How To Build a Fiberglass Greenhouse

Greenhouse Construction Tips

Great greenhouse tips and useful information to
keep your greenhouse running efficiently.


  ::Garden Tips

How To
Build With Fiberglass

any good quality wood for your greenhouse framework.
Be sure to treat the pieces with a wood preservative
before assembly, even cedar or redwood. Copper
or zinc based preservatives are safest.

2 x 4 lumber is adequate for framing, but use heavier lumber in snow zones
or where rafter length is more than 8 ft. (Check your local building

3. Space rafters and
studs 2 ft. apart and install blocking every 24″ to 36″ in walls and
between rafters.

Flat fiberglass is rolled out horizontally on roof, but can be installed
either horizontally or vertically on walls. (Corrugated fiberglass should
always be installed vertically.)

Caulk all fiberglass seams.

Secure flat fiberglass with wood lath on rafters and studs (no horizontal
lath). Nail fiberglass to blocking with aluminum washer-head

7. Provide for
ventilation with an exhaust fan system, or large vents in

Notes for Fans & Shutters

For the

Frame wall openings
square and 1/2″ larger than fan blade and shutter sizes.

finished sunroom:

Frame rough openings
3-1/2″ larger than fan and shutter size. Line opening with 2×4, offset
enough toward outside to project past siding. Install fan or shutter.
Finish inside by lining rough opening with 1×3.

Solar-Powered Vent Controls

These “top of
the line

controls will open and close greenhouse vents automatically without
Bayliss vent openers convert
energy from the warmth of the sun into mechanical energy to open vents.
The hotter it gets, the wider the vents are opened.

Materials: Bayliss openers are made from
the best corrosion resistant materials: brass, stainless steel and
satin-anodized aluminum. They are designed to give many years of service,
are covered by a 2-year guarantee, and can be repaired should the need

Capacity: The Bayliss
can exert
a force of 14 lbs. at the point where it is attached to the vent. A
threaded adjuster bolt can set the Bayliss to start opening the vent at
temperatures between 55º F and 75º F. Maximum opening of 12″ is reached at
approximately 20º F above the starting temperature.

Openers can be
installed in a series on a long vent to replace worn out electric vent
motors. The adjuster bolt can equalize the loading
so the lifters work
in unison.

Installation: Easy to install with
screws: top arm to vent, bottom arm to greenhouse frame. Illustrated
directions included. Openers are about 12″ long and fit neatly up close to
the glass.


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