A pergola beam is a horizontal beam that forms the top of a pergola, running from post to post or extending beyond the posts. Together, the beams form the open roof frame of a pergola, over which climbing plants can grow or a shade sail can be attached.
Characteristics
A pergola has no solid roof covering — the pergola beams are the roof. The beams are evenly spaced and provide:
- Shade (partial)
- A structure for climbing plants
- A visual framework for the outdoor space
Dimensions
| Span | Beam dimension (indicative) | Beam spacing |
|---|---|---|
| Up to 3 m | 50 x 150 mm | 40-60 cm |
| 3-4 m | 75 x 175 mm | 50-70 cm |
| 4-5 m | 75 x 200 mm | 60-80 cm |
The beam ends often extend 30-50 cm beyond the posts (overhang), sometimes with a decorative finish (rounded, angle-cut, or profiled).
Timber species
- Douglas fir — Most popular choice, attractive colour, durable outdoors
- Larch — Comparable to Douglas fir
- Pressure-treated softwood — Budget option
- Hardwood — Longest lifespan
Related terms
- Post
- Purlins
- Overhang
- Douglas fir timber