In my experience the more couplers you add the less flexible the hoop becomes. Why all the couplers? Are they straight or custom angled couplers? Do you have a sketching or link to design?

Eric

Are you trying to build something like this?

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I would suggest that you do not use any connectors in the ribs. They do not hold up, IMO. I uses a single 20 foot piece for the ribs and 45 degree elbows on the sides.

I can share more, if you would like.

Jay

Jay,

WOW! Share more. I rifled through your photos, hope you don't mind. You have some Farmers Market photos you should share on the link below.

Eric

Here is a link that might be useful: Photos of Farmers Market

I wish I could post my design print, but I don't have a working scanner ATM. Thanks for the advice guys. The couplers and connectors are to give the structure more rigidity, I was thinking that would be a good thing. Yes, I was hoping that the PVC could bend a little...however, I wondered about the severity of the angle in my design.
Jay, that's a nice lookin house you go there. So, I start hearin about the 45 elbows again - it's the way to go you say? You know, I started looking at all the connectors and put them together like legos to make my design. I've never worked with this grade PVC before though, or built a greenhouse before - hence the post.

A couple questions on your design Jay:
1. What is the height of that house?
2. Appox spacing of the vertical 2X4's running the length of the house?
3. Approx hieght of horizontal 2X4 running length of the house? and did you sink them into the ground at all?
4. What are you using to connect the spine (is that also called a purlin?) PVC? is that more conduit strapping?

A couple questions on your design Jay:
1. What is the height of that house?

It is about 8 foot tall I can stand inside of it, I am 5'10" and reach up and touch the plastic in the center.

2. Appox spacing of the vertical 2X4's running the length of the house?

I have them spaced at 10 feet and 12 feet. I built two of these buildings last year. One at 10 and one at 12. Both worked good, but the 10 foot seemed a little stronger. If you are concerned about strength, I would go down to 8 feet. The 4 by 4 posts are set in the ground 3-4 feet.

3. Approx hieght of horizontal 2X4 running length of the house? and did you sink them into the ground at all?

Look at previous answer. I sunk 4 by 4's in the ground 3-4 feet. The side walls are about 4 feet tall.

4. What are you using to connect the spine (is that also called a purlin?) PVC? is that more conduit strapping?

They are connected with carriage bolts. Good and Bad. Good, easy to use. Bad, can come undone, if not watched carefully also, need to be very careful when drilling the holes.

I also ran a 2 by 4 the length of the building with two posts in the middle. This added tons of strength. It probably wouldn't work with out it.

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Here is a picture for the scale of these buildings. They are 18 by 42. I am standing on a 6 foot ladder. I am 5 ft 10. You could make them wider by adding a piece of pvc to the 20 foot pvc, but in my windy locations, I wanted to keep a lower profile.

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I am bending a 21 foot piece of chainlink top rail to replace some of the bows. THis will make it much stronger, I hope. We had a windy summer and lots of storms. Winds in the 50-70 mph range. Didn't lose them, but I was worried a few times!

I lost both this 12' wide house

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and this 30' wide house

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to snow.

I no longer trust anything that doesn't have a good sharp peak.

Dan

Dan,

What materials are those houses made out of? Steel or PVC?

Jay

Sorry for your loss.

Dan, what method did you use to secure the plastic to the house?

-looking for a scanner to upload my revised sketch.

-BTW - is it still a bad idea to use PVC connectors if I'm bonding them with PVC cement?

and - anyone know where to get furniture PVC at lengths of at least 16'?

I have never heard of furniture grade PVC. I googled it and found a few places that carry it. I guess why would you want to use it? It sounds like it will be more expensive. I guess I learn something new everyday.

About the connectors, I had bad experiences with trying to cement to ten foot pieces together to make a 20 foot hoop. Many of them snapped. The ones that held eventually gave out and came apart. I have lots of experience with PVC. I have build/rebuilt/repaired lots of plumbing with PVC in hog buildings so I know it wasn't my inexperience. I even bought new cement and cleaner.

If you use too many connectors, you will get more $$$ wrapped up in connectors than if you would use solid piece of pipe. For example. If you build a hoop building like mine and used a four way cross connector in the middle, it would cost 2.20 each, 45 degree elbows are .99 each times 2, then you will have to buy the pipe. The connectors are $4.20 and the 20 foot pipe is $6.99. So the connectors and pipe are $11.20 and the pipe and two elbows are $8.99. If you are looking to save money, I would not use the connectors.

I feel that the connectors are the weak spots.

Just my two cents!

Jay

Jay,
You must be a math teacher. LOL

I've experience the same issues with glued up pipe. Much smoother bend with a clear length vs glued up length of pipe. If I understand PVC glue correctly its not really glue but a solvent. The pipes are melted together. If you apply to much solvent it weakens the connection. Bend some pipe with connectors. You'll see an arch, a flat spot and the arch continues.

Eric

Jay, the first one was 1" PVC conduit. It was a 20' stick made of two sections glued together spanning 12'. It had a 1" PVC conduit purlin down the top on the underside of the bows, attached with 1/4" carriage bolts. The second one was steel tube. I don't remember the exact diameter but it was the standard stuff in the 1.6" range. Every second frame had a collar tie about half way between the ridge and eave heights. There were three purlins.

Mike, I used wiggle wire on the end walls and lath nailed through the plastic and into the sill on the sides. On the metal house I used wiggle wire all the way around.

jrslick's house looks nice, and maybe with the heavier framing and Kansas wind there won't be any problem with snow build up. I'm sure it's possible to build something strong enough. But I find more peace of mind in building something that will shed snow. Just saying.

Dan

Dan: My buildings to hold up well to the wind, but snow is another story. I am going to add a steel rib every 2 ribs. I am also going to add another purlin on each side. I will add some temporary supports for early spring and late fall/winter production. I would like mine to shed snow better, but I can't make it work for everything.

Jay

Thanks for the reply. It's good to hear from the voice of experience. I will certainly avoid PVC connectors now,...sounds like it would turn into a nightmare. Just to show how good it looked on paper tho.......

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I started looking at PVC because I didn't know where I could get nice metal pieces....of course, as far as a hoop goes, you can't exactly bend it yourself, although, I imagine it is easy enough to use a conduit bender to make 45 angles....not sure if 90 is possible. I started the desgining process because I thought I might be able to do it cheaper than buying a kit. Perhaps one of the more difficult things for me is the size I want. I'm trying for a 20'W X 48'L X at least 10'H. The other problem is snow, huh Dan? I live in western MA, we can get a lot of snow. I like how you are using vertical central supports in your house, Jay....that's gotta help some.

So I need to think about re-designing now that connectors are out of the picture.... I am left wondering how wide your house is, Jay.

Mike, With all those connectors, you would spend a small fortune. I am glad you are looking at cutting them out. I would suggest that for the side wall attachment on the bottom that you drive a 1 1/4 inch PVC pipe I foot long into the ground and slide the sidewall/bow pipe into that. I will try to find a picture to show you. This way you don't have to try to attach it at two places. Also, If you are going to go with a one piece hoop, glue the 45 degree elbows to the side pieces and leave the rib connection unglued. The down pressure from the plastic will keep them together. The elbows will come off in fierce windstorms, not as big of a problem after I started to glue them. Also if a rib breaks, you can easily replace them.

You can bend a piece of chainlink fence top rail to match the plastic hoop. I used my endwall pipe and attached more 2 by 4 pieces under the pipe and attached the pipe to one side and "walked/bent" it over the hoop. It was fairly smooth. That is what I am doing this year to add some strength.

My building is 18 feet 6 inches. You could make your 20 by adding probably 3-5 more feet of pipe to the 20 foot rib. If you do this make sure you buy the pipe that has the bell end. (FYI it is a built in connector that you can connect two pipes together. This connection is stronger than the connectors you buy at the store.)

You can add a side support 2 by 4 like my center one on each side. I was going to do this and put the post in the row of tomatoes. That way it would not be in the way. Snow is a concern and if you are patient and diligent, you can sweep it off and you will be fine. The light fluffy stuff isn't a problem, the wet slushy stuff is a nightmare!

When I build my building, I had plans like yours. I read everywhere and I figured my costs. If I wanted to build a steel frame building the same size as mine, it would cost 4,000-5,000. I could not justify that expense. Mine cost $500-$600 depending on how you account for materials on hand and cheap buys on craigslist. I decided I would get up at 2 am and sweep snow if it was going to save me $3,500-4,500 up front. I also am concerned about tornadoes here in Kansas. We have had close calls from them every other year for the last 6. This is an on year. Close calls means, tornado on the ground with in a 1/4 mile of my house. We will see what this year brings!

Good Luck.

Tornados... I am NOT in the same league!

Lots of good material in here, almost makes me want to put my hh back up.

Are you all using GH plastic, or what? How much dough does it take to cover these structures?

sfallen: I use Klerks K-50 poly. I get it from Stuppy's Greenhouse in Kansas City. I pick it up at their offices. I paid $281.42 last year for a 32 by 100 roll of plastic. So for under $145 I can cover each of my buildings. BTW, We have to visit a Childrens Hospital for one of my girls. So, I pick up a roll when we go and I save on shipping.

Jay

I'm bumping this thread because I like it so much.

Jay, if you're still on here at all, thanks for posting all of the pics on this thread. I plan on building a copy of your structure this winter.

What keeps your sides up when you pull the plastic up to vent? I have roll-up sides on my current greenhouse that don't work so great.

How did the change to two rows of support post modification go? Did you like that design better?