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50 Dollar Greenhouse

Building the Greenhouse Doors >>
My $50 Greenhouse

My $50 Greenhouse

Materials list

Construction Steps

Hind Sight - What I would do differently

The planning is over and construction on my hoop house greenhouse has begun. I’ve rounded up all of the materials and it looks like I’m going to end up with about $50 in a 165 square ft. green house. Granted I already had most of the materials because I’m an incorrigible pack rat, but even if I had bought everything new just for this project It would still only come to about $120 $150 - less than a dollar per square ft. Due to the fact that we are in the midst of a global economic meltdown, and the future is a bit uncertain keeping the cost of this project as low as possible is an important consideration.

After some research I’ve decided to build the structure of the hoop house out of 20 ft. joints of three quarter inch PVC plumbing pipe. Some similar greenhouse designs that I’ve run across use 10 ft joints of pipe and then fasten everything together with pipe fittings, but I’m saving quite a bit of cash with the long joints of pipe and by not using any fittings - also overall simplicity is improved. There is one thing though, you can carry 10 ft joints of pipe in the mini van, but hauling 20′ pipe requires a truck and preferably a ladder rack. However, you could just cut them in half right at the home improvement store and then put them back together when you get home with the coupling that is built into one end of the 20′ long pipe joints - 10′ pipe joints don’t have the built in couplers - just go to the home improvement store prepared with a saw or pipe cutter.

My hoop house green house is going to be 11 feet wide and 15 feet long, and will be about seven and a half feet tall in the center. You could make one of these as long or as short as you want, but using this design the width needs to be between 10-12 feet. 11 feet wide just happpened to work out with the layout of my garden which has 3 foot wide beds with 5 ft paths between (the wide paths are so that I can keep it tidy with my riding lawn mower) so eleven feet covers two beds and the path between them. This width also makes the sides go fairly straight up from the ground for the first few feet - I’ve noticed that in some hoop house designs the outer edges are almost unusable because of the slope of the greenhouse sides.

How to Build the $50 Hoop House

I decided to begin the construction by building the end walls first - even though it would be more fun to throw up the main structure in just an hour or so and make a big showing of progress, I think that in the long run it will be quicker and easier to build the end frames first on my garage floor.
I temporarily attached a joint of pipe to a piece of 1x4 to establish the outline.

I temporarily attached a joint of pipe to a piece of 1x4 to establish the outline.
Pre-drill the pipe and use one screw so that the pipe can swivel to whatever angle it naturally aligns to.

Pre-drill the pipe and use one screw so that the pipe can swivel to whatever angle it naturally aligns to. For now just let the wood "run wild"

I used pressure treated lumber for a lot of my end frames even though I usually try to avoid treated wood in the garden. In this case I think it’s called for or else the greenhouse probably wouldn’t last more than 2-3 years without rebuilding the frame. In any event I’ll try to keep it off of the soil as much as possible.
Build the rest of the frame to accomodate the door size that you want to use.

Build the rest of the frame to accommodate the door size that you want to use. My door will be 5 feet wide, but in most cases 3' wide would be adequate.

Leave the piece that runs across the bottom of the door in place for now. Once everything is set in place it will be easy to cut out with a hand saw.
I used a bit of weather resistand glue at all of the joints to help make it all more rigid.

I used a bit of weather resistand glue at all of the joints to help make it all more rigid. Notice the wood recycled from concrete form lumber.
Mark the final outline once the wooden parts are assembled.

Mark the final outline once the wooden parts are assembled. Watch out for that screw when you saw to the line!
Now just trim to the line - I used a reciprocating/sabre saw, but you could also use a hand saw or circular saw if its all you have. Just make a straight cut in about the right place.

Now just trim to the line - I used a reciprocating/sabre saw, but you could also use a hand saw or circular saw if it's all you have. Just make a straight cut in about the right place.
Now re-attach the pipe to the outside of the frame. I used screws and wire ties because Im a belt *and* suspenders kind of guy.

Now re-attach the pipe to the outside of the frame. I used screws and wire ties because I'm a belt *and* suspenders kind of guy.

The end wall frames ended up being reasonably light and very rigid. BTW, you might notice that the second one is different (simpler) from the first because this is a learn-as-I go process. Both of them work fine though.
back side of the green house end frame

back side of the green house end frame
and the front side...

and the front side...

This is the front side because it is all on one plane so that the plastic skin will lay flat on it. The back side has reinforcement gussets that stick out.

And Now for the Plastic

The plastic sheeting that I’m using is plain old non-UV stabilized 6 mil “clear” plastic sheeting from the lumber yard. There is exactly one reason that I am using this particular variety instead of special greenhouse plastic - it’s what I have. I cut a 22′ piece off of a 100′ x 20′ roll that I already had (I’m a contractor) which was about $90 for the roll - so in essence I used about $22 worth of plastic sheeting after you apply the 10% TN sales tax. Had I ordered real green house plastic from littlegreenhouse.com a similar sized piece of 6 mil plastic would have been about $71 with shipping. The real deal would no doubt last much longer than the “visqueen” that I’m using, and also probably has better thermal and light transmittance. If all goes well maybe I’ll get some of that next year. Also, It’s hard to buy large pieces of heavy duty plastic like this without buying a whole roll, so unless you know a contractor or Mom and Pop hardware store that will cut you a piece you might really be better off ordering some of the good stuff. On the other hand a big roll of plastic sheet is one of those things that comes in awfully handy some times.
I just rolled the plastic out on the frame...

I just rolled the plastic out on the frame... Notice the falling leaves - I'm racing against fall weather with this project.
and cut it off nice and clean with a sharp utility knife.

and cut it off nice and clean with a sharp utility knife. A scrap of wood to cut over and a sharp knife make this much easier.
after stapling the plastic to the front, flip it over and fold it over and staple it to the back. Just fold the excess together as you go.

after stapling the plastic to the front, flip the frame over and fold over the plastic and staple it to the back. Just fold the excess together as you go. Fold in the direction that will be down so that condensation won't collect under the folds.
then trim off the excess.

then trim off the excess. Be careful not to make a miss-cut!
Cut the plastic out of the door opening - leave enough to fold double before stapling it to the frame.

Cut the plastic out of the door opening - leave enough to fold double before stapling it to the frame. Notice the cuts back to the corners of at the top.
Thusly

Thusly
Mark out the locations of the door sides on the ground, and drive fence posts or pieces of rebar.

Mark out the locations of the door sides on the ground, and drive fence posts or long pieces of rebar at the sides of the door frame.

If you have much wind I would recommend using steel fence posts or rebar that is at least 5/8″ diameter in these spots. My fence posts don’t match because they’re left overs from previous projects - remember, I’m on a tight budget!
Check the fence posts for plumb and bend them a little if they need straightening.

Check the fence posts for plumb and bend them a little if they need straightening.
Tie the hoop house end frames to the fence posts with wire ties, wire or rope.

Tie the hoop house end frames to the fence posts with wire ties, wire or rope.

The humongous wire ties made this really quick easy and strong, but If I didn’t already have them I would just use “baling” wire, and it would work as well.
Once the end frames are in place pull a string to line up the stakes for the ribs.

Once the end frames are in place pull a string to line up the stakes for the ribs.
Drive rebar pins every 3 feet to secure the intermediate ribs...

Drive rebar pins every 3 feet to secure the intermediate ribs...
At this point it takes about 2 minutes to install the pvc pipes for the intermediate ribs.

At this point it takes about 2 minutes to install the pvc pipes for the intermediate ribs.

As you can see it’s getting dark, and I’ll have to finish this later. Total time invested so far is about 2 1/2 hours. I believe that taking the greenhouse down next summer, and re-assembling it in the fall will probably only take an hour or so, but I guess I’ll see about that.

Since the site location where I’m building my greenhouse isn’t all that level I had to raise up one side of the end frames with some 2×6s that I ripped to fit - later I cut the tail off where it sticks out toward the fence. Also notice that this means that the PVC pipes that are the intermediate ribs are too low where they hit the ground…

So I extended them with some scraps of PVC conduit that I had - I never throw anything away. BTW, the gray PVC conduit is sunlight resistant unlike the white - although somewhat more expensive and is less expensive! If you want to do a really good job you could use it instead. You should probably use the gray conduit instead of the white pipe that I used. You could even opt for schedule 80 conduit which is much thicker if you wanted to go whole hog, or if you needed to make a structure that is sturdier, more permanent or wider.

I strung it all together with 1×2s that I ripped out of some slightly used 2×4 studs…

I used a few wire ties to get everything located, and then drove a 1 1/4″ drywall screw at each joint to secure it. As you can see by the lay out marks, I first measured and marked all of the locations so that it would go together reasonably straight.

If you look really close in this picture you will see the wires that serve as X bracing on the sides.

I used a doubled wire that I attached at the top and bottom of the ends using a washer and a screw.

I then used some scraps of wood to twist the double wires together and tighten them up like a rubber band airplane. You just want them to be snug so don’t go nuts tightening them up. These wires really go a long way to make the whole structure more rigid and sturdy.

Now for the plastic covering - measure and cut your piece of plastic - you want a little extra in all directions - the piece that I used is 20′ x 22′.

My greenhouse is 15′ feet long so I cut a 2×2 x 15′ - Here I’m positioning it in the center of one of the 20′ edges of the plastic - leaving 2 1/2 of plastic past the ends of the 2×2. Staple it together just to hold it in position.

Now roll the 2×2 under one complete turn so that the edge you stapled is facing up under the top layer of plastic sheet.

Now screw a 1×2 on to secure the plastic. By wrapping the plastic around the 2×2, and then sandwiching 2 layers between the 2 pieces of wood you make a very secure connection, and also add some weight to the bottom edges to help keep them from billowing up in the wind. Do the same thing to the opposite edge, and then roll it all up and get someone to help you carry it to the hoop house and unroll it across the top…

Thusly. Now you almost have a greenhouse.

Roll under the edges on the ends and staple them securely, and other than the doors the structure of your greenhouse is finished. Total time at this point - about 6 hours. Everything is a bigger job than it seems like it’s going to be. Rake soil or mulch up to the gaps at the bottom to keep out drafts and (larger) critters. Cats in particular are likely to be attracted to such a nice sheltered spot with a bed full of soft loose dirt to dig in so pay attention to the details. Rocks, bricks or concrete stepping stones or blocks placed on top of the soil/mulch around the outside edges are probably a good idea.

Before I even started on the hoop house I tilled copious amounts of compost into the beds where the greenhouse was going to end up. So, even though I probably won’t get a chance to put up the doors until next weekend (which is Halloween), I’m all ready to plant some lettuce and spinach for (hopefully) some fresh mid winter greens. One of my goals in building this project is to have something fresh coming out of the garden or greenhouse all year long. That might be a little optimistic, but I’m going to give it a shot.

Addendum:

Complete Materials list for the “$50 Greenhouse” - As Built

Each Qty Total
$4. 23 6 $25.38 20′ x 3/4″ PVC schedule 40 plumbing pipe
$6.70 6 $40.20 1×6x8′ pt - ripped into 1×3s
$4.99 4 $19.96 8′ steel “T” fence post
$2.18 3 $6.54 2×4 stud - rip into 1×2s
$3.97 2 $7.94 1×4x12′ pt
$5.73 1 $5.73 2×4x16′ rip into 2×2s
$7.91 1 $7.91 20′x1/2″ rebar - cut into 18′ lengths
$4.88 .75 $3.66 8″ nylon wire ties - 100
$5.47 .5 $2.74 1 1/4″ x 1lb drywall screws
$6.97 .3 $2.09 16 guage galvanized utility wire - 200′ - for X braces
$2.97 .25 $0.74 3/8″ t-50 staples - 1000
$79.00 .22 $17.38 20′ x 100′ x 6 mil clear plastic
Scraps of plywood for reinforcements - scrounged
$140.27 Total

OK, that’s a bit more than I estimated because I didn’t count all of the minor bits that I just take for granted because I buy them in bulk and keep them on hand. These prices are what you would pay if you just bought the quantities that you need for this project. Drywall screws for example are only about a third as much when you buy a 25 lb box like I do being a contractor. However, you can shave most of the 20 dollar overage by using 5/8 rebar instead of fence posts, and gray UV resistant PVC conduit which is actually less expensive than the non resistant white plumbing pipe that I used - you can also do without wire ties, and use scraps of wire instead, etc. I already had everything on hand except for the PVC pipe and a couple of pieces of 1×6 lumber. However, surely almost anyone can get some of this stuff for cheap or free if they put some time and effort into it - so shop around and use your imagination to find what will work best for you.

Admittedly it might be hard for most people to build this for just $50 out of pocket, but then again a serious scrounger can probably do it for even less.

Hind Sight - What I would do Differently

1. Use UV resistant gray PVC Conduit instead of white plumbing pipe - it should last longer and is actually less expensive
2. Use UV resistant greenhouse plastic instead of “visqueen” construction plastic - It’s a good bit more expensive, but I’m so pleased with how the project turned out so far that I’m pretty sure the investment in durability would be worth while. However, if the extra expense meant putting off the project I would go ahead and use the cheap plastic because 1) The plastic will have to be replaced sooner or later anyway and the difference in cost seems proportional to the difference in life span 2) It wouldn’t be worth putting off having a perfectly usable greenhouse.
3. I should have painted the PVC pipes with latex paint before applying the plastic sheeting - apparently this makes the plastic last longer, and maybe makes the frame pipes more resistant to UV.
4. Site Selection - As you can see in the pictures my garden is in a clearing in the woods and the truth is it doesn’t get as much sun as I would like for it to - however I can still grow a nice garden - it just doesn’t yield as much as it might. I can’t really do very much about this, but you should keep in mind that you want as much sun as possible as well as a sheltered well drained spot that is as close to the kitchen as possible so that it isn’t too much trouble to trot out and get a bowl of fresh lettuce for supper. All that being said - do the best you can with the spot you have, and you might be surprised with the results you can get with a little effort.

BTW, Stumblers - Thanks for all the thumbs up. Feel free to hotlink the images or scrape the text as long as you leave the links intact!

Other homebuilt greenhouses:

* A great wood framed greenhouse design - great construction details.
* Another $50 greenhouse - Seriously.
* A PVC 1/2 hoop house built onto the side of a home for $58 - should be very efficient.

The Greenhouse doors are built now and my small hoop house is complete.

Update - Dec. 10, 2008 - we had 2″ of rain and 30 mile per hour winds last night and so far so good - no damage to the greenhouse.

Building the Greenhouse Doors >>

* Related PostsHoop House - Greenhouse
* Building the Greenhouse Doors
* Starting Pansies from Seed
* Grow All Winter In a Cold Frame Made From Recycled Materials
* Gardening on the Cheap

Written by David LaFerney in: Green House / Cold Frames | Tags: garden, gardening, Green House / Cold Frames, greenhouse, greenhouse designs, hoop house, organic gardening

Contact Information

The Door Garden is a project that my sister Donna Wheatley (Meridian, Mississippi) and I (Cookeville, TN) hatched while our families were on vacation together in 2007. We’re both interested in gardening and growing things but in different aspects. Donna is especially interested in ornamentals and landscape design while I am more into sustainable organic food production. We both like to try out different ideas and techniques, and we hope that our readers will be interested and entertained by what we learn. Thanks for visiting. You can contact me directly at david dot laferney at gmail.

David LaFerney