greenhouse shelves

habitat_gardener · February 9, 2015

Thinking out loud here.

We're building this 7x8 ft. greenhouse, which has side walls just over 4 ft. high and the peak just under 8 ft. high.
http://www.bepasgarden.com/greenhouseplans.html
(scroll down to see photos)

The plan calls for 2 shelves (each 8 ft. long), but I think I need more shelves. I plan to use the greenhouse primarily to grow from seed.

I'm looking for opinions (and photos! if you have them) on how many shelves to put in. I'm leaning toward 2 shelves on the southerly side, and will keep a single shelf at comfortable potting-table height on the northerly side. Or vice versa. So when I have a lot of potted-up seedlings, I can use the floor space and all of the shelves -- 40 linear feet @ 2 ft. wide. Is an extra shelf a good idea, or should I just go with one shelf on each side?

Also, the plans call for six 2x3s, each 8 ft. long, per 2-ft. wide shelf. That seems overbuilt to me. Since I will be using seed flats, not gallon or larger pots, I think three 2x3s will suffice. Or maybe use hardware cloth?

In this plan, the shelves help make the structure sturdier, so we need to put in at least one permanent shelf on each side.

Rairdog · February 11, 2015

I would leave the shelves as is. They give you a nice sturdy place to up-pot, hold water buckets etc... Plans change. You may want to bring some bigger pots in to nurse them back to health. You could add a couple wire closet shelves above/below. Then you could remove the brace so they fold down. This gives you a place to germinate more trays with the ability to fold them down so you don't shade the wood shelves.

Other options. You can put diagonal strap bracing on the corners for shear strength. It is what they use on outside corners of homes when they are just foam and vinyl siding to meet wind ratings. Simply put the polycarb right over them.

If you have any snow load(not sure where in CA you are located) I would consider a collar tie 1/3 or so from the top. The ridge beam will want to sag and it will push out the sidewalls.

KarenO · February 11, 2015

Fixed shelving really limits your options for growing anything bigger than seedlings or small herbs. Perhaps consider bracing the greenhouse itself on the inside with cross bracing for example and then using modular/removable resin or metal storage shelving that you can move around to suit you for different purposes. In my small greenhouse I use resin shelving hip height in a "u" shape around the greenhouse for seedlings then remove most of it (and store it taken apart) to grow full sized tomatoes, cucumbers and peppers from soil to ceiling through summer till fall.
My GH is 8.5 x8.5 square with the ceiling center 8"
KarenO

habitat_gardener · February 12, 2015

Good ideas! We'll look into diagonal bracing, and other shelf options.

February 9, 2015	#1
habitat_gardener Tomatovillian™ Join Date: Apr 2008 Location: California Central Valley Posts: 2,543	greenhouse shelves Thinking out loud here. We're building this 7x8 ft. greenhouse, which has side walls just over 4 ft. high and the peak just under 8 ft. high. http://www.bepasgarden.com/greenhouseplans.html (scroll down to see photos) The plan calls for 2 shelves (each 8 ft. long), but I think I need more shelves. I plan to use the greenhouse primarily to grow from seed. I'm looking for opinions (and photos! if you have them) on how many shelves to put in. I'm leaning toward 2 shelves on the southerly side, and will keep a single shelf at comfortable potting-table height on the northerly side. Or vice versa. So when I have a lot of potted-up seedlings, I can use the floor space and all of the shelves -- 40 linear feet @ 2 ft. wide. Is an extra shelf a good idea, or should I just go with one shelf on each side? Also, the plans call for six 2x3s, each 8 ft. long, per 2-ft. wide shelf. That seems overbuilt to me. Since I will be using seed flats, not gallon or larger pots, I think three 2x3s will suffice. Or maybe use hardware cloth? In this plan, the shelves help make the structure sturdier, so we need to put in at least one permanent shelf on each side.

February 11, 2015	#2
Rairdog Tomatovillian™ Join Date: May 2014 Location: Noblesville, IN Posts: 112	I would leave the shelves as is. They give you a nice sturdy place to up-pot, hold water buckets etc... Plans change. You may want to bring some bigger pots in to nurse them back to health. You could add a couple wire closet shelves above/below. Then you could remove the brace so they fold down. This gives you a place to germinate more trays with the ability to fold them down so you don't shade the wood shelves. Other options. You can put diagonal strap bracing on the corners for shear strength. It is what they use on outside corners of homes when they are just foam and vinyl siding to meet wind ratings. Simply put the polycarb right over them. If you have any snow load(not sure where in CA you are located) I would consider a collar tie 1/3 or so from the top. The ridge beam will want to sag and it will push out the sidewalls.

February 12, 2015	#4
habitat_gardener Tomatovillian™ Join Date: Apr 2008 Location: California Central Valley Posts: 2,543	Good ideas! We'll look into diagonal bracing, and other shelf options.