Putting Up Your Greenhouse, Pt. 1

Spring has sprung, people. Print this blog now and get in your truck. You’re going shopping. A quick trip to Costco (for 1 item) and your local nursery or home-improvement center and you’ll have everything you need. You can McGuyver it if you want, but if you follow this guide precisely you’ll have a top-notch backyard greenhouse rolling in no time (one day, in fact – bring a friend).

Before we begin, you’ll need to collect the following items:

1. 1 Carport Kit (from Costco) – 10′x20′ with 11′ peak – metal tubular frame carport

From your Nursery:

1. 100′ roll of clear greenhouse plastic sheeting (6 mil thickness)
2. 100′ roll of weed fabric (huh huh) aka landscape weed blocking fabric
3. 100 Landscaping staples 6″ – 8″ long (approx)
4. 6 12″-16″ Earth Anchors (for tying off your corners)
5. 100 ft braided nylon rope (make it easy to see if you can, so you don’t trip or clothesline yourself)
6. 40′ of 2×3 12′ douglas fir stock (yes they make that now)
7. 12 – 14 4″ spring clamps (refer to photo)
8. 3 Concrete foundation blocks (refer to photo – center of greenhouse on the ground)
9. 4 16″ Oscillating fans (wall-mount)
10. 3-4 long extension cords
11. 1-3 dehumidifiers (if needed, depends on local climate)
12. 2-4 600 watt lights (we recommend Eurotwins)
13. 1 Hi-Low meter (hi-lo temp/humidity monitor)
14. 3 Surge-protector power strips
15. 10′ x 20′ of panda (black on white) visqueen (6 mil)
16. 4 8′ tarp zippers (you get those pre-made these days at your home-improvement center)
17. 10 Masonry blocks (see back of photo… holding down panda visqueen)
18. 1 big can of multi-sized zip ties
19. 3 rolls of Greenhouse Tape (6″ wide clear)
20. 1 axial outtake fan
21. 1 can of bungee cords
22. 1 extra 50′ run of nylon braided rope (for the lights)

Ok… now for the tool list… you will need:

1. Screw gun
2. Hand saw (for the wood)
3. Hammer (for the landscape staples)
4. Measuring Tape
5. Razor Knife
6. 1-2 8′ ladders (6′ will do but 8′ is safer)
7. Compass (if needed… just stand on your property and see where the sun rises – that’s east… so just figure the rest of the directions out from there, yeah you’ll have to wake up early)

Ok, now we begin…

Step 1 – Install Black Landscape Fabric

Roll out bolts of landscape fabric east to west, in 30 foot runs. Staple the first run down every 2-3 feet as you roll it out, keeping it taught. After the first run, successive runs should be overlapping each other by 12″. The material has a line layed 12″ from the edge to make this easy for you. Do this over a 30′-20′ area (approx) to ensure a spacious and clean, contaminant-free grow environment. When you are finished you should have a rectangular area of black landscape fabric 30′x20′ made of overlapping rows.

Step 2 – Construct Carport Kit

The carport frame (now a greenhouse frame) comes with good directions. It all clicks together like the family tent. Just follow the directions and you’ll have it up in no time. Make sure it is centered on your 30′x20′ area oriented longways east to west (use your compass if needed) and as level as possible. When the frame is complete, attach the included fabric on the north wall only… you won’t be using the rest… store it for later.

Step 3 – Cover it with the Clear Greenhouse Plastic

This is best done with yourself and 2 assistants when the wind is not blowing. You’ll need your Razor Knife, your greenhouse tape (the 6″ wide clear stuff), your clear plastic sheeting and a half dozen of your 4″ spring clamps (refer to photo). The goal here is to cover the greenhouse without wasting material… you do it in three pieces:

1. The first piece is going to cover the east or west side (take your pick). Go ahead and measure and cut a piece of plastic that will cover the entire end side of the carport structure, overlapping the edges by about 4-6 inches (approx.) Attach these edges with a few clamps and trim excess material, leaving a clean 4-6 inch overlap. Use short (8″ or less) pieces of the 6″ wide clear greenhouse tape in 2 foot intervals to lock down the edges of the plastic to the greenhouse frame. When you are done, the entire end face of the greenhouse should be covered in a single piece of clear plastic that is taught like a drum (as much as possible). When it’s done, run one long strip of tape around the entire edge, making a clean and sealed seam.
2. Repeat the above step on opposite end. When you are done, you’ll have both ends covered with clear plastic, taped off and sealed.
3. Cut a 10′ x 20′ run of the 6 mil panda plastic. Attach this to the interior of your north wall with the white side facing the interior of the greenhouse. Tape and seal this off using the same technique as the clear plastic end caps, tight as possible. Use your 8 masonry blocks along the interior of the north wall to pin down your panda plastic.
4. Let’s attach the clear roof. Cut a 20′ x 22′ foot run of clear greenhouse plastic (the same stuff you used on your ends). Take 2 or 3 friends and your ladders and pull this large sheet of plastic over the top of the remaining structure. Orient the plastic so that the extra (the 22′ run) plastic overlaps the east and west edges of the greenhouse. On the north edge, the plastic will overlap the carport fabric by about 1 foot. It will be trimmed and taped off to the top metal bar of the north side. The east and west edges, all along the outside of the structure, get clamped, trimmed and taped in the same manner as the end pieces (refer to step 1 again).

Step 4 – Install 2×3 framing and blocks for structural support

Layout your foundation blocks with 1 in the dead center of your greenhouse and 1 centered on each of the west and east sides. Grab your 2×3 stock and notch one end of each stud. You’ll need to measure the distance between your cement foundation blocks and the peak of your greenhouse (including the width of the tubes… you’ll notch to allow for the tube). Make sure you make your notches so the wood doesn’t poke through or rub the plastic. Drill pilot holes and attach the studs to your foundation blocks with 3″ deck screws. 3 – 4 screws will do it. We’ll put a screw in each side of the top of each stud to create anchors for zip ties to attach to (refer to photo). When you are done, you’ll have 3 foundation blocks with studs attached that reach to the roof of the carport, which now rests in the notches on the top ends of the studs.

Step 5 – Install Earth Anchors

Put your 4 earth anchors in the ground 4-6 feet from each corner, spaced diagonally from the corner. Make sure they go all the way in… 12 to 16 inches. On the north wall, we’ll add two more to the exterior of the green house, again, spaced 4-6 feet away from the edge of the greenhouse, evenly spaced from the existing corner anchors. Cut 6 approx 15 foot long pieces of rope. Take 4 of the pieces and tie one of each to each of the four exterior corners of the greenhouse, tying the other end to the corresponding earth anchor, using a trucker’s hitch knot (here’s a link). You’ll need to cut a couple of tiny holes in your plastic in order to do this, but it’s worth it when the wind picks up. Make sure these tie offs are tight. Cover the holes you made with extra greenhouse tape.

Step 6 – Zipper Doors

Zipper Doors

The zippers will come with instructions for installation, and you can refer to our photos. You’ll tape the zippers up, evenly spaced on each of the east and west sides. You’ll be putting 2 on each end. After cutting the strip for the tape you’ll want to staple it using your hand stapler about every 6 inches. Refer to the photos.

Step 7 – Install Fans

Outtake Fan

Mount your fans on the east and west studs facing the interior of the green house, about 7′ up. Refer to the manufacturer instructions and our photos for mounting the fans. It’s really easy. Install the 10″ Axial outtake fan. Cut a 9 inch “x” in the material that the outtake fan will be inserted in and taped to. Put a couple of eye-bolts in a piece of wood screwed to the neighboring stud. The weight of the fan is then supported by a bungie cord hanging from the eye-bolts. Refer to the photo for exact installation details.

Step 8 – Install Dehumidifier and Lights

Place the 1 to 3 dehumidifiers evenly throughout the greenhouse according to humidity. Attach 1 bungie cord to each light by hooking the ends of the bungie cord to the hooks provided on the light shell. Tie an 8′ piece of rope around the center of the bungie cord and mount it to the top of tube. Evenly space your lights along peak of the greenhouse. Put your ballasts and dehumidifiers above ground, using masonry blocks to keep them dry.

Step 9 – Running power to your greenhouse

Figure out how much power is going to be needed. Make sure you have plenty of overhead on your power circuit. Try to use 120v light ballasts if getting 240v to your greenhouse is going to be an issue. It is a good idea to run extension cords from a couple of different circuits so you aren’t heating up too much. If you have any questions about your power situation we highly recommend consulting a qualified electrician. Get some extension cords running to your spot, then, using your power strips, distribute your power keeping the lights and the fans on a seperate circuits if possible. Layout your power strips and cords according to your preference. Tie your cords off to studs and tubs with zip ties and keep your edges clean and organized.

Step 10 – Wrap it up and Clean it Up

Clean up your scrap, test your lights and fans, and troubleshoot any problems. Let it all run for a few hours without anything in it and determine that your power situation is stable and reliable. Once you are done, sweep it out nice and clean, wipe down any plastic that got dirty in the process, and get ready to move in your ladies!

Posted Tuesday, May 6th, 2008 | In Growing, Guerilla Speeks.
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