Build-A-Long with Stinky: $150 PVC greenhouse

[stinkyattic]

One of my co-workers is constantly bugging me for garden advice and loves Italian food... Since my saltwater fishing trip plans got rained out this weekend, we got a bright idea to build her a greenhouse instead so she can grow enough tomatoes and peppers for herself (and the rest of the county).

The finished size is 10' x 20' and will be an insulated structure framed in PVC and sheathed in 6mil poly. It will be strong enough to hang minimal lighting from.

So here's the parts list:

16- 1/2" x 10' PVC poles (secondary ribs)
6- 3/4" x 10' PVC poles (primary ribs)
2- 3/4" x 10' PVC poles (ridge pole)
1- 3/4" straight coupling (joins two halves of ridge pole)
8- 1/2" non-threaded PVC 'elbows' (ridge connectors)
3- 3/4" non-threaded PVC elbows (ridge connectors)
4- 1" PVC poles (to be cut for base receiver poles for the secondary ribs)
2- 1 1/4 or 1 1/2" PVC poles (to be cut for base receiver poles for the primary ribs)
1- package of assorted ZipTies
2- Rolls of duct tape- get the good stuff, trust me.
1- 25 x 100' roll of 6 mil clear poly sheeting
1- 4" inline fan with power cord (optional)
1- length of 4" ducting (optional)
1- 4" ductwork flange piece (optional)

Enough heavy tarp material to cover a 10 x 20 area
Lots of used shipping pallets

You also need tools:
Chop saw
Small iron mallet
Sharpies
Drill with 1/8" bit
Ruler

Things that will make your life easier:
Measuring tape
String for laying out the form of the structure

[stinkyattic]

First mark out the area where your greenhouse will be. It will be 10' x 20' and should get at least 6 hours per day of full sunlight, preferably early in the day. If there are weeds and brush, rake them off as best as possible so the 'floor' is smooth and won't poke holes in the tarp you will lay later.

Lay out your supplies and tools first. It's helpful to have a nice flat area to work on. If you count, you'll notice that we forgot some poles, and Home dePOT was out of elbow connectors so there are some of those missing too.

Your first step is to cut the receiver stakes.
First, mark 4 of the 1" poles and 2 of the 1- 1/4" poles off into 2-foot increments.
Cut with the chop saw set on 90' into FOUR foot sections.
Re-set the chop saw to 45' and cut each section in half into TWO foot pieces.

At each corner of the greenhouse, and at the 10' (middle) point of each long wall, pound in a 1 1/4" receiver stake. These will hold the primary ribs.

Along the long walls, pound in the remaining, smaller (1") receiver stakes spaced 2 feet apart. These will hold the secondary ribs.

Make sure the stakes are PERFECTLY upright. Sink them so that they are HALF buried. One foot above ground, one below.

Pics:
1- Supplies
2- Stakes
3- Layout showing stakes installed (partial)

[stinkyattic]

Now assemble your ridge pole.
There are a few places in this greenhouse where I recommend pinning the connection so it doesn't come loose later; this is one of them. The elbow connectors on your primary ribs are another. If you live in a windy area, you might want to pin all connections.

The method by which I do this is shown:
Lightly spray the pipe ends with cooking spray. Butter flavor works best.
Insert the pipe into the connector, and pound it all the way in with a small mallet.
Drill 1/8" holes through the center of where the pipe and connector form a double layer in the joint.
Insert a zip tie through the holes and zip it tight.
Now the connector can't pop off, and when you want to take down the greenhouse, all you do is cut the zip tie.

Assemble each pair of ribs and its elbow connector the same way. They should form a 90' angle, which you will bend later. Be sure that the connections are all snug using your mallet. Mine is named The Persuader.
You should now have one 20' ridge pole 3/4" diameter, 3 primary rib pairs 3/4" diameter, and 8 secondary rib pairs, 1/2" diameter.

Pics:
1- Pipe ends with cooking spray, yum yum
2- Straight coupler shown with one side pinned and the other side just a hole that doesn't even go all the way through (battery on crappy Craftsman cordless died... I swear cordless power tools are totally marketed towards chicks. I made the switch to corded everything about a week after I bought my house hahahahaha!!!!).

[Weedhound]

Lighting? Do you need it for an outdoor grow and what is minimal? For seeing or for growing?

Very cool.....I may have to try this myself. :thumbsup:

Is it deerproof?

Is the butter flavor a non-interchangable supply? :D

[stinkyattic]

This part is much easier with 2 people.
Stick the base ends of the ribs into the receiver stakes. Now THAT is starting to look like something!

That's all for now; I'm not making the drive out to see my co-worker again until next weekend and will post the rest of the instructions when the thing is done.

Pic:
1- The frame taking shape

[stinkyattic]

Garlic flavor works okay too ;)

Not strictly deerproof unless you add some extra poles or netting. Deer COULD break down the plastic, but it should be relatively easy to keep them out. I may end up trying to do some rodent-proofing on this one, since my friend has a local woodchuck population that made off with all her melons last year. We'll see.

Oh, didn't notice the lighting Q.

We talked about the lighting and yes, it's more for 'seeing' than for 'growing', since the sun takes care of THAT. She works a day job that rarely allows her to be home before 6, so a lot of greenhouse chores will be done at night. We were thinking about just 4- 4' shop lights hanging high from the ridge pole. Each weighs only a few pounds and will give plenty of light to work by after dark.

If you are interested in using correct agricultural lighting, such as 4- 1000w MH lamps with reflectors that are appropriate to what can be a WET environment, I'd replace all the 'secondary' ribs with 3/4" PVC and replace the 3/4" ridge pole with a full inch diameter one, and instead of securing the ridge pole by zipties, use BOLTS.

[stinkyattic]

Heavy clay soil, lol! Them thangs ain' goin' nowheres.

[texas grass]

lookin good
and givin me more ideas to build stuff:thumbsup:

are you using sch. 20 or 40 for your tubing? do you have alot of strong winds?

cant wait to see the finished product good luck and have fun;)

[stinkyattic]

Oh sorry Tex, I didn't read the stuff stamped on the tubes- it's just the cheap, standard home depot grade. We DO get some strong winds, but that location is sheltered from them by structures, shrubbery, and a retaining wall.
I can't wait either! I told her I will take my payment in a couple gallons of home-made spaghetti sauce :D

[texas grass]

yum spaghetti!!! you can can some and share the love:)
you can get both sch. 20 and 40 from the local store
20 is thin wall
40 is thicker wall about twice as thick. if you have stronger winds i would atleast recommend that
and im with you on using 3/4" for secondary and 1" for primary

[Weedhound]

What would be your thought on replacing the plasting with something like shadecloth?

For like.....arial reasons.

Hard?

[stinkyattic]

You could put shade cloth over the plastic, or even build a second, smaller hoop within the first that you could have the shade cloth attached to (if you don't want your shading action to be so obvious to passerby who understand WHY you keep that shade schedule, lol), but your primary sheathing should be poly. The shade cloth is just meant for darkening, not for actually keeping the elements out.
It's not going to be a factor for my friend, who is WAY too paranoid to even CONSIDER growing pot! haha

[stinkyattic]

I re-arranged the receiver tubes so that the primary ribs are at the ends and in the middle. Home Depot STILL didn't have the elbow I needed so I used a T instead for that last pesky missing rib. Oh well.
So where were we? RIbs were almost up. So let's start there. The ribs have to be in place, and then the ridge pole has to go on.
Here's pics if that process.
1- The view down the tunnel
2- Method of attaching ridge pole
3- The ribs need to come together in pairs if you want added rigidity
4- Showing pairs mated- you need to zip-tie them together after sliding them towards the middle of each section
5- Aww yeah, I KNEW all that work putting the Little Giant on the freaking car roof was gonna be worth it. That thing is HEAVY!

[stinkyattic]

Now cover it! We didn't have the time or desire to do a double layer, since it would have entailed ANOTHER trip to home depot and no one was in the condition to be driving, lol.
1- Showing edge clips made of scrap PVC with a section removed at an angle so as not to tear the plastic, idea courtesy of a local greenhouse geek.
2- Marge, Thelma, and Selma stopped by to pull sheeting
3- Some people just NEED dreadlocks. Here's a pic showing the contortions one must go through to attach the flaps over the vents
4- The vent as it looks closed. There's a weight in there. A piece of iron gas line pipe is ideal, but it MUST be significantly wider than the vent hole to work correctly!
5- The ends need work still but it's essentially useable at this point.

[FrostAie]

that is pretty awesome i wish i could set something up like that where I live. I have to resort to fields and tree lines. With risky time consuming waterings

[stinkyattic]

This greenhouse is actually intended to house hot-weather crops: Tomatoes, peppers, and eggplants, and some types of herbs. I told my friend that, especially with lights in there, it would not be a stretch to expect the neighborhood kids snoopin' around to see if they can't steal some pot, or a slow drive-by by her friendly local PD. Some people have the balls to pull off greenhouse grows. I don't personally know ANY of them. That whole idea scares the bejeezus outta me, lol.

[Weedhound]

nice property and house. :thumbsup:

[stinkyattic]

Ugh I know, I WISH I could afford something that nice. These days, you HAVE to have 2 incomes to even TOUCH a decent piece of property! And damned if I'm getting married just to improve my socioeconomic status! :mad:

[Weedhound]

Lol, these days that doesn't guarantee either does it?

That thing is a LOT larger than I thought it was going to be. What do you do about humidity in a greenhouse? They must get mold problems and such.

[stinkyattic]

That's what the vents are for, open the vents, roll up the sides or open the ends, and let thermal currents do the work for ya! :D

[Weedhound]

Well I knew you'd do vents and a chandelier, wainscotting etc but how about the rest of us?? :D