Building a Greenhouse, What's Required?

That might be some thing that is covered under local building codes.

But here I've seen them erected on concrete pads, crush and run some of those with asphault walkways, on asphault and bare ground. Most of these were at comercial growers for the florist industry. Some at nurseries for the public. A few at some residences on wood decks.

Your client if building a green house at his residence would want it to compliment his home. if attached to the house I would think it would come under the definition as an addition and all building codes would apply.

gOOD afternoon ozzb, thx for your post.

I think the local building dept. sent him to me.

You raise some interesting points. He gave me some rough sketches, which do not show a floor. They do show, however, that it is 27' from the house. He plans on using 2x4 framing and engineered trusses, on top of a 8x12 (vertical) footing with 2-#4 bars.

The local residential wind load is 90 mph. Does a greenhouse have to withstand this load? I was planning on using some Simpson strap to accomplish this.

The IRC calls for a minimum width footing of 12" horizontal. Does that apply to a greenhouse? But since the load is so light, I'm investigating whether his 8" width is ok.

The wind does not differentiate what kind of structure it blows on. Whatever the building code says, you should design the structure for full wind pressure.

So far as the footing is concerned, you won't save any significant amount of money by cutting the width of footing from 12" to 8", so why do it?

That was the owner's idea, to make it 8" wide and 12" hi, with the upper 4" above ground; to make it as cheap as possible.

convince him that the extra few $$ for a 12" X 12" footing will equate to better service life for his greenhouse.

the exrta mass involved wil make it less likely to move due to frost heave and other soil movement.

gOod morning, Charllie_r, that is a good point I hadn't thot of before.

Fir a few years I collected the glass from sliding doors people would replace I now have a 30 ft by 60 ft greenhouse framed of 4x4's and glass wall held in place with 2x4's. I don't have 90 mile and hour winds though. Gust of 50 mph winds at most. The fames is on a 2 row deep 8 in block foundation.

Good morning dadw5boys, thx for the post. I take it your foundation is 1-8"CMU wide and 2 tall? I imagine most private greenhouses are only used during the winter, as summers would be too hot without a fan?

Depends on your location - often natural ventilation is sufficient.

Oh I have fans on both ends. I also have 16 -55 gal blue plastic barrels buried in the ground and a solar pump which moves the water during the hottest part of the day and stores the heated water in the barrels to be leached back out at night. T he fans at mounted just above the doors on either end. I did have to have a 10 peices of custom cut glass to finish the project. We start in mid March and raise tomatoes until december then we only have fresh greens. Of course we have green in row crops too but keep some in the greenhouse. Once in a while a herd of deer will form a raiding party and eat all the greens.

Saw a bear paw print on the side of the green house on morning so I stop everyone from bringing food there and removed the trash can back to the barn. A bear pushed in my neighbors block wall on one side of her chicken coop and got all of them. Contact a local flass company and maybe they will save the old sliding doors for you like they did for me. They were the company that installed new windows in my house so I guilted them into it.

Good morning, dadw5boys, there's nothing like fresh tomatoes. I envy you. I have a couple 30-gal plastic barrels I'm going to give to a friend, who's going to catch rainwater with them. It's obvious you've been very industrious. Around here, it gets so hot, tomatoes have a hard time just out in the open. In a greenhouse, I bet they wouldn't make it a week. Here, at 5,000 ft, they use greenhouses to grow stuff during the winter. Sometimes a javalina will wander in and eat flowers and plants. I don't have a place to build a greenhouse, and my broken back will not let me do physical things.

Yeah my back too after the 9th operation I told the doctors no more.

I collected the glass for my green house and took some time but I only had to hire a couple of gut for 3 days to get it done.

I had been laying the thing out for about 2 years before I even leveled the ground.