Resources
Pergola & Outdoor Structure Glossary
Plain-English definitions of the terms that come up when you design a pergola, pavilion, or covered structure — from louvered roofs and footings to cedar and ledger boards.
Pergola
A pergola is an outdoor structure with vertical posts that support an open roof of cross-beams and rafters, giving filtered shade rather than full cover.
Pavilion
A pavilion is a freestanding outdoor structure with a full pitched roof, providing complete protection from rain and sun.
Gazebo
A gazebo is a freestanding, roofed garden structure, traditionally octagonal, used as a focal point and shaded sitting area.
Arbor
An arbor is a small arched or flat-topped garden structure, usually framing a path or gateway and supporting climbing plants.
Louvered Roof
A louvered roof is a pergola roof of rotating slats that open for sun and close for full rain protection.
Bioclimatic Pergola
A bioclimatic pergola is a louvered aluminum pergola whose adjustable roof manages sun, shade, and ventilation to control the microclimate beneath it.
Motorized Pergola
A motorized pergola has a powered louvered roof — and sometimes screens — controlled by remote, app, or rain and wind sensors.
Cedar
Cedar is a rot- and insect-resistant softwood — usually western red cedar — that is the traditional premium wood for pergolas and pavilions.
Pressure-Treated Pine
Pressure-treated pine is softwood lumber infused with preservatives to resist rot — the cheapest pergola material, but prone to warping and graying.
Vinyl Pergola
A vinyl pergola is built from PVC components, giving a clean white wood-look finish with virtually no maintenance.
Aluminum Pergola
An aluminum pergola is built from powder-coated aluminum — rust-proof, low-maintenance, and strong enough to span wide openings and carry motorized louvers.
Rafter
Rafters are the evenly spaced top members of a pergola that run across the beams to form the open roof and cast the shade pattern.
Beam
Beams are the main horizontal members of a pergola that sit on the posts and carry the rafters and roof load.
Ledger Board
A ledger board is the board that fastens an attached pergola or roof to the house wall, and must be flashed to keep water out.
Footing
A footing is the concrete foundation poured below the frost line that supports a pergola or pavilion post and keeps the structure level.
Frost Line
The frost line is the maximum depth ground freezes in winter; footings are poured below it so frost heave can’t move the structure.
Post Anchor
A post anchor is the galvanized metal bracket that fastens a pergola post to a concrete footing, patio, or deck frame.
Tongue-and-Groove
Tongue-and-groove boards interlock edge-to-edge to form the smooth, finished ceiling common in cedar pavilions.