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| The first section of the greenhouse was built in 2009. This show it in 2011 when I finished it so it runs the full length of the south side of the house. |
A lot of you have asked to see more of the construction of my greenhouse. The design had several constraints. My house was built about 1900-1919 mostly it seems of scrap. There is no crawl space or ordinary foundation. It sits on huge timbers, probably scavenged from mining operations. The center section of the house has 10 foot ceilings and was probably the original structure. It was added onto over the years with shorter shed roofed additions. None of it is straight, level or plumb. Even the roof line is wavy. The south wall of the house is only 6 ft 7 in. on the inside, so the greenhouse is not very tall.
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| Greenhouse construction |
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On the outside there was a walkway about 5 ft. wide along the house even with the floor level. South of the walk way the ground rises almost 3 feet, there was a dry stone wall here. There had been a line of trees here which I had cut down about 20 years ago because they were hollow and full of fire ants. The stumps threw up a lot of suckers. Preparatory to building the greenhouse I had to pull down the stone wall and dig out all the stumps as best I could. I then rebuilt the wall along most of it's length and this became planting bed inside the greenhouse, topped with a 2x12 board frame.
If the south side of your house is level and clear then you can build a much wider greenhouse. If the south wall of your house is taller then you can build a much taller one. If you whole area is flat then you could have beds directly in the ground without retaining walls. My dream home will be two stories with a greenhouse room the full height of the south side and about 12-14 feet wide. It will have in ground planting beds with a meandering brick and gravel pathway, a pond and stream running through it, where I can grow avocados and some citrus which I cannot grow here now.
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| 2x4 screwed to side of house, pipe fits into hole, plastic stapled to top of 2x4 |
Construction of the greenhouse is very simple. I've lost the book mark to the video where I first saw this method. As far as I know in most places this construction will not require a permit since it is made of plastic pipe, but you should check with your local authorities. All of the lumber used in mine is scavenged scrap and second and third hand, which is why some of it looks like it does. I used 2x4s screwed to the house wall with a hole drilled through them every 4 feet to take the ends of the PVC pipe. This sets the ends of the pipe right up under the eave of the house.
I set a 2x12 (you could use a 2x6, I just happened to have a 2x12) at the outer edge of the greenhouse and then played around with my tape measure to get an idea of how long to cut the pipes. Just keep in mind that you don't want the pipes to bulge upward from the house wall, they should arc gently to the ground. Once I figured out the pipe length I cut all the pipes to size.
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| The frame showing the wire mesh and the wood it's wired to. |
Because the greenhouse wall doubles as a trellis for plants in the summer I covered the bottom 5 feet with concrete reinforcing wire, so 5 feet from the end I drilled a hole through all the pipes. These holes are for small bolts to fasten a piece of 1x3 wood to. This is to give me a place to wire the reinforcing mesh to and to staple the plastic to.
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| The bottom of the PVC attached to 2x12 baseboard on inside |
The 2x12 at the outer edge of the green house has metal fasteners to accept the ends of the pipe. Then a screw is put through the wood and into the pipe to keep the pipe from sliding further down.
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| fairly simple end framing, seen here without the door in place |
On the end of the greenhouse I built a frame work from 2x4s to staple the plastic to and I built a door of 2x4s. These areas all have half lapped joints. The hardest part is to work with the curved edge which was a matter of trial and error for me. The two ends of my greenhouse are made differently. I haven't gotten around to building a second door yet. The current door has chicken wire stapled to it to help keep stray dogs and pigs out of it when there is no plastic on it. When it warms up this spring I'll build another similar door on the other end.
When covering the greenhouse with plastic I cover the bottom part by stapling to the 1x3 board, then pull it smooth and staple it to the 1x12 at the bottom. I pull the edges tight and staple them to the wooden frame at the ends; this way you have a pretty good seal at the ends. For the top of the greenhouse first I staple the length of the plastic to the 2x4s that are attached to the house. Then I use fasteners that are made to go on plastic and will accept a rope or bungee cord. I use bungee cords attached to stakes, concrete blocks or what have you to stretch and anchor the top plastic and keep it as tight as possible. With this method I can open up the whole top of the greenhouse for venting when it gets too warm in spring. Then I cover the ends and the doors. I only got one door made, so at the far end I stapled the plastic to the top part of the frame and just weighted the bottom with rocks. That way I can open it for venting if needed.
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| Sept. 2011 Greenhouse frame covered in morning glories. |
When the weather is getting pretty warm I start vine crops like cucumbers or flowers like morning glories to cover the trellis and help shade the house during the summer.
The greenhouse does freeze inside, in fact the air temp is usually almost the same as outdoors overnight. But the sun heats up the pots and soil during the day and I think that warm soil is part of why the plants grow so well in it, as well as the warmer temps during the day. During the winter on warm sunny days I open up the windows and get some of that lovely warm humid air into the house. The greenhouse also helps keep cold drying wind off the plants and I think that helps their growth too. Experiment, build your own little green shelter from what ever you have available and have fun!
