The main change to my building plans is that I decided not to cover it with sheet-metal, but instead I decided to use something like 2x6's or decking boards spaced a couple of inches apart to make it a more porous windbreak (optimum windblocking is supposed to be with about 25-30% porosity).
I don't know how I missed it before, but after looking a few more times at the Portable Windbreak Fences Publication I wrote about before, it finally sunk into my brain that a windbreak with boards spaced about 2" apart, around 80-85% of the wind would be blocked for about 80 feet downwind. With a solid windblock, about 90% of the wind will be blocked really close to the windblock (about 8 feet in my case), but only about 60% of the wind will be blocked farther out.
It's a little counter-intuitive, and at first thought it seems like a solid wall would block more wind, but after some informal testing (I stood in a bitterly-cold wind next to the loafing shed and then walked downwind), and a little bit of observation (on one really cold and windy day, I noticed all of the cattle standing downwind of some parked farm equipment which wasn't anywhere close to being a solid wall), it eventually made sense that a more porous wall would drop the wind velocity more over a larger area than a solid wall would.
It's rare, but it looks like my habit of taking forever to finish a project might have helped this time and when I get around to building a portable windbreak I'll be using 2x6's or decking boards so I can build a more open wall.
Besides changing my mind about using sheetmetal to cover a portable windbreak, I've also decided to do a few more of the the things I wrote about when I was trying to figure out how to build a windbreak.
|How good will those stacked bales work as a windbreak? I don't know, but I'm going to try it out|
So, I stacked up some hay along a fence line inside the hay storage lot. I'm not sure how well it will block the wind since it's similar to a solid wall although because it's hay it might help break up some of the downwind wind current eddy more than a solid wall would, but it didn't really cost anything to build (a little time and diesel), it's better than nothing, and the cattle can't get to it behind the fence (so I won't have to clean up a mess of wasted hay after a storm). As long as the wind blows out of the north, I should be able to figure out something during the next snowstorm (stay turned for that exciting update).
I'm also thinking about planting a line of cedar trees (actually eastern red cedars which are junipers) as a windbreak or shelterbelt out in this pasture which is more of a controversial subject than most people would think it is. Years ago, Grandpa fought a losing battle trying to control the cedars on the farm, wearing out both his body and a bunch of chainsaws in the process. After all that effort, the cedar trees just kept growing back. I've also spent a lot of time cutting down cedars on the farm, which I'm looking at as an ongoing battle instead of a war I can actually win, and I hopefully won't wear my body out quite as much or as fast with that mindset.
But I've also been thinking that all the bad things about cedars might also make them a good choice as a windbreak if I manage them correctly. They grow quick even in a drought, are thick enough to block a lot of wind, and if I plant them up on a flat spot instead of down along a creek then there should be less chance of erosion under the trees and they will be easier to remove if I change my mind about having a line of cedars in the pasture.
It'll be tough to wrap my head around planting cedars instead of cutting them all down without mercy, so I'm not sure if I'll ever get around to doing something so unconventional.