Greenhouses?

[Duck Slipper]

Exactly cnycharles. I contacted GH supply companies and none could supply a set of plans and materials lists for a given size. Even talked with a contractor and he had no luck.
Example; Plans for a 14’ x 20’ polycarbonate and treated lumber GH...materials list for all the needed poly attachments, fittings, corner end pieces, etc. No such thing.

 

[Ray]

I think you're just going to have to be a bit self-sufficient in that regard.

My 14' x 18' Turner Greenhouse had arches every 2' of length, with gussets at each intersection and a cross-brace between the opposite intersections of the wall and root panels. There were ties that ran the length of the structure, at the base, the eaves and the roof peak. the end panels of the sides and roof had diagonal braces for rigidity. The north end was wood and plywood, insulated with styrofoam, and the front had similar 2' spacing surrounding the door using the same steel angle used for the sides and roof.

When I bought it, it came with 28" wide acrylic panels that ran vertically, overlapping and attached to the arches using metal straps that were attached to the frame with bolts. I later replaced them with multiwall polycarbonate that was 48" wide. The channels that jointed the panels had a 1/2" gap in the middle that lined up with the frame, making them easy to attach with self-tapping screws that had rubber washers on them.

 

[abax]

I'n sorry Ozpaph. I had photos on a computer that crashed without warning. I lost all those photos. We used 4x6 treated
lumber for the posts and 2x4 for underpining the wire. Then attached the "rollers" to the 2x6 posts. The hardest part
was stretching the fencing wire. I think we used the 2x4s every two feet under the wire on an 8' bench. We also built
three step benches for non-orchid plants, but I don't remember the details. We designed and built my 12'x28' greenhouse
20 years or more ago and I don't remember a lot of the details of construction.

 

[ScientistKen]

What you run into with larger with wood framed greenhouses is that wider becomes more difficult to do with rafters. You might be better off with trusses after a point. 12 ft should be fine with rafters. With a longer greenhouse, you end up having potential issues with your ridge board. If not sufficiently supported it will want to sag. The big advantage for wooden greenhouses is they are easy to insulate and more DIY people are familiar with working with lumber as a building material.

The main issue I had was that my rafters got really hot. They appeared as if they were slightly burned over time. White paint might help with that.

The arch based greenhouses are designed to support the width and for length you just add more arches. I have never built that kind of greenhouse. I would expect them to be difficult to insulate and difficult to glaze if you are not using rolled plastic.

 

[LWP]

Frame: 22 x 48 PT lumber. 14 ft center ridge, 10ft sidewalls. 4 x 4 posts for uprights on 10 ft centers. 2 x 6 x's roof rafters on 3 ft centers, 2 x 6 cross rafters on 10 ft centers, and wall framing on 2 ft centers. Built by myself with no outside assistance.

Exterior: Sidewalls are 13cm double polycarbamate, roof inflated double poly, white 50%. Will remove top layer of white poly and replace with clear to improve lighting this spring. I can control light levels in summer with lite coats of 1 part white latex exterior white paint, diluted with 3 parts water, till I get the light levels right.

Heat: Two 120,000 BTU Modine propane heaters. This gives an operational heat capacity of 60 degrees night with 10 degree outside temp to maintain a night temp of min 55 degrees. I have the second heater as a backup in case the primary fails and it is set to fire at 50 degrees. I also have a generator should power fail, 4 - 36,000 BTU 'Kerosun' kerosene heaters and have irrigation foggers if all else fails.

Cooling: 4 ft x 22 ft x 4 inch Kool Cell pad recirculating evaporative system system. Exhaust fans are 30 inch, 2 stage attic exhaust fans rewired for reverse airflow and staged to operate in 5 degree intervals (80, 85, 90 and 95).

Greenhouse has run for 26 years with no structural issues in zone 7,

 

[Ozpaph]

I'n sorry Ozpaph. I had photos on a computer that crashed without warning. I lost all those photos. We used 4x6 treated
lumber for the posts and 2x4 for underpining the wire. Then attached the "rollers" to the 2x6 posts. The hardest part
was stretching the fencing wire. I think we used the 2x4s every two feet under the wire on an 8' bench. We also built
three step benches for non-orchid plants, but I don't remember the details. We designed and built my 12'x28' greenhouse
20 years or more ago and I don't remember a lot of the details of construction.

Thank-you for looking.

 

[Duck Slipper]

Thanks for everyone’s input. Really do appreciate it!

 

[awesomei]

Awesomei,
What kind of heat are you using? Emergency heat?

Elecrtic! switching to propane