof

Laminated or toughened safety glass fixed to the pergola frame provides the most premium appearance and transmits the most light. Glass requires a structural frame capable of carrying its weight and is typically used on more substantial pergola or garden room structures with welded steel or engineered timber frames rather than simple garden structures. A professional glazing company should be involved for any glass roof installation.

Retractable Canopy

A retractable fabric or aluminium canopy provides flexible shade that can be deployed when needed and retracted when full sun is wanted. Retractable systems are available as DIY kits for standard pergola widths or as custom-made systems. They require a more robust fixing structure as the opening and closing mechanism places different loads on the frame than a static covering.

Summary

A pergola roof ranges from traditional open beams for shade and plant support to polycarbonate panels for weatherproofing, glass for a premium finish, or a retractable canopy for flexibility. Polycarbonate is the most practical DIY option for most pergola roofing projects. Any roof must have adequate drainage fall. Check planning position if the pergola becomes substantially enclosed.