Fit every frame, match every structure
A key to successful greenhouse production is a well-planned greenhouse structure and a reliable glazing system.
Among the traditional options for greenhouse covers, polycarbonate sheet offers versatility and efficiency, since it can be cold bent to retrofit greenhouse frames that were designed for PE films, and can be tailor made to retrofit glasshouses that experienced hail and/or debris damage.
Both corrugated and multiwall polycarbonate glazing systems can suit any gutter connected (ridge and furrow) or free standing greenhouse frame.
Gothic Arch
- Efficient design, eliminates the need for structural trusses.
- Common configurations in subtropical climates.
- Gables consist of two arches that meet at the ridge.
- Optional Configurations: With/without roof windows.
- Common span between gutters: 9.6 meters to 11.2 meters (30 feet to 40 feet).
Compatibility with polycarbonate sheet
- One polycarbonate sheet spans from ridge to gutter, with purlins spanned according to required load bearing.
- Window and ridge cap elements are available.

Saw-tooth gable
- Composed of two inclines or arches of different heights and lengths with a fixed open vent between.
- Common span between gutters: 6 meters to 12 meters (20 feet to 40 feet).
- Common in desert regions and tropical climates, where open ventilation is required.
- Typically designed for PE film but can easily be retrofitted using corrugated or multiwall polycarbonate sheets.
Compatibility with polycarbonate sheet
- One for each slope, polycarbonate sheet, ridge to gutter.

Even span / A-frame gable
- A very simple design of two slopes of equal pitch and width.
- A very strong and firm structure. Suitable for heavy wind / snow loads.
- Common span between gutters: 9.6 meters to 11.2 meters (30 feet to 40 feet).
- Most common configuration for cold and temperate climates.
Compatibility with polycarbonate sheet
- A common glasshouse structure which can easily be retrofitted with corrugated polycarbonate sheets without any structural modifications.
- One polycarbonate sheet spans from ridge to gutter, with purlins spanned according to required load bearing.
- Windows and ridge cap elements are available.

Quonset arch
- A basic design of a bent arch built with steel pipe or square steel tubing
- Usually spans are 6-10 meters (20-33 feet), but wider arches are common.
- Allows excellent solar energy penetration
Both corrugated and multiwall polycarbonate sheets with attention to few important details:
- The sheets are bent within the allowed bending radius. To access our bending radium calculator click here
- A uniform arch all around
- Ridge purlin
- One sheet gutter-to-gutter installation is possible, as long as guidelines are maintained to prevent residual stress.

Wide-span
- Two moderate, long inclines that create a wide open structure without internal support columns.
Advantage: Large, column free, open area. Suitable for garden centers , sprouting plants, storage areas, work areas with conveyors or large volume equipment
Compatibility with polycarbonate sheet
- Each incline is made up of a either one sheet ridge-to-gutter, or number of overlapping sheets, depending on required length.

Tabular Summary of Greenhouse Frame Types
Saw tooth gable | Gothic arches | Even span /A-frame gable | Quonset gable | Wide span |
---|---|---|---|---|
Light construction | Light and economic frame | Robust construction for extreme wind and snow loads | Light construction | Robust construction for extreme wind and snow loads |
Light loads | Medium to high loads | Suitable for extreme climates | Light loads. Not suitable for high snow loads | Suitable for extreme snow and wind loads |
Fixed roof ventilation | Various optional window configurations | Various window configurations | Various window configurations | Various window configurations |
Simple and easy installation | Simple and easy | Simple and easy. Designated system accessories can adapt the covering to carry extreme loads. | Either one sheet gutter-to-gutter installation, or any other configuration is possible | Simple and easy. Must follow recommended guidelines. . Designated system accessories can suit the cover to carry extreme loads. |
Suitable for tropical and sub-tropical climates | Suitable for tropical, subtropical and temperate climates | Suitable for any climate | Suitable for subtropical climate | Suitable for any climate |
Simple retrofit from PE to corrugated polycarbonate | Simple retrofit from PE to corrugated polycarbonate | Heavy duty | Arch radius should be no less than 4 m (13.1 ft.) | Creates a large working space free of obstructions. Large air volume: requires more energy to heat/cool |
ONE SOURCE FOR ENGINEERING GUIDANCE & TECHNICAL SUPPORT
The Palram team provides services to support an array of agricultural & horticultural segments. We accompany you from the specification of the most suitable solution, through the planning through to adaptation and successful implementation.
