New Greenhouse: Lessons, Budget, Design

March 31, 2014

It’s a sad truth:  greenhouses don’t last forever.  At least not the common poly-and-PVC DIY kind.  Our plastic was tearing and I could stand the blaring red Tuck-Tape no longer, so it was time to tear down and build back up.

My dream: to be able to enter and exit the greenhouse without bumping my forehead, spin around inside it with my arms spread wide, and have it be roomy enough to grow some blue-ribbon tomatoes and peppers.  That last one will likely remain a dream, but the other two were accomplished!

I enlisted the expertise of Jesse Brown from Victoria Aquaponics to help me with the design and installation, as well as the muscles of a couple dear volunteers to help with the demolition of the old greenhouse.

Vital stats:

  • Dimenions: 12’x12’x8′
  • Length of hoops: 22ft
  • Dimensions of plastic: 2 pieces at 12’x14′, 1 piece at 12’x16′
  • Time to raise the frame and put roof plastic on: 7 hours (1 day)
  • Time to wrap and tighten plastic on ends and roof: 4 hours
  • Cost of materials: ~$600 (I bought everything new, and we get a discount at Castle Building, so true cost may be slightly higher.  This could definitely be off-set by scavenging for used/free materials.  Try UsedVictoria or Craigslist).

Here we go! (click the photos to enlarge)

Ready to retire..
Ready to retire..
Louis Greenhouse
Rock star volunteer Louis taking a break from pulling the dreaded rebar out of the ground.
Greenhouse door down 1
Greenhouse door down 4
Greenhouse down1
Greenhouse down…
Got ‘er level!
New hoops raise the height of the new greenhouse to 8 ft…and save me from so much forehead-banging.
Rebar pounded 2′ into the ground, secured to base with metal strapping. PVC slides over rebar, secured to frame with clamp and screws. Hoops were placed every 3 feet.
angle cut Jess
Jess takes care of the angle cuts for the end frames, only 4 total for the whole greenhouse!
plastic on
Ends framed, plastic on.
thumb's up
My thoughts at the end of the day.
Plastic-wrapping the ends…
Definitely a two-person job!
Definitely a two-person job!
Finished greenhouse
Side-support hoops a la Mason Street City Farm!
corner secure
Side-support hoops (on the left) are secured in the corners with metal strapping and screws…
zap straps
…and secured to each cross-hoop with an X of zap straps.
The door. Note placement of hinges!
Aaaand fin!  It’s raining…but we’re DRY! What the greenhouse is truly meant for: sipping coffees and looking good.

What I learned:

Ask for help!  Wrapping the greenhouse in plastic and then tightening is something that can be done by one person, but you will never want to build another greenhouse again and your plastic will likely end up with holes/mis-cuts in it (either from you making a mistake or literally just loosing it and taking the scissors to it to release some frustration).  I could not have done this project as fast or with as much enjoyment without the help of Jess of Victoria Aquaponics, the always friendly and knowledgeable folks at Cook St. Castle and Louis, one of our long-standing (long-suffering?) volunteers.

Spray-paint the PVC before installing.  The PVC and the plastic react with each other in sunlight, making the plastic break down and split over time (note where the red Tuck-Tape is in the first picture). Having a protective layer between the plastic and the PVC extends the life of you plastic.

PVC stands for polyvinyl chloride.”Poly” refers to the polyethylene plastic you will cover your greenhouse in.  There are lots of different kinds of poly.  You want 6mm with a UV barrier, possibly a condensation barrier too.  Integrity Sales stocks this and sells it by the square foot.  BW Greenhouse in Abbostford has the UV + condensation barrier kind.

Always check that things are level, measure twice and take your time!

Open source

I wanted this to be a free and easily accessible project.  So: a rough budget for this greenhouse is below, you can click on the photos above to enlarge them and get a better view of how it’s put together and you can call the Centre if anything is unclear.  May the future bring you many, many completely ripe tomatoes! 

Posted in Blog, Featured

One thought on “New Greenhouse: Lessons, Budget, Design

Leave a Reply