How You Can Build a Cheap DIY Canopy, Carport or Greenhouse in an Afternoon

Building an outdoor canopy can be easier and cheaper than you think.

I wish I would have put this together before I bought a carport for $2,300. I would have spent only a fraction of the cost.

Even better, it doesn't require the back-breaking work of digging footers or lifting heavy posts.
I thought I was going to try and save a little cash by building my own carport. I needed something to cover my 1976 Argosy Airstream.
I didn't think it would be that difficult. Dig a few footers, drop in some posts and I'd be done in a few days.

Well, as I was talking with the building inspector during the permit process, he suggested, due to the high winds in our area, that my footers would have to be way deeper and my posts way bigger than I was anticipating.

Forget that plan.
Instead of trying to lift 16' 8x8 treated beams in the air by myself, I went and just purchased a $2,300 fully installed carport. About 3 months after I actually bought it, they came and put it up.

Fast forward one year, my sheds are full and I need a space to store my lawn mower. I already knew the building requirements from the county and didn't want to spend another $2,000 for another pre-built shed or carport. However I've built a couple of greenhouses on my property which have very minimal building requirements and were significantly cheaper to build.

I realized this was also a great way to build a canopy structure.

Here's why:
  • Its significantly cheaper than the pre-built sheds or carports
  • This can easily be done by 1 person in less than a day
  • Possibly very little to no building code requirements
  • Greater coverage from wind driven rain than a carport
  • Better ventilation than a shed
  • If my shed ever frees up I have another greenhouse :)

So with that in mind, I needed that lawn mower cover. Here's how I did it.

Tools and Parts Needed

Parts Needed Amount Total Cost
6 Foot Pole Bender 1 $49.99
Wiggle Wire & Lock Channel 10 pack $99.99
6 Mil Greenhouse Plastic 16'x10' $60.00
½" Cross Connectors 12 $67.96
¾" Self-tapping screws 100 cnt $2.37
¾" EMT Conduit (ground posts) 3 $13.68
½" EMT Conduit (arches) 3 $8.25
1" x 4" x 8' Board 2 $13.58
Total $315.82
Tools Needed
Drill w/ Drill Bits
Hacksaw with steel cutting blades
Sledge Hammer
Ground post driver
12" bubble level
Knife and/or scissors
Pencil and Marker

Building a Greenhouse / Carport Step by Step

Ground Posts
Ground posts are typically spaced 4' feet apart. You can adjust this anywhere from 3'-6' but 4' works for most situations.

1. Cut each 10' ¾" EMT conduit pole in half.

2. Mark each 5' piece of cut conduit at 36". This is the depth that you will be hammering each ground post into the ground.

3. Lay out your ground posts 4' apart. Make sure that your layout is square. Check that each side has the same length, width and diagonal measurements.

4. Using your sledge hammer, ground post driver and a level, drive your ground posts in the ground. Keep the posts level on all sides as you work your way into the ground. Stop once you hit your 36" mark.

When all your ground posts are in we are ready to start on our arches.

The deck you see below was pre-existing. I wanted to keep my lawn mower off the ground because I'm in a flood prone area so I build my greenhouse around the deck.
Building Your Hoops
1. Measure each piece of ½ EMT conduit at 9" and put a mark. This is the spot that you will begin to bend your arches.

2. Add a second mark at 6" on the opposite end of each pole. This will be used when inserting the hoops into the ground posts. Be sure to indicate on each mark as to what it should be used for.

3. Attach your hoop bender to a sturdy table or deck.

4. Begin bending each pole starting at the 9" mark. Bend the pole every couple of inches by simply inserting the pole further into your hoop bender. Use your pole extension at the end of each bend.

Watch how the pole bender is used
Installing Arches into Ground Posts
1. Before inserting arches into ground posts slip on a cross connector. This will be used later to attach the ridge pole.
Attaching Cross Connector To Arch

2. Insert each hoop into the ground post stopping at the previously marked 6" line.

3. Once all the arches are in use a self tapping screw to secure the hoops in place.
Installing Ridge Pole
1. Slide your previously attached cross connectors to the top and center of each arch.

2. Use the ½ EMT conduit and insert into the cross connectors perpendicular to your arches.

3. Once all ridge poles are inserted into the cross connectors insure that your ridge poles are straight. Don't worry about any excess ridge pole. You will cut that off later.

4. Secure each cross connector to the ridges and bows of your hoop house using the ¾" self tapping screws. Pre-drilling is recommended.
Screwing Cross Connector To Arch Greenhouse
5. Once all cross connectors are secure, cut off the excess ridge pole and cross connectors in order to make it flush with the end hoops. You don't want anything poking out at the ends.

Installing Lock Channel and Hip-boards
At this stage you have your basic hoop frame up. Now you are ready to start putting on the finishing touches.

1. Use a 1" x 4" x 8' (really any size dimensional lumber). This will be used as your hip-board. You don't want the end of the lumber landing on a bow. Therefore cut 18" off of your first board before installing.

2. Place each piece of lumber at the height you want your plastic to go down to. Then attach each piece of lumber using conduit straps. Screw the pipe straps to the lumber around the bows. Then secure in place by running a screw through the pipe strap and into the bow.

3. Secure butt joints with a scrap piece of wood.

4. Install the lock channel on the center of your hip-boards using the ¾ self tapping screws.

5. Install lock channel around the outer hoops. Use a clamp as this will keep the channel in place as you bend it around your hoop.
Installing Greenhouse Plastic with Wiggle Wire Lock
Once all the channel is secured you are ready to install your greenhouse plastic. You want to size your plastic such that you will have a little extra for any miscalculations.

1. Simply drape your greenhouse plastic over the entire structure.
2. Begin securing the greenhouse plastic with wiggle wire lock. PVC coated wiggle wire is recommended because it is easier to install. It also is much less prone to causing any accidental punctures in your hands and the plastic. Start from the top of one of the end hoops. Evenly place the one piece of wiggle wire over the middle of the end hoop keeping the plastic tight as you secure.

3. Once you have your first piece of wiggle wire on, make any adjustments to make your plastic tight. Then begin installing the wiggle wire on the hip-board, again keeping the plastic tight as you go.

4. Once the wiggle wire lock is installed on the hip-board, secure the rest of the wiggle wire around the end hoops.

5. Once your plastic is on to your satisfaction cut off any excess.
Finished Greenhouse / Carport
I personally did this project starting at 8am and finished around noon with a few breaks mixed in. This is a great way to save money and time when you need that little extra storage area.
Want More Greenhouse Building Ideas?
Check out our other greenhouse building guides and resources.
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Build a DIY Carport Canopy in an Afternoon