PVC Greenhouse: Wrapping the greenhouse

So now you have the frame complete (except for the door which will come later). You are ready to wrap you greenhouse.

The supplies I used were:
- 1 - 20' x 25' - 4 mil plastic sheeting (note: this year I'm going for 5 mil)
- about 50 snapclamps (various sizes)

Snap clamps, pictured below, are these need litte device that are used to clamp tarp and plastic sheeting to pvc pipe.













So, before you unroll your huge plastic sheet makes sure you either have a non-windy day or a buddy. The thing will blow around and you'll never get that big thing onto you frame.

Open up your tarp. Take one edge and insert it under the greenhouse to the half point. Now take the tarp and roll it up one side of the green house, over the top and back down the other side.Tuck the edge under the greenhouse. Have the two edges meet in the middle under the greenhouse.


You now have the plastic sheeting forming a big tube around the greenhouse with plenty of slack on both ends. You can now attaching the plastic sheet to the rib poles using the correct sized snapclamps. You can place about 3 per rib. Start by the door, completing and entire pole on ight then left, and work your way back. Two important tips: First, if the tarp is too tight applying the snapclamps can tear the plastic. The tarp has to be loose enough that is can wrap around each rib then add the clamp. The second is that winter winds will put stress on you sheets where they meet the clamps. Consider adding a small patch of duct tape to the sheeting where it meets the clamp. (I have never done this but will for this winter)

Now, you have to wrap the end of the trap around the frame. This takes a bit of creativity but is like wrapping a giant birthday present where the tarp is wrapping paper. Standing outside the greenhouse, I took all the excess tarp from the right side and wrapped it around the rear until it met the the leftside. Now bring the left excess over to the right. make sure the trap is alway laying in such a way that rain will run off, and not into, the folds of your tarp. Secure the sheeting strategically with more snap clamps. Tuck the extra at the bottom under the greenhouse and also secure with snapclamps.

The method above gives you overlapping layers of plastic sheeting. Not as pretty as if you cut the sheet to fit perefctly but it lasted all winter and was quite air tight.

Take your time and you'll end up with something like this:



(Nice picture...right? truth is, that sheet is wrapped a bit to tight and did not leave enough slack around the snap clamps. I has plenty of tearing that year and learned to leave the sheeting a little more baggy)

Tags: greenhouse, pvc, roof deck

PVC Greenhouse: The Ribs

Once the square support and the back wall are assembled, it become pretty obvious how to attach the ribs. After all, we've done the work of aligning the 45 degree connectors on the ridge pole and the T - connectors on the base.

Grab a ladder and start adding ribs between the ridge pole and the base. If you plan to take your greenhouse down in the summer (or ever!) do not glue the ribs. Friction fit only at top and bottom. When you are done it should look like this. (that long horizontal bend intentional at this point)

Since attaching the ribs is so easy this step is more about tips and tricks. First, without some kind of fastener the ribs would pop out at the first big wind of the season. To attach at the top and base I chose plastic wire ties. I drilled a small hole through the 45 degree fastener and the rib pole. Be sure there is enough overlap that the hole can go cleanly through both. Once you have the hole slip the wire tie through and secure. See image below.

Repeat top and bottom for all poles.

You should also attach the first and last pairs to the square supports be just wrapping them together with more ties (no drilling needed).

Remember that horizontal droop we saw? Well you should also attach the rib p[airs to the long horizontal bars...Again with wire ties(again no drilling).

Here's a pretty good shot of the completed frame. See the wire tie loose ends on the top right poles? Trim those extra bits off before we wrap in the the next step.

Tags: greenhouse, pvc, roof deck

Here are a few "blow outs" my greenhouse experienced over the winter. I captured the images them just before taking down the greenhouse in March.

The above is a pretty big tear in the plastic in the lower right hand front corner. It came late in the season so, as you can see, I just used it as a way to easily run my watering hose into the greenhouse.

The image above shows how I repaired two large tears. One was between rib 2 and 3 and the other between 3 and 4. I took tears in the structure rook very seriously because of the potential loss of heat. The repair strategy was to lay new large sections of tarp and anchor those pieces to the ribs. As you can see it was pretty ugly. However it was very effective.

I'll post some other 'blow outs' shortly and include them in a "How to Prevent" and "How to Repair" sections.

Tags: greenhouse, pvc, roof deck

Spring is here: Pictures from '06 Blizzard

Spring has arrived in New York. Here is an over due picture from our '06 Blizzard. Greenhouse, plants, and shrubs all survived!!

I will be finishing the step by step guide shortly. I also have some images of greenhouse wear and tear form the long winter.

My greenhouse is dismantled and stowed neatly away fro the nice weather. I have images and tips for the whole thing.

Tags: greenhouse, pvc, roof deck

Images in PVC

Finally put the finishing touches on the my door design. Expect some step by step posts this week.

Pictured here is a just a shot I took during construction. Nice fall day. The block and tackle in distance was some roof work from a few doors down. "Old First" church steeple in deep background

Tags: greenhouse, pvc, roof deck

My heater arrived

The heater I ordered just in time. It has been unseasonably warm in NY lately. It seems as if it is going to drop below freezing every night for a good ong while.

I bought a small heater from littlegreenhouse.com. I had a great buying experience. I call it 'small' because the 'heater calculator' on the littlegreenhouse site reommended a heater about twice the size. I was a little nervous about 'over doing' it so I went for a less powerful unit. They recommended something that could kick out more than 7,000 BTUs. This one delivers more in the range of 5,000. Any thoughts? Advice gladly accepted.


The description of the heater is below.



Dayton 120v Electric Heater
This 5,120 BTU Dayton heater is an economical option for heating small greenhouses. Features: multiple heat settings (1300/1500 watts) and "fan only" setting, built-in dial thermostat, safety tip-over and overheat protection, quiet circulation fan which distributes heat evenly throughout structure, long-lasting permanently lubricated motor, finger-proof intake and discharge safety grills, and 20-guage steel housing with scratch-resistant, baked-on, enamel finish. Measures: 16"H x 10"W x 8"D. Requires 110/120 volt outlet. 12.5 amps

Tags: greenhouse, pvc, roof deck

PVC Greenhouse: Square Support Structure

While it is really not sqaure, it does have a lot of right angles (coompared to the ribs) so that's why I call it the 'sqaure' structure.

The square support structure is critical to the stability of the greenhouse. Some recent weather in my area had winds and gusts exceeding 50 MPH. So far this appears to be no problem. The ribs will flex nicely, taking and absorbing the wind. The square structure held firm with little sway.


Let's Begin

For starters, friction fit the square structure for now. Do not glue since there will be modifcations for the door after it is assembled.

Cut four 6-foot length of 1" PVC. These four poles will be the uprights. The rear wall of the greenhouse is not a door. A horizontal cross bar will add some necessary support to that wall. To add that bar, cut two of the 6-foot length in half. Insert a 1" T into each with the short open portions of the T facing each other. Cut a 3-foot piece of 1"pipe for the horizontal bar. Insert into the T-fittings to form and 'H' shaped structure. See close up image below



Cap the top of each up right with and elbow with the open end facing the upright on furthest opposite end of the greenhouse. Measure the distance between the uprights. When we started, this was going to be 10 feet. Due to the 'spread' in the base (discussed here in "PVC is not an exact science") this may be more like 11 feet. If you insert the 10 (or 11 ft.) lengths you will have a structure that resmebles the photo at the very top of this post.

Good so far? Let's continue.

(I've seen PVC plans that recommend inserting rigid metal pipes into the long horizontal lengths of the square structure. This seemed especially key if you want to hang planters. I'd have to agree considering they bend slightly under their own weight. Planters would seriously bow this without added support)

More Horizontal support
The front and rear walls need a 3 foot horizontal bar at the top of the uprights. This is tricky since the top of the uprights already have an elbow and that is used for the 10 foot supports. The key here is to make a small one inch cut in each upright, insert a T fitting between the ramainder of the upright and the one inch cutting, and cap with the elbows. See image below.

The above is a side view of one upright. Below is an image of the same from another angle.

You can see how the upright has a horizontal bar at the top but also the elbow. Below is a pretty good shot of th completed structure. (My image has a few ribs already added. We'll get to that in the next step)

Tags: greenhouse, pvc, roof deck