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Diy steel hoop house.

P-NUT

Active member
Veteran
Anyone ever setup a roll up side greenhouse to unroll shade cloth so you get ventilation but people can't see? I'm thinking a bar that's spring loaded like a garage door that rolls it up then the poly comes back down. What's y'alls thoughts?
 
I have had greenhouses sitting on mountain tops that get 60mph winds every year.. Each hoop bolted to a post that is 3 feet in the ground on both sides... What is going to pull that up?

I don’t know where your greenhouses are located, but by the sounds of it, I don’t know if you are dealing with frost.

Like I said before, frost line around here is 4 feet. It doesn’t matter what kind of soil you are dealing with, because the frost will heave those posts right out of the ground.

Not saying your method of slamming piles into the earth won’t work, but around here having the pipe only a couple feet in the ground isn’t going to cut it. Sure it might get you croppin for the season, but I’d be worried come freeze/thaw cycles :joint:
 

CrushnYuba

Well-known member
I don’t know where your greenhouses are located, but by the sounds of it, I don’t know if you are dealing with frost.

Like I said before, frost line around here is 4 feet. It doesn’t matter what kind of soil you are dealing with, because the frost will heave those posts right out of the ground.

Not saying your method of slamming piles into the earth won’t work, but around here having the pipe only a couple feet in the ground isn’t going to cut it. Sure it might get you croppin for the season, but I’d be worried come freeze/thaw cycles :joint:

You have to understand the way frost heave works. If you put a concrete pile in the ground without using a form and mushrooming it below the frost line, it will heave because it's a large rough surface for expanding soil to grab onto. A 1 5/8" steel pipe driven into the ground is smooth and has a much smaller surface area so freezing,soil can't grab It.
We aren't making footings to hold up a deck in the air. Footings are to hold things up and prevent a wood structure from making ground contact. We are just trying to hold a lightweight structure DOWN.

think of a ground post more Like a big tent stake then a tiny footing. It's not Like steel hoophouses are some new thing we are pioneering. This isn't theory. Steel ground posts are standard. They have stood the test of time in every climate. When the ground freezes and expands, it just slides up that hollow steel post.

It should be noted that for the same reason a ground post won't heave, it also won't stop your greenhouse from sinking. That's what the wood base and proper drainage is for.
 
Anyone ever setup a roll up side greenhouse to unroll shade cloth so you get ventilation but people can't see? I'm thinking a bar that's spring loaded like a garage door that rolls it up then the poly comes back down. What's y'alls thoughts?
You are over thinking this. Just install permanent privacy/shade cloth to the inside of your GH from the baseboard up to the hip board. Same as you would install chicken wire to keep rabbits out or razor wire to maim children.
 
. When the ground freezes and expands, it just slides up that hollow steel post.

It should be noted that for the same reason a ground post won't heave, it also won't stop your greenhouse from sinking. That's what the wood base and proper drainage is for.

So these greenhouses you build on top of mountains with 60 mph winds.. how many years do they last?

Another thought to consider, when the ground freezes with now compacted dirt in your tube, I don’t care how smooth the pipe is, it is now a solid piece of pipe.

Not saying using the tent spike method wouldn’t work, just your pipe/stake would have to be “below” the frost line. What happens when you hit a rock, or your working with heavy clay? You seriously going to stand there and drive a pipe into the ground that deep with a sledgehammer? What are the chances of using a demo hammer with a driving plate on it?

Not saying screw piles, or sonotubes are the way to go, but this “lightweight” structure that has been put up could potentially act as a sail, so it’s up to whoever is building it to act accordingly.
 

CrushnYuba

Well-known member
So these greenhouses you build on top of mountains with 60 mph winds.. how many years do they last?

Another thought to consider, when the ground freezes with now compacted dirt in your tube, I don’t care how smooth the pipe is, it is now a solid piece of pipe.

Not saying using the tent spike method wouldn’t work, just your pipe/stake would have to be “below” the frost line. What happens when you hit a rock, or your working with heavy clay? You seriously going to stand there and drive a pipe into the ground that deep with a sledgehammer? What are the chances of using a demo hammer with a driving plate on it?

Not saying screw piles, or sonotubes are the way to go, but this “lightweight” structure that has been put up could potentially act as a sail, so it’s up to whoever is building it to act accordingly.

The greenhouse frames last indefinitely. The plastic needs to be replaced every 5ish years. I have seen nurseries and schools with steel frames that are super old. My buddy has a 30x40 at 4000ft that was There when he bought The house 15 years ago. No concrete. Rock floor.

I have been growing my whole life. I see a structure on the side off The road and i stop and check it out. The first steel frame i built was almost 10 years ago. It's still standing. It was a Kit that came with ground posts. Long before i ever bent my own frame.

Depending on what type of ground it is, it can be hard to drive them in. Its mostly red clay where i live now. There is a ton of rock. This area was settled by miners. You do it when the ground is wet. You can use a driving cap but chances are it's getting mangled a little anyway where you beet it. You just saw off the mangled part flush with your wood base. It isn't that hard. I do It all the time and i documented It in the first half of the thread. you hit rock on a couple posts, it's no big deal. Just get it down as far as you can without it going crooked. It's bolted to The wood base anyway. When you excavate your pad you try to pull out as many big rocks as you can. I wish The pictures earlier in this thread weren't deleted because i went over what to do when you hit rock. It's been a couple years and The image host deleted them. I went over a full build pretty much instructional style.

The matter what, any concrete in the soil above the frost line is going to want pull the pile up. That's why you mushroom it out significantly at The bottom of the tube below The frost line to anchor it down. The deeper The frost line, the more freezing soil is making contact with concrete, the harder it is. with a steel pipe there is no mushroomed concrete below the frost to act as an anchor. So it really doesn't matter if you get it below The frost.

Think about this.. A 100ft long hoophouse will have 52 steel ground posts banged 3ft into the ground. That's allot of pipe anchoring it. It's also a ton of plastic to act like a sail. But it works. Getting the posts out once they have been banged in and It's rained a couple times is really hard. You can't just pull them up by hand.
 

CrushnYuba

Well-known member
So this is a prime example of if the ground post method holds up to wind. There is a storm RIGHT NOW. Gusts of 50-60mph winds. It's crazy out there. I wish You could see it. This is NOT uncommon for this area. Trees will uproot but the greenhouses won't budge.
Screenshot-2019-01-16-21-30-55.png
 

Bleiweis

Active member
Veteran
Hey CrushnYuba!

Great thread you've got going here! I first wanted to fit a dehuey in my soon-to-be greenhouse but thanks to you i've decided to install a proper heater! Would anyone care to comment on a few points i've come across?

My greenhouse size will be 15-20 feet long, 10 feet wide and 7 feet at peak height. A small greenhouse :) here we have hot summers and usually wet and a cold falls. I plan to run my heater in september and october...by then usually all of my plants finish :) my main concern is high RH during flowering due to which i usually lose a lot of flowers.

1. I can choose between 4mm,6mm,8mm and 10mm twin-wall polycarbonate. Should i just choose 10mm if i can afford it or will that be an overkill during the summer? I don't plan to provide cooling in my greenhouse. The standard here is 4mm and sometimes 6mm.

2. How many times per day should the air be changed inside the greenhouse? I plan to use 1 exhaust fan (1600 cfm or greater power) and two intake shutters on each side. To keep the humidity low i plan to exchange the air in the morning/during the night and then heat it so my RH drops.

3. I plan on using 2 electric-ceramic heaters (2-3kw each...online calculators say i need about 15.000 BTU's to heat effectively). Where would be the best place to put them? Blowing hot air directly into the plants is probably a bad idea?

4. I have the option to install a roof mounted automated window. I guess it would do good during the summer? Yes or no?

5. We have good soil here so i plan to plant directly into the ground. I should probably provide some cover so the water doesn't evaporate directly into the greenhouse and cause RH issues? Geotextile maybe? Your thoughts on this.

I'm planning to eventually trick out the greenhouse with automation based on raspberry pi.

I will be very grateful to everyone who provides an insight on this! Kudos
 
Found some used pipe arches which will be cheap or free.
I’ve got a couple of roll-up motors a power supply and timers for the auto-dep.
Ive got the acres to put it on.
I’m currently multiplying plants to put in there.
Fucking stoked!
 

TychoMonolyth

Boreal Curing
I anchored mine pretty good, but the wind picked it up like it was paper and put it in the bush three times before I called "uncle". I had steel pipes 3 feet in the ground. Total waste of time.

picture.php


Pipe came from a car coverall that was wrecked by snow the previous winter. I'm putting in a permanent 10x12 garden greenhouse. Fuck it.
 
We’ll see. I’m building it in a protected area though it is windy as fuck here, most days.
I can build it so the posts won’t pull out.
The supplier I intend to use sells a zipper-like fastener that you can “Un-zip” and tighten the poly to keep it drum tight.
I know what I’m up against and will build accordingly.
 

CrushnYuba

Well-known member
Can you post a picture of it? Is it a standard greenhouse 24v roll up? How wide is the house? I usually use 1 3/8th top rail for the rolling pin. The top rail is nice because it's swaged. It fits into the next length nice and tight without having to use some sort of coupler that would make the bar floppy.
The motors i usually use do 35 revolutions i believe.. But i have used them on a 18ft tall 30ft wide gothic arch.

If you need help with mounting a roll up side or light dep bar, let me know. There's really only one way to mount the light dep bar, but there are a couple ways to mount the roll up sides.
 

CrushnYuba

Well-known member
Bjorn to farm: what type of zipper fastener are you using? Channel and wiggle wire works really well to get that drum tight cover, if you do it right. You have to install it on a hot sunny day.* During the day, the plastic heats up and it stretches a little and gets slightly looser. Then at night it tightens back up... Even with all the expanding and contracting, if you do it well, you will get a few years before you start to get any noticeable sag.* Regular 4 year 6 mil poly is easier to get that drum tight cover then a heavier weight scrim reinforced or woven poly.

I know allot of people have expressed concern about anchoring for wind, but it's just theory and its really not as bad as they think in practice.* Everyone has had a temporary structure fly into a tree at some including me. There is a big difference between a flimsy temp structure teathered to the ground with some sort of stake and a rigid bolted steel pipe structure that each hoop extends into the
gound 3 feet.
Never have i seen a proper steel kit or diy top rail with ground posts lift.* More of a concern is the structure racking from wind. If It's braced correctly, it's easy to prevent, but i have seen quite a few rack that were not. It's more sheer load you need to worry about then uplift.
 
My motors are 24v jobs from China. I need a controller though.
I was thinking big pipe so it would travel further and I could use just one to go the whole way.
That poly fastener is in the PDF I posted.
 

CrushnYuba

Well-known member
When you say big pipe, do you mean long pipe or big diameter?
It would only take 2 pieces of 10ft top rail to go down a 20 ft long hoop house. They also make 20ft long top rail, but top rail nests into the next piece so well, i don't see the point.
You could build your own "controller" with a few parts if you are comfortable with some very basic wiring. Doesn't require soldering. Just a screw driver and some wire to connect 3 components. I could pm you a wiring diagram and parts list.

Edit: it seems like you mean bigger diameter pipe. You will need 2 motors for black out regardless. The bars need to rest in the center of the greenhouse when open. Maybe i have to take some more pictures to share
 
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