High Tunnel Advice Needed...

[DoobieDuck]

Friends I am putting up a high tunnel. This is 30 feet wide by 20 feet long by 12 foot high. 1 1/2" pipe, hoops are on 4 foot spacing. My concern is wind. I live in a high wind area, I have researched the internet and find contadicting advice on how to face this. It seems most say face an end into the wind, so wind would blow down the 20 foot length of the structure. My question is the flat end would be 12' by 30' and that would create a lot of resistance, need anchored quite well in my area. It is not secured to the ground yet so it can be moved. Hit me with some pointers guys, thank you, DD

 

[IWanaGetHiSoHi]

Add some ribs perpendicular to the "ends" and make it pill shaped with an igloo type bump out door. That way you can still work in a louvered vent system above the door to direct the air flow through the tunnel.

 

[humble1]

farmtek has a fabric for greenhouse/hoophouse setups that has a low diffusion rate for sunlight, is permeable to air and water, but fine enough to exclude insects and unwanted pollen. That's what I would try.

 

[nomaad]

Put diagonals between as many of the hoops as possible... up down up down along the length of the structure....

I would call farmtek and ask to talk to one of the greenhouse techs... they put these things up all over the midwest.... it gets windy as fuck there.

 

[DoobieDuck]

Iwanna thank you for that..I might try that idea. Humble and Nomaad.. I ordered all my channel and film through Farmtek and my order has been shipped..is on the waty, so I gotta get my ass in gear. The Tech guy there at Farmtek says point it into the wind so I will have to spin it around, not really a problem as it is not secured to the ground yet. Nomaad I have some 8x12 beams I'm rippin in half for uprights and to frame in the ends. The more support the better. Thanks guys...appreciate all your help...DD

 

[humboldtlocal]

I would also add a row of 2x6 along the base of the walls for added strength. I have seen a lot of these and this seams to be what they really need. Definitely anchor it down as well. I have seen them blow over in strong winds. My friend who installs them recommends removing the plastic for the winter. I don't know if that will be an option for you though. Congrats on the greenie as well. Hope it provides plenty of meds and lots of beautiful photo ops. Can't wait to see some more pics.

 

[esbe]

wow doobie bro, thats so cool! cant really help as my gh is glass.

 

[DoobieDuck]

Hope it provides plenty of meds and lots of beautiful photo ops. Can't wait to see some more pics.

HBL hey thanks, just what I'm putting it up for is images and I hope to provide some dandies for you all. I already have the 2x6s already to go on, I'm just waiting to treat them first with preservative. I have 22" 2" pipes that each will be cemented in the ground and each hoop will slip down into these and be bolted. I know a guy that cemented his right to the ground and had to pay, still pays, property tax every year. So far I've done all the work myself, includung erecting this baby..that storyand pix I might put up as it was a three day major event. I have to give my body a much needed break for a couple days. Thanks Esbe...DD

 

[ROOTWISE]

Doobieduck-

Groundboards (as humboldtlocal said), concrete piers, angle bracing, and double layer inflated plastic all contribute to its wind resistance. We actually doubled up the groundboards on the windward side of my first greenhouse. Are you doing the double layer with blower plastic? We sink all of our ground posts 24-38" inches in concrete here. Just dug 22 of those holes by hand yesterday.......

Also--how many purlins are you running? Maybe beef up that number as well....

We get crazy wind and snowload here and no problems yet...

Hope that helps..

 

[DoobieDuck]

Root many thanks..purlins? I'm not sure what you mean by perlins. I doubled the end hoops by adding an extra to each end. I added a center pipe down the top as it only had two on both sides of center of the top. That is much deeper than I planned on sinking my ground holes...may I ask how large the holes you use are across? No I am not going to use a double layer as I only plan on using it in the best part of the year. We get 15 below here and I don't think plants would survive that even with double layer plastic. The wind blows here..sustained 50 mph yesterday with 80mph gusts..it blew over a semi truck on the highway 10 miles from my home yesterday!...a big reason for this thread. DD

 

[supermanlives]

lots of extra perlins and secure well. good luck i had a few smaller ones along with 96 ft ones. farmtek has great rollup sides for ventillation if stealth aint a concern. got a few random pics left in my gallery. i set mine up for how the winds tended to blow as when i rolled the sides up a little for ventillation.saved me lots of electricity on fans.

 

[ROOTWISE]

DD- Purlins are the "horizontal" pipes (you added the one at top) that give the entire structure its rigid strength. I'd probably add a couple more. You don't have to use holes as deep as mine as I'm putting up much larger and heavier structures. My holes are about 8" in diameter. You could certainly modify that but as long as you've got that house anchored in some concrete you will sleep better at night...

With the kind of wind you are describing I would go the extra mile and install the double layer plastic, I don't grow "out of season" either but the air bubble that it creates really helps insulate in Spring/Fall, never mind the structural integrity it adds. The tension it creates gives the whole greenhouse an aerodynamic quality and the wind never really gets to fill up that plastic and create the "Sailboat Syndrome" that will flip a high tunnel inside out....I've seen it happen twice at my buddies 40x90!!! Lucky he's just growing veggies for Farmer's Market in it....!!!

Sorry if I'm creating too much work for you and I hope I've helped your plans...

(Love your photos!! I'm a Canon 40D guy and a rookie waterfowl photographer!! Small world)