Greenhouse Structural Components Greenhouse Management Structural Components

Greenhouse Structural Components Greenhouse Management

Structural Components n n Greenhouses are made by assembling different parts or components. Each part has a specific role in the overall greenhouse structure.

This slide shows the basic components of a greenhouse

Side Posts n n n Support the trusses and bear the weight of the greenhouse. Set in concrete footings. Typically spaced 10 feet apart.

Curtain Wall n n The first several feet of sidewall above the soil line. Usually made of some solid building material such as poured concrete, concrete blocks, bricks, or treated lumber.

Sill n The top of the curtain wall

Eave n n Where the sides of the greenhouse join the roof of the greenhouse. The “top” of the sides of the greenhouse.

Truss n n Structural component that supports the weight of the greenhouse roof. Consists of rafters, struts, and chords.

Purlin n n Purlins run the length of the greenhouse. Keep the roof trusses aligned.

Ridge n n Where the roofs come together at the top of the greenhouse. Many greenhouses have a ridge vent(s).

Sash Bars purlin n n Run perpendicular to the purlins. Attached to the purlins. Hold the glazing in place. Sometimes built with a drip groove or channel to catch condensation that forms on the inside of the glass panels. sash bars

Wooden Sash Bar Close-up Sash bar cap Glass panels Sash bar Drip groove

Aluminum Sash Bar Close-up

Sash Bar Cap Bar cap n n Fastened to the sash bars with screws. Functions to hold the glass panels in place.

Siting a Greenhouse n Topography n n Select as level a site as possible. Amount of land n n The general “rule of thumb” is to purchase at least twice as much land as the desired growing area. For example, you desire to build a ridge & furrow greenhouse measuring 50 feet x 150 feet. n 7, 500 square feet x 2 = 15, 000 square feet =. 34 acres

Greenhouse Orientation N W n n E S Depends on latitude and whether the greenhouse is connected or detached. Single, detached greenhouse: n In northern latitudes an east-west orientation is favored because light can enter through the sides rather than through the ends of the greenhouse where it would cast more shade. n Also, because our winds are predominately from the west (blue arrow) this positions an end wall of the greenhouse into the wind.

Greenhouse Orientation n Connected Greenhouses: n South An east – west orientation is not ideal. North

Greenhouse Orientation n Connected Greenhouses: n A north – south orientation is BEST! South North

Windbreaks n n n Planted on the north and west sides of the greenhouse. Help reduce heat loss from the greenhouse. Greenhouses should be located a minimum of 100 feet away.

Framing Materials n Two basic kinds of material: n n Wood Metal; primarily aluminum or aluminum alloys

Wood n n Redwood, cedar, or some other rot-resistant wood. Treated wood. n Beware of mercury-based paints and preservatives because fumes from these products are toxic to plants.

Aluminum n n Lightweight Strong Rust resistant Framing materials can be manufactured thinner and be spaced further apart allowing for minimal shading.

Stresses on the Greenhouse n n Weight of the framing and glazing. Snow loads. Wind pressure. Temperature; fluctuating temperatures cause expansion and contraction of framing and glazing materials.

Headhouse Head House n n Service building with overhead doors. Used for planting, media preparation and storage, chemical storage, container storage and office space, etc.

Headhouse, continued… n n May also include the heating plant (boiler) and a cold storage facility. Should be at least 10% of the total growing area of the greenhouse.

The End