An Attached Hydroponic Greenhouse
(Page updated Sunday, September 18, 2005 )
This page deals mainly with the construction history of the greenhouse. If you are more interested in our hydroponic systems and results, please click the text below...
We began eating more and more vegetables and less meat in 1997. I wanted healthy, low cholesterol and Andie was having digestive problems with meat. While I could eat hamburgers three times a day, I knew I shouldn't. This lifestyle change caused our grocery bill to shoot through the roof, and we weren't even happy with the quality of the produce at the local grocery stores.
In 1998, Andie and I visited a friend in Kissimmee, Florida and we spent a day at Disney's Epcot Center. While there, we visited an exhibit called "The Land" which focuses on agriculture; it's past, present, and future. The "ride" at The Land is a little boat trip which takes folks through some really fascinating hydroponic gardens. The food they grow there is consumed throughout the Disney Empire in their various restaurants. (I recall they actually only supply about 3% of their produce requirement in their greenhouses, though.) Here are a few shots from our "Behind the Seeds" walking tour which you can take for another $6...
For us, it was so inspirational that Andie and I decided to build our own small version. We'd then have some better control over what we were eating. We already raised our own beef and goats (for meat, milk, and cheese,) bought local mutton, and had plenty of wild game available, so the greenhouse was a natural thing for us.
It's not that you can't garden in Wyoming. You CAN, and the short-lived garden can be very productive, as my father, Donald, demonstrates below...
However, this green utopia lasts for only about three and a half months, and requires incredible amounts of water in our arid climate. Our goal is to extend the growing season to most of the year and reduce water use to a small fraction of what an outdoor garden would consume. With an earth-bermed well insulated hydroponic greenhouse we may be able to get almost ten months of living food annually, and use 10% of the water required for conventional gardening. As a fringe benefit, we'll also gain another source of solar heat for our home in the winter.
We spent a couple years reading books and planning our attack. We decided where to build it and the simple floor-plan. We sourced our glazing and other greenhouse materials. (Please visit Sundance Supply for double and triple-wall polycarbonate glazing, vent fans, trim, etc.) Then we came to a tough spot. We had to decide if we were going to connect the greenhouse to our house, or build it to stand alone. Connecting to the house would a great idea if we could pull it off, but it would involve digging out one exiting concrete wall and cutting a hole in it for a new door to the greenhouse. To keep our home earth-bermed, we'd also have to build an earth-covered tunnel to the greenhouse.
Here's shot of the location we selected. It has the perfect southern exposure. You're looking at what will become the front of the greenhouse, looking from the south-east...
The water lines and electricity had already been buried last year when I built my shop. We had to wait for the ground to thaw so we could dig out the existing house foundation to connect the greenhouse. I was really worried about the excavation of my foundation and then breaking a hole through the concrete wall for a door.
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UPDATE ON AUGUST 19TH, 2001
We're WAY behind schedule now, and I'm thinking that we'll have snow in another four weeks or so. I don't think we'll be able to have the polycarbonate on the roof before the snow flies, but it won't be the first time we've had to battle Mother Nature out here...
Here's a shot of the 406 Unimog earning her keep again, gently exposing the wall of our home. I was VERY careful at this point...
Once the area was excavated, we could build our footings forms and then pour 9.75 yards of mud into them. Once the concrete had cured and we had stripped the forms, we filled the footings with 3/4" inch 'BN' crush to make the floor...
Before we start building the Diamond Snap-Tie EPS concrete wall forms on top of our footings, we have to break out the existing concrete wall where the door to the tunnel will be located. The first step was to strip the EPS off of the wall, and I wasn't too sure how that would go. We eventually discovered that the styrofoam came off easily if chipped/scraped with a 24" crowbar...
The next step was to get a door and rent a concrete saw. We picked up a Target gasoline-powered diamond blade chainsaw made for cutting concrete. The cost of this puppy in Wyoming was $200/day + blade wear, which is checked with a micrometer before and after renting the tool. It's water cooled, and you get VERY WET running it!
Due to the amount of blade wear, we decided to use this chainsaw to make only the bottom and top horizontal cuts, and verticals at the corners. After cutting only 8 linear feet of a total required 18 feet, the blade wear came to $300! To finish the long verticals, we rented a much cheaper gasoline powered 14" concrete saw. We had success, and the Unimog backhoe lifted out the 1748 lb. chunk of wall...
When we finished cutting, Martin and I looked pretty bad... Thank God for masks!
The finished doorway, door installed, from inside our home...
Now we're building the lightweight concrete form system, Diamond Snap-Tie, purchased from Advanced Foam Plastics in Denver...
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September 4th, 2001
'Tis the morning before the big "pour" or "pump" or whatever you call it. The greenhouse and tunnel wall forms look like this...
In the following photos, we have built the greenhouse roof, which will be about 5500 lbs of concrete! The rebar is tied on one foot centers, and you can see the bracing from within the tunnel itself. The 2x4s holding up the roof will actually only have to support a total of 151 lbs each, vertically, so we THINK we're going to be okay. None of us are structural engineers, so we hope we overbuilt. In the words of a wise friend, "You'll never know if you had too much, but you'll know right away if you didn't!"
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We're FINALLY FINISHED with the concrete for this season! We're ready to move on to other things! Here are some photos from the big event...
Mike from Casper-based Mid-Mountain Concrete Pumping showed up on schedule and set up his half a million dollar Schwing 32XL pump. He was drawn to our Unimogs, and quite happy to tell us his Schwing pump was made in the Fatherland of Germany. I felt at home once I knew that, and instantly developed a sense of trust of the equipment. Everything was controlled from a radio-control transmitter. German technology or not, one screw-up on Mike's part and Martin or I would have gone tumbling off of our scaffolding...
...and a few shots of placing the concrete...
How many tools can Martin get going at once??? He LOVES concrete...
By October, we'd installed the trusses and were ready for some roofing...
After completing the tin on the back and top portion of the front roof, we screwed the glazing to the frame. It's 16mm triple-wall polycarbonate, which provides some insulation too.
The triple-wall is not clear, and it does distort the view a bit...
It's safe to say that we're really happy with the polycarbonate, even though we can't see through it. I was truly impressed when we had some very cold weather - 15ºF for a high - and a bit of snow on the roof. The interior temperature of the greenhouse was almost 100ºF at 3:00 in the afternoon, yet the snow on the roof was still there! I thought for sure it would have melted, but the heat stayed in the greenhouse! Our maximum recorded temperature so far is 131.2ºF. That's too hot, and it's just winter! I'm beginning to think there's too much glazing on the roof! What will summer bring? Wilted lettuce for sure!