Question | Answer |
Rafter | Support for the roof that is perpendicular (--l) to the ridge, eave, and purlins |
Ridge | The highest point of the roof where two sloping surfaces (rafters) meet |
Purlin | Parallel (ll) to the ridge and eave. Between the ridge and eave. |
Gusset | A bracket or plate used to reinforce joints in the structure |
Collartie | Between the rafters to help keep the rafters from moving apart (stablizes) |
Eave | Lower edge of roof |
Gable | The end surface of the ridged roof |
Endwall | Wall under Gable |
Sidewall | Wall under the eave |
Diagonal roof brace | Provide support to keep the greenhouse frame rigid |
Diagonal wall brace | Provide support to keep the greenhouse frame rigid |
What style of greenhouse is this? | Gutter connected greenhouse |
What are the advantages of having trusses rather than rafters for a greenhouse roof? | -can be up to 60' wide (approx 20m) with trusses vs 25' wide (approx 8m) with rafters -clear span (no support posts) |
Identify the the highlighted portion of the truss | Web members |
Identify the highlighted portion of the truss | Bottom chord |
Identify the highlighted portion of the truss | Top chord |
Identify the highlighted portion of the truss | Gussets |
What style foundations are used for greenhouses? | Poured concrete, concrete block Concrete post or pressure treated wood post |
Describe free standing greenhouse | An independent structure not attached to another greenhouse |
Describe gutter connected greenhouses | Aka ridge and furrow/ridge and gutter Attached at the eave (gutter) eg like townhouses |
List 5 advantages of gutter connected greenhouses | -saves space -lower heating costs (shared walls) -lower servicing costs ie gas lines -convenient and efficient for moving between greenhouses -lower costs for cover as inside walls either not covered, or covered with plastic |
List 3 disadvantages of gutter connected greenhouses | -difficult to control snow load in gutters -insect and disease spreads easier if sidewalls aren't covered -inside walls may be covered to allow different environments |
How far down should foundations extend? | Below the frost line (18") |
Why do you need an adequate foundation for a greenhouse structure? | To support weight of the GH, weight of crop load and snow load, and resist excessive wind. |
Increasing the depth of foundation will increase the load capacity by ________ depending on soil conditions. | 5-8 times |
What style of greenhouse is this? | Standard peak design |
What style of greenhouse is this? | Gothic arch |
What style of greenhouse is this? | Quonset |
List 4 advantages of standard peak GH | -Can be 60' clear span -flat surfaces can be covered with rigid plastic or glass -suitable for ridge and furrow range -ease of construction |
List the disadvantages of standard peak GH | -Excessive shading from truss system -steel or aluminum reduce shading, but are expensive -needs a suitable foundation to resist wind load |
What style of greenhouse is this? | Rigid frame |
List advantages of rigid frame GH | -high strength per unit of wood used -clear span up to 40', minimal shading -suited for ridge and furrow |
List disadvantages of rigid frame GH | -expensive foundation to resist wind load -not as wide as post and truss |
List advantages of Gothic arch GH | -simple, inexpensive construction -good height near side walls -plastic or rigid plastic may be used -clear span |
List disadvantages of Gothic arch GH | -height increases wind load -more heat loss because of height of walls -not suited for ridge and furrow -pre fab packages are limited -width is restricted by height |
What style GH is this? | Gothic arch |
List advantages of Quonset GH | -simple, efficient, inexpensive construction -clear span up to 40' -one piece plastic cover, single or double inflated -minimal shading from structure -many types of pre fab -ideal for low crops eg bedding plants, GH lettuce |
List disadvantages of Quonset GH | -not suited to ridge and furrow -snow build up is possible -side wall height is restricted, not suited to taller crops |
What are the 3 GH structural materials? | Wood Aluminum Steel |
List advantages of wood as a building material | Inexpensive Local supply |
List disadvantages of wood as a building material | -Labour to construct -Less strength, so need more material which increases shading -short life span (rots) -should be painted white for good light reflection |
List advantages of aluminum as a building material | -Looks good -low maintenance -high strength -simple construction -light weight, suitable for glazing bars and vent frames in all greenhouses |
List disadvantages of aluminum as a building material | -Expensive -not available in local market |
List advantages of steel as a building material | -strongest -same attributes as aluminum |
List disadvantages of steel as a building material | -Same as aluminum -must be painted or galvanized to prevent rust |
Want to create your own Flashcards for free with GoConqr? Learn more.