Greenhouse Structures
 What does your house provide you with?
 What are the important features of a
home that provide these things?
 What should a greenhouse provide
plants?
 What features could provide these
things?
Student Learning Objectives
 1. Identify greenhouse designs.
 2. Identify considerations for greenhouse
frameworks.
 3. Identify and describe greenhouse
glazing materials.
Objectives Cont.
 4. Describe the functions of the
headhouse.
 5. Discuss the advantages of retractableroof greenhouses.
 6. Describe greenhouse bench options.
Terms







Acrylic structured sheets
Bench
Even-span greenhouse
Fiberglass
Glass
Glazing
Greenhouse
Terms







Greenhouse framework
Headhouse
Hoop-house
Lean-to greenhouse
Polycarbonate structured sheets
Polyethylene
Retractable-roof greenhouse
Terms




Ridge-and-furrow greenhouse
Rolling bench
Structured sheets
Uneven-span greenhouse
What are the common
greenhouse types?
 A greenhouse is a structure enclosed by
glass or plastic that allows light
transmission for the growth of plants.
There are four basic styles of
greenhouse design.
 The lean-to greenhouse shares a wall
with a building and relies on the
building structure to provide support for
the roof.
Lean-to Greenhouse
Courtesy, Interstate
Publishers, Inc.
 Even-span greenhouse structures are
single houses that have roofs with an
even pitch and an even width. A
common even-span greenhouse that
uses arching pipes for the framework is
called a hoop house.
 Even Span
Greenhouse
 Hoop house
 Uneven-span greenhouses have
unequal pitches and widths. Use of this
style is limited to hillsides.
 Ridge-and-furrow greenhouse
structures consist of a number of
greenhouses connected along the
length of the house.
 Uneven Span
Greenhouse
 Ridge and Furrow
Greenhouse
Create a Greenhouse
 Use the marshmallows and toothpicks to
create a greenhouse of one of the styles
we have just discussed.
What considerations need to be
addressed for greenhouse
frameworks?
 The greenhouse framework supports
the greenhouse covering material.
 The framework should be strong, yet
allow the maximum amount of light to
reach the plants.
 Aluminum and aluminum/steel
 long lasting, low maintenance
 Wood
 Not used much anymore
 Angle iron
 Ornate but heavy
 Plastics
 Cheap but light and easily broken
What materials are used for
greenhouse glazing?
 The covering of the greenhouse is
referred to as the glazing.
 Considerations include:
 Durability
 Light transmission
 Cost
 Heating costs
 Flexible sheets of polyethylene are
stretched over the greenhouse
framework.
 Structured sheets, including
polycarbonate, acrylic, and fiberglass,
which are made with double walls offer
good insulation.
 Polyethylene
 Good
insulator
 Cheap
 Flexible
 Lasts 5-7
years
 Polycarbonate structured sheets
 Most widely used
 Good light transmission
 Resist hail damage
 Easy to work with.
 Polycarbonate
sheets
 Box shaped
tubes
 Acrylic structured sheets
 High light transmission
 Cost more than polycarbonate sheets
 Prone to hail damage
 Less flexible than polycarbonate
 Solid plastic
sheets
 Fiberglass
 Dropped in popularity
 Discolors after 7-10
years
 Flammable
 Poor insulator
 Glass
 Best material for crop production
 Highest light transmission
 Long lasting
 Expensive
 Breakable
What are the functions of the
headhouse?
 Headhouse
 Supports the
production of
greenhouse
crops
 Attached to
greenhouse




Storage area
Potting area
Office
Shipping area
What are the advantages of
retractable-roof greenhouses?
 Retractable-roof greenhouse
 Allow the roof to be opened and
closed.
 Open the roof when weather conditions
are favorable
 Close the roof when crops need
protection
 Provide plants with increased light levels
and fresh air
 Prepare outdoor crops for elements before
leaving the greenhouse
 Reduced disease problems
 Better ventilation
 Reduced irrigation
 Rainfall
 More effective temperature control for DIF.
What are greenhouse bench
options?
 Bench
 Structure that holds
the plants above the
ground.
 Arranged with
aisle space and
growing space in
mind
 Made of
 expanded
galvanized steel
 Aluminum
 Plastic
 Rot resistant wood
 Rolling benches maximize growing
space by limiting space for aisles. The
benches are placed on pipes, which
allows them to be easily moved from
side to side.
 Bench layouts
 conventional
 Peninsular
 Movable benches
Review/Summary
 What are the common greenhouse
sizes?
 What considerations need to be
addressed for greenhouse frameworks?
 What materials are used for greenhouse
glazing?
Review/Summary cont.
 What are the functions of the
headhouse?
 What are the advantages of retractableroof greenhouses?
 What are greenhouse bench options?