Greenhouse Structural Greenhouse Structural ComponentsComponents

Greenhouse ManagementGreenhouse Management

Structural ComponentsStructural Components

Greenhouses are made by assembling different Greenhouses are made by assembling different parts or components.parts or components.

Each part has a specific role in the overall Each part has a specific role in the overall greenhouse structure.greenhouse structure.

This slide shows the basic This slide shows the basic components of a greenhousecomponents of a greenhouse

Side PostsSide Posts

Support the trusses and bear the weight of the Support the trusses and bear the weight of the greenhouse.greenhouse.

Set in concrete footings.Set in concrete footings. Typically spaced 10 feet apart.Typically spaced 10 feet apart.

Curtain WallCurtain Wall

The first several feet of sidewall above the soil line.The first several feet of sidewall above the soil line. Usually made of some solid building material such as Usually made of some solid building material such as

poured concrete, concrete blocks, bricks, or treated poured concrete, concrete blocks, bricks, or treated lumber.lumber.

SillSill

The top of the curtain wallThe top of the curtain wall

EaveEave

Where the sides of the greenhouse join the roof of the Where the sides of the greenhouse join the roof of the greenhouse.greenhouse.

The “top” of the sides of the greenhouse.The “top” of the sides of the greenhouse.

TrussTruss

Structural component that supports the weight of the Structural component that supports the weight of the greenhouse roof.greenhouse roof.

Consists of rafters, struts, and chords.Consists of rafters, struts, and chords.

PurlinPurlin

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

RidgeRidge

Where the roofs come together at the top of the Where the roofs come together at the top of the greenhouse.greenhouse.

Many greenhouses have a ridge vent(s).Many greenhouses have a ridge vent(s).

Sash BarsSash Bars

Run perpendicular to Run perpendicular to the purlins.the purlins.

Attached to the purlins.Attached to the purlins. Hold the glazing in Hold the glazing in

place.place. Sometimes built with a Sometimes built with a

drip groove or channel drip groove or channel to catch condensation to catch condensation that forms on the inside that forms on the inside of the glass panels.of the glass panels.

purlin

sash bars

Wooden Sash Bar Close-upWooden Sash Bar Close-up

Sash bar

Glass panels

Drip groove

Sash bar cap

Aluminum Sash Bar Close-upAluminum Sash Bar Close-up

Sash Bar CapSash Bar Cap Fastened to the sash bars Fastened to the sash bars

with screws.with screws. Functions to hold the Functions to hold the

glass panels in place.glass panels in place.

Bar cap

Siting a GreenhouseSiting a Greenhouse

TopographyTopography Select as level a site as possible.Select as level a site as possible.

Amount of landAmount of land The general “rule of thumb” is to purchase at least The general “rule of thumb” is to purchase at least

twice as much land as the desired growing area.twice as much land as the desired growing area. For example, you desire to build a ridge & furrow For example, you desire to build a ridge & furrow

greenhouse measuring 50 feet x 150 feet.greenhouse measuring 50 feet x 150 feet. 7,500 square feet 7,500 square feet x 2x 2 = 15,000 square feet = .34 acres = 15,000 square feet = .34 acres

Greenhouse OrientationGreenhouse Orientation

Depends on latitude and whether the greenhouse is connected or detached.Depends on latitude and whether the greenhouse is connected or detached. Single, detached greenhouse:Single, detached greenhouse:

In northern latitudes an east-west orientation is favored because light In northern latitudes an east-west orientation is favored because light can enter through the sides rather than through the ends of the can enter through the sides rather than through the ends of the greenhouse where it would cast more shade. greenhouse where it would cast more shade.

Also, because our winds are predominately from the west (blue arrow) Also, because our winds are predominately from the west (blue arrow) this positions an end wall of the greenhouse into the wind.this positions an end wall of the greenhouse into the wind.

WE

S

N

Greenhouse OrientationGreenhouse Orientation

Connected Greenhouses:Connected Greenhouses: An east – west orientation An east – west orientation is not idealis not ideal..

NorthSouth

Greenhouse OrientationGreenhouse Orientation

Connected Greenhouses:Connected Greenhouses: A north – south orientation is BEST!A north – south orientation is BEST!

North

South

WindbreaksWindbreaks

Planted on the north and west sides of the Planted on the north and west sides of the greenhouse.greenhouse.

Help reduce heat loss from the greenhouse.Help reduce heat loss from the greenhouse. Greenhouses should be located a minimum of Greenhouses should be located a minimum of

100 feet away.100 feet away.

Framing MaterialsFraming Materials

Two basic kinds of material:Two basic kinds of material: WoodWood Metal; primarily aluminum or aluminum alloysMetal; primarily aluminum or aluminum alloys

WoodWood

Redwood, cedar, or some other rot-resistant Redwood, cedar, or some other rot-resistant wood.wood.

Treated wood.Treated wood. Beware of mercury-based paints and preservatives Beware of mercury-based paints and preservatives

because fumes from these products are toxic to because fumes from these products are toxic to plants.plants.

AluminumAluminum

LightweightLightweight StrongStrong Rust resistantRust resistant Framing materials can be manufactured Framing materials can be manufactured

thinner and be spaced further apart allowing thinner and be spaced further apart allowing for minimal shading.for minimal shading.

Stresses on the GreenhouseStresses on the Greenhouse

Weight of the framing and glazing.Weight of the framing and glazing. Snow loads.Snow loads. Wind pressure.Wind pressure. Temperature; fluctuating temperatures cause Temperature; fluctuating temperatures cause

expansion and contraction of framing and expansion and contraction of framing and glazing materials. glazing materials.

HeadhouseHeadhouse

Service building with overhead doors.Service building with overhead doors. Used for planting, media preparation and storage, Used for planting, media preparation and storage,

chemical storage, container storage and office space, chemical storage, container storage and office space, etc.etc.

Head House

Headhouse, continued…Headhouse, continued…

May also include the heating plant (boiler) and May also include the heating plant (boiler) and a cold storage facility.a cold storage facility.

Should be at least 10% of the total growing Should be at least 10% of the total growing area of the greenhouse.area of the greenhouse.

The EndThe End