DIY PVC pipe and builders plastic hoop style greenhouse

[moolie]

Got to thinking about Joel's request to post DIY instructions here in addition to my journal, and realized that our greenhouse project might be helpful to others as well

September 2011 we had three 2x8' raised garden beds that we wanted more frost protection for than just row covers, so we purchased some PVC pipe and built our first hoop house. We learned a few things from our ad hoc attempt at greenhouse building and re-built the structure this past May. Here's the story in pictures...

Well, we got the hoops for the hoop house up this evening and now we just need to secure the plastic.

We have clear vapour barrier plastic sheeting that we'll secure with half-pipe type clamps. Trying to decide how to make "doors" for the aisles between the raised beds, probably with peel-n-stick zippers.

We're not sure if the plastic will hold up when it snows, but it's easy to take down so if it seems to be sagging we'll take it down and store the parts in the garage. We're hoping that our slope is steep enough for the snow to slide off, but we are spanning 3 2x8" raised beds with 30" pathways between, so a total width of 132" with 20' hoops.

Our hoop house is built with 10' sections of 3/4" pvc pipe: there are 4 hoops and each is made out of two 10' sections of pipe joined in the middle with either a 4-way connector (middle two hoops) or 3-way connection (end two hoops). We cut a length of pvc pipe into pieces to make the ridge pole that is attached to each hoop with the connectors. The ends of the hoops are slid over 30" lengths of copper pipe pounded into the ground with 12" left above ground. The plastic will be attached to the front and back first, then the top, with half-pipe clamps (sold with the pvc connectors--we got ours at Lee Valley Tools ) and also battened along the bottom edges to the sides and front/back of the raised beds with strips of wood.

Photo from the Lee Valley Tools link posted above to show how the connectors and clamps work:

We had spare copper pipe hanging around the garage from something else, so that got cut into 30" lengths and pounded into the ground to anchor the ends of each hoop. Instructions we have found for building something like this suggested rebar or other metal pipe for the anchors, so use what you have handy

The 9 10' sections of 3/4" pvc pipe cost $7.98 each from Rona (like Home Hardware or Lowes) so a total of $71.82 plus tax.

The 4 pvc connectors total cost was $9 plus tax.

The 100' roll of 10' wide vapour barrier cost $56 plus tax. Plenty left over for another whole greenhouse, same size.

So total before tax was $136.82 plus tax (which for us in AB is 5% GST).

(edited: forgot the zipper cost, those were $9.95 each, so add another $20 to my total above.)

mid November 2011, we had taken the plastic off when winds lifted the structure and actually pulled the PVC pipes off the copper pipes pounded into the ground at the front corner, but then we put the top part back on after the storm--never got the front and back put back on before it snowed:

May 2012

week of May 1st, took plastic down for easier removal/taking apart old beds to build the 4'x4' and 4'x8' beds shown in the other photos in preparation to build new greenhouse but will instead be reinforcing hoophouse and building 2 new 2'x8' beds for interior of hoophouse. Hubs is reinforcing our hoophouse for the new season so we can grow our bell peppers and some of our tomatoes in there. We had picked up some freebie windows as listed on freecycle last fall, but funds and time just don't allow at the moment for us to build them into a proper greenhouse just yet. Hopefully over the summer or into the fall we can get that built, but not at the moment.

So today dawned bright and sunny, and we got tons of work done today on the new and improved hoop house! We just came inside after a busy day (it's almost 7:30pm) and tomorrow we will hopefully get the plastic on and build/attach the doors--I want Dutch doors front and back so I can open the tops for ventilation

Our original 11'x8' hoop house was constructed over top of 3 existing 2'x8' raised beds last fall, to extend our season. The new and improved one is being constructed specifically as a green house over two 2'x8' raised beds with just a center aisle (the two aisles didn't work so well), so we've beefed up the structure by adding a wooden base and more hoops--old one had 4, new one has 6 hoops.


We built a 10'x8' base out of 2x4s, drilled 1 1/8" holes in the sides for the hoops, and pounded the 2" copper pipe anchors a foot into the ground, then popped in our 10' sections of PVC pipe.

We had to make a trip to Rona AND Lowes AND 2 Home Depots to get more PVC pipes for the additional hoops, as one store had the PVC pipe (Home Depot), one had the cross fittings(a different Home Depot), and Lowes and Rona had nothing.

Door frames up!

Everything plumb and square and ready for plastic and doors!

Hi Moolie!!!

Everything looks to be growing well!! I love the new hoop house. I tried something similar but had issues fitting the plasic. How are you going to do yours?

g

Thanks Gina!

We actually put the plastic on yesterday! We first attached the front and back sections, then the long section over the top. We just need to staple along the bottom edge and trim the excess.

We used the same vapour barrier plastic from Rona (like Lowes or Home Depot) that we used last year and attached it with PVC "U-Clamps" we got from Lee Valley that look like the lower picture here:

We didn't have time last night, and today it's been raining on and off (I darted outside during a sunny moment to take these photos with my mobile phone), but we plan to put in a door that we picked up at the Habitat for Humanity Re-Store:

(please excuse the messy garage)

Hubs had originally planned to just make wooden frames and cover them with the vapour barrier plastic, but wasn't sure how they would hold up, so we went shopping last night. We will get another door for the back when we can find something similar--the other doors they had with similar windows were all too wide.

Hubs just came in after putting up the hoop house door:

We bought it used from the Habitat for Humanity Re-Store for $40. It's been waiting in the garage since we bought it because it's been raining pretty much every day since then. Today was sunny and warm but the forecast is for rain for the rest of the week/weekend, so we had to do it today if we are going to plant anything in there this weekend.
.

And a late July 2012 view of our back yard gardens--the view is a bit distorted by my 16mm wide angle lens, so for an idea of scale: the deck is 16x16, the shed is 8x10, the greenhouse is 8x10, the square garden beds in the center of the yard are 4x4, and the long garden beds just visible to the left are 4x8.

 

[Dawn419]

I'm so glad that you posted this, moolie!

I just pulled the remnants of our first attempted pvc cold frame out of the garden yesterday and thought the whole time about how we could rebuild it to make it last longer/work better and you just took out a ton of guess work for me!

I was tempted to call it a failed experiment, but, we had fresh salad greens all that winter (2009-2010) and it was our worst winter since moving out here in the fall of 2009, so there was no "fail" involved!

 

[moolie]

Hey Dawn! Glad the info is useful

The most important things we learned were to put in more hoops than you think you need (we have 6 for 8' of sidewall), to really secure the entire structure to the ground (over 100km/hour winds the other day didn't budge it, and I didn't get outside in time before the storm hit to close the door so that was with the door open), and to make sure there is adequate ventilation (it's doing ok with just one door, but I'd like to add at least a window at the other end or another door for cross breeze).

 

[hoosier]

Thanks for taking the time to share this. This looks like something we could manage.

 

[Dawn419]

Hi moolie!

Lack of hoopage was definately the downfall in our first attempt. It was roughly a 5' x 10' and we had three hoops...the 2 ends and one in the center.

We'd have probably built it a bit sturdier but were told that the winters here were just like the ones we had in TN. Boy, did that winter prove them wrong!

 

[moolie]

Yeah, we got some saggage in the snow with only 4 pipes over 8 feet (although both hubs and I think our biggest issue was the wind picking up the corner of the structure, which we have now remedied with the heavy sturdy base) so now we have high hopes for this coming winter on both scores

We don't get a lot of snow at any one time, our warm Chinook winds that blow down from the Rockies every few weeks throughout the winter months tend to melt everything and then we start over again each time it snows. BUT even though this past winter was normal-to-mild, the previous two winters were ridiculous, with winter 2011 being the worst many people had seen in their lifetimes--we had over 2 feet of snow on the ground for over 100 continuous days, which just never happens here. And both 2011 and 2010 were much colder than usual--well, we had the cold for much longer stretches than usual due to way fewer Chinooks.

So we want to be ready for anything.