Hoop-houses in high wind

We've got three 10X40 feet hoop-houses constructed with PVC and 6 mil polyethylene.  Anticipating a windstorm, would it be more effective to anchor the sides with weight or roll up the polyethylene as high as will go to reduce sail-away?  Any experience with this out there?  Thanks!

We have lots of plastic greenhouses and we find the best results from making sure there's a couple extra feet of plastic at the bottom, and weighting them down. We are in a very windy location.

In addition to her idea to make longer sides and place weight/ballast, i have been thinking what to do

There is /are video on youtube if you search for hoop greenhouse, high wind, snow load type words.

Some folk build an inner wooden frame with ridge beam and other ways to secure the hoop to a heavy inner structure.

some attach the hoops to wood base with metal strapping.

I am thinking to create raised beds next to wood base and the weight of those will be ballast.

hope this helps
blessings on your adventures

I have hoop-style greenhouses in windy conditions, sometimes gusts up to 75 MPH   I use strapping, like the 2" wide fabric strapping truckers use to tie down a load, and zig-zag it back and forth over the top, starting at one front corner.  A good sturdy rope works well, too.  

In the winter when I am not using them much, I cover them with tan shade cloth, then zig-zag the rope or strapping over that.  It helps the plastic or panels last longer, and shade cloth is a good wind block, it allows a little flow through it, but doesn't act as a sail.

Anthony Hardt wrote:We've got three 10X40 feet hoop-houses constructed with PVC and 6 mil polyethylene.  Anticipating a windstorm, would it be more effective to anchor the sides with weight or roll up the polyethylene as high as will go to reduce sail-away?  Any experience with this out there?  Thanks!

THinking that since a hoophouse is round, that if secured properly with maybe several ways of being secured,
that the wind blows over/around the structure.

If you rolled up the sides,would that make it more like a parachute to catch teh wind? anyone have feedback for this?

In addition to what others have said, your vulnerability depends upon two primary factors: location and orientation. If your hoop houses are located in a valley, you are safer than if they are on the crest of a hill. If wind direction is, for the most part predictable, and wind regularly strikes the upside of a hill, then you want to construct yours on the downside or in the valley close to the downside.

It is true that wind will tend to roll over your hoop house, but only if it is properly oriented to receive wind on the sides and your covering is pulled taut on the frame. Height of the hoop house relative to its base also is a factor. Hoop houses with high ceilings should have wide bases. This effectively reduces the angle in which the wind hits the house, deflecting the energy wind of the wind over the house. The closer the first 6 feet of the the walls are to 90 degrees, the greater the probability for damage in high winds.

With a PVC hoop I think I would most likely roll the plastic up.  The film needs to remain as tight as possible to reduce wear and tear, once that sucker starts flapping it's done for.  Usually the PVC hoops are not sturdy enough to maintain that tight film, they tend to rock back and forth and buckle.  If you've done a lot of reinforcement you might be Ok.  I would err on the side of caution if it were me.

We have a commercial style hoop (16x24) with metal hoops,bracing and perlins that we leave up year round with no problems in our high winds (pretty commonly in the sustained 40 mph range), it's all about maintaining that rigidity though (no floppy plastic)!  

I know high winds can be troubling, but now I'm taking a different approach.  
I've built 3 foot walls all the way around, with about a foot of 1/4" hardware cloth mesh on top for animal and wind control.  My mesh shade cloth top also serves to slow down the wind.  Wind is not always the enemy... too much wind is.  This gives me the high altitude shading I need to prevent scalding from the sun, it slows down the highest of winds, gives me adequate critter protection, so far, and still gives the surface a chance to breathe.  I would go higher on the side walls, and electrify if needed, but so far only the coyotes are jumping the fence and they could care less about my green plants.  The 20X40 hoop-house is anchored in the ground with cement on all hoops, but I would probably just anchor the corners next time.  The sides are made of 2X10 treated lumber to resist rot.  The shade cloth is blocking 18-20% of the suns rays, and so far is just about right for Northern AZ, at 7,000 feet.  I no longer try to keep all the moisture out, and all too much heat in, and I'm much happier, and more maintenance free.

Dean, do you get snow in your area? Do you find that snow builds up on the shade cover? I'm wondering about going with shade cloth instead of plastic film here in Colorado, but I'm wondering about snow load; it wouldn't slide off.  

Yes. I can get a few 15 inch snows.  
No, the shade cloth does not hold up to more than an inch, or two of wet, heavy snow load.  The folks that sell the shade cloth intend for you to remove it every fall, which is work, but it will also last longer if stored out of the weather, so that's a plus.

Dean, I live in Cochise county and really like your hoop house. I agree that the wind could be mitigated but not eliminated. I have a lot of wind here and that plus mitigating the vermin threat is my main concerns. I'm wondering if using a galvanized steel bug screening would be a more permanent material than synthetic sun screening?

I did surround the hoop house with a 2.5 foot high band of 1/4" galvanized mesh and a hipboard.  Most insects stayed out with this visual barrier, but a finer mesh would work even better.  The fabric mesh on top was a little for wind, a lot for sun, and worked great in hail.  Good luck down there!

I have a 12 x 24? Ft high tunnel ....8ft high. I am in a tornado belt.  I keep mine tied down in storms.  It is well anchored.  The steel frame sits on a foundation of 4x6s.   This keeps the metal off the ground, adds some weight, and provides a margin of safety from weed cutters.   I have it tied down to both the wood foundation and 8 screw in anchors .  Those anchors each have 100 pounds (dry weight) concrete on top of them.  I have never had a problem.