DIY Greenhouse on Raised Bed Easy 2hr $100 Build Video Series
For less than $100 and 2 hours I built this greenhouse for our raised bed garden using just electrical conduit and some painters plastic. Great row tunnel for winter veggies. I built this whole thing and video in less than 2 hours. A couple of short videos of the process.
Great temporary green house, I plan on moving the bed to a better location in the spring and just wanted to get something up for this winter. I broke down what my costs were buying from our local Home Depot, I already had the 2 posts and ridge beam 2×4, but I checked on the price for those as well. Our raised bed is 10′ x 20′ but I only wanted to cover half that.
These are the basic materials needed for a 10′ x 10′ existing raised bed
(14) – 10′ x 1/2″ EMT Conduit – $34.72
(2) – 4″ x 4″ x 8′ Posts – $19.40
(1) – 10′ or longer 2″ x 4″ Beam – $3.82
(5) – 1″ x 2″ x 8′ wood strips – $4.80
(20) 1/2″ 2 Hole Straps – $4.65
3 Mil or larger painters plastic 10′ x 40/50′ $18.98
Misc: Wood Screws, Duct Tape – $??? Used what I already had
Total without cost for tax/screws etc would be only $86.37
First step is setting the posts, on one end I just placed the 8′ 4×4 post on the ground against the center of the raised bed frame and used large lag screws to attach it square to the frame. For the other post I used a post hole digger and dug down a little over 1′, dropped the post in and then added dirt/rocks back while pounding the ground with a metal rod to pack it in, add a bit of water to help settle and it’s fairly stout at this point.
To add the header/ridge beam I marked off where 7′ to the top would be, then added one screw to one side, then lifted the other to the 7′ mark, check for level then added a few lag screws to each side.
Then I marked each end and spaced off 24″ marks the length of the beam and the raised bed sides. I added a dozen of the 2 hole straps on the raised bed sides where the poles would go.
Next was bending the 1/2″ EMT conduit at the right spot and angle, I found after a few quick measurements that for a 7′ height and 4′ sides on a 10′ pipe I need to mark at 48″, then used the conduit bender and bend to the 60 degree mark or close to that “it don’t have to be perfect”
After bending 12 pieces of the conduit, I had to flatten the tops, this is the longer side of the pipes. I used a large rock near the bed, but any hard surface would do, a few blows from a hammer should suffice, then just drill a 1/8″ or so hole near the end.
Next you place the poles into position, simply slide them into the conduit straps you already added, then use a wood screw to attach it to the marks on the ridge beam. It won’t be overlapping, just next to each other is close enough. After getting the poles secured on top now you need to level them and screw them in their final position.
The best way to do this is starting from one of the ends, use a hammer to flatten the pipe and either pre-drill or use long self tapping sheet metal screws as I did. Simply eyeball it straight and true, then go down the line one by one to get them all aligned, this is probably the most time consuming part.
After that it’s time for the plastic, I used a 2 roll pack of 3.5 Mil Clear painters plastic, better plastic should be bought for longer term use through a greenhouse specialty store. Use at least 3 MIl, I’ve been told that 4 Mil is regarded as 1 year plastic.
Roll out the plastic and then grab the edge that lines up with your first pole, use duct tape to tape it to the ridge beam, then pull it tight and tape the other end, then go back through and tape at every pole, then do the other side. I then went back rolled up from the middle and place a strip of Black duct tape across the seam for the entire length of the ridge.
Next is tightening and closing it all up. On the ridge I added a length of the 1×2 furring strips to sandwich the plastic between the 2×4 beam, added several wood screws to hold into place. I used the last 2 pieces of conduit on the two sides, I used duct tape again to attach the plastic to the pipe, then I rolled the pipe and plastic up pulled tight and then screwed down with 3 of the 2 hole straps to hold it. The ends of the plastic were cut/folded around pieces of 1×2 and then screwed down tight. Like wrapping a big present. The only tricky part is the door, if I were to be using this everyday for years I would frame out a proper entrance, but for now I just folded it over some wood and use a brick to hold everything tight enough.
Thanks hope you guys like this one, sort of different but none the less handy and DIY friendly!