Diagram complete, now to build

[squadleader]

As Aart mentions, a cattle panel structure is lightweight. The use of heavy beams seems a waste, unless you have no other use for them.

The following is a quote from a FEMA document regarding snow on structures:

"Roof geometry and roofing material influence the tendency of snow to
slide from a roof as follows:
Low slope roofs retain snow more so than pitched roofs. However,
roof pitches as low as 10 degrees have been observed to shed snow.
Steeper roof slopes shed snow more effectively. Thus, greater roof
slopes are common on buildings in the northern States and in
mountainous snow-prone regions.
Roof pitch that exceeds the angle of repose of snow results in snow
sliding; the angle of repose is the maximum angle at which snow
will not slide, approximately a 30 degree roof slope, often referred
to as 6:12 or 7:12. This is not to say that snow on roofs with a
shallower slope will not slide."

It appears from this that certainly you shouldn't consider a slope of less than 10 percent, but instead more ideally, 30 percent or greater, which should shed snow nicely.

In the following sketch, it appears to me, the low sidewall, parallel to the existing barn, is most efficient with a height of 3 feet, as opposed to 5 feet.
It gives 20 percent more floor area, and a 42 percent roof slope, better for shedding snow.

However, if more headroom is the desired goal, then the 5 foot sidewall gives more, but less floor area, and less roof slope.

You're not proposing a traditional hoop configuration, which forces the cattle panel to form an arch.

The addition of a cattle panel structure to an existing frame structure, will naturally produce a shape more similar to these sketches, if properly supported. The shapes in these sketches, only demand a single bend of the cattle panel, that being at the transition into the short side wall.

Will the slope of the existing barn roof shed snow onto the cattle panel structure, ideally not.

I don't know what roofing you propose, but I wouldn't use anything except a bright white 60 mil PVC or TPO sheet roofing(a single sheet of membrane). This is the same membrane used on large commercial buildings roofs, with a typical lifespan of 30 years.

If you use a dark material or clear panels, the chickens will cook. Chickens are much more sensitive to heat than cold.

I like your southern exposure end, leave it as open wire, even in winter, the other three sides must be closed in winter, but open the other seasons. You might consider an eave extending out over the open southern end, up to 3 feet in depth.

With that ventilation plan, you'll be complying with the same principles as the Woods Open Air Houses.

By the way, if anyone doesn't have a grinder, a cheap ($10 or less if I recall) abrasive blade, in a standard skil saw, does a great job of cutting cattle panels, I've even cut them with an abrasive wheel on a cordless drill, although on this project, I can't imagine why you'd be cutting the cattle panels.

The only exception I can think of, is if you can find a way to start at a height greater than 8 feet against the existing barn, then you could consider using an entire 16 foot cattle panel just on the roof span, then perhaps using a cattle panel on its side, along the short wall giving you a 50 inch height on the short wall.

Using the whole 16 feet of the cattle panel on the roof span is useless though, unless you can start at a greater height than 8 feet, otherwise the roof pitch is too shallow for snow. The greater the starting height, the more width of structure you'll be able to acheive, thus perhaps, making use of all 16 feet of the cattle panels length on the roof span.

This should give you some things to think about. Take a look at the drawings and see what suits you best! Good luck!

 

[Ruralhideaway]

As Aart mentions, a cattle panel structure is lightweight. The use of heavy beams seems a waste, unless you have no other use for them.

The following is a quote from a FEMA document regarding snow on structures:

"Roof geometry and roofing material influence the tendency of snow to
slide from a roof as follows:
Low slope roofs retain snow more so than pitched roofs. However,
roof pitches as low as 10 degrees have been observed to shed snow.
Steeper roof slopes shed snow more effectively. Thus, greater roof
slopes are common on buildings in the northern States and in
mountainous snow-prone regions.
Roof pitch that exceeds the angle of repose of snow results in snow
sliding; the angle of repose is the maximum angle at which snow
will not slide, approximately a 30 degree roof slope, often referred
to as 6:12 or 7:12. This is not to say that snow on roofs with a
shallower slope will not slide."

It appears from this that certainly you shouldn't consider a slope of less than 10 percent, but instead more ideally, 30 percent or greater, which should shed snow nicely.

In the following sketch, it appears to me, the low sidewall, parallel to the existing barn, is most efficient with a height of 3 feet, as opposed to 5 feet.
It gives 20 percent more floor area, and a 42 percent roof slope, better for shedding snow.

However, if more headroom is the desired goal, then the 5 foot sidewall gives more, but less floor area, and less roof slope.

View attachment 1264393

View attachment 1264400
You're not proposing a traditional hoop configuration, whichwforces the cattle panel to form an arch. The addition of a cattle panel structure to an existing frame structure, will naturally produce a shape more similar to these sketches if properly supported. The shapes in these sketches, only demand a single bend of the cattle panel, that being at the transition into the short side wall.

Will the slope of the existing barn roof shed snow onto the cattle panel structure, ideally not.

I don't know what roofing you propose, but I wouldn't use anything except a bright white 60 mil PVC or TPO sheet roofing(a single sheet of membrane). This is the same membrane used on large commercial buildings roofs, with a typical lifespan of 30 years.

If you use a dark material or clear panels, the chickens will cook. Chickens are much more sensitive to heat than cold.

I like your southern exposure end, leave it as open wire, even in winter, the other three sides must be closed in winter, but open the other seasons.

With that ventilation plan, you'll be complying with the same principles as the Woods Open Air Houses.

Take a look at the drawings and see what suits you best! Good luck!

Lots to absorb there. Are you saying that it's possible to use these panels in a straight configuration rather than arched? I've considered that but no precedent.

But first, the actual coop already exists, I'm not sure if that was really clear from my original post. It's a nearly flat roofed structure off the side of the barn. The minor pitch slopes down to the south. It does not shed snow and nearly collapsed last year. It's been jacked up and reinforced. Needs reroofed within a couple years. But it's stood for many more years than I've been here, was plenty old 17 years ago when I moved in.

I'm going to add the half hoop strictly to be winter run space. Winters here are extreme, sometimes there's 4 feet of snow there and the winds come from every direction. Last week I saw wind driven sleet from the south. Another day it snowed into my ventilation from the north.

I'll open both ends and maybe add shade cloth in summer although no one will be confined in there. That will help shade things even in the coop in the quite hot(high 80s to low 90s) summers as well.
Here's the coop.

Outside, north end. Pardon the mess it got cold fast had to get those panels up quick.

 

[squadleader]

You're right, that was my mistake, I didn't understand your drawing, but I don't think it makes much difference.

It's very good news that the existing roof won't shed snow onto the new structure.

You have harsh winters, so a three foot eave on the open south face of wire would be nice to keep out blowing precipitation.

Those sketches I did are to scale. With all your snow the steeper, wider deside sounds better, unless your use of the space demands more head room. You'll have to make that call.

Do not use clear or a dark roof. I already made that mistake last summer, I was forced to paint the PVC membrane white, and I didn't do my research, and used a paint that didn't adhere.

Before I painted it bright white, the black membrane got so hot, I couldn't hold my hand on it.

The good news is the roof membrane is very smooth, which will help with shedding snow, especially with a 42 percent slope.

In my sketches you'll notice I'm supporting the cattle panel every 24 inches with a 2x6 running the 16 foot length of this structure.

 

[Ruralhideaway]

Considering this. Thanks for the drawings they are clear. Very interesting idea.

My roofing plan has been poly carb roofing panels. I bought a stack for 8 bucks each in transparent smoke. These will be good to have in any case. I'm interested in the pvc or tpo membrane material. Got a source? Quick Google search only found wholesalers, no pricing. Ha, speaking of that, I still haven't found a local source for sulphur to add to the dust bath!

 

[squadleader]

I think Tractor Supply has sulfur, but I'm not sure. My local feed and seed is where I got my 10 pound bag of sulfur. I did see it on Amazon before I went into town and got it locally.

The PVC or TPO sheet is something that you can get at a roofing supply house, the only issue is you're looking for less than a roll, which is how most roofing contractors would buy it.

You need to finalize your plan first, so you'll know what size sheet you want, you do not want to be trying to seam two pieces together, you don't have enough experience.

Hopefully, you can find an outfit that will sell you a piece the size you want, if there's any seaming to be done, let that be their job.

You'll only be using it on the roof, not the sides, or ends. Leave the sides and ends open, and just close them in the winter, with those panels you bought, except of course the south end, which is always open to provide proper ventilation.

 

[aart]

@squadleader OP is using the panels as structure to avoid building wood framing.

As Aart mentions, a cattle panel structure is lightweight. The use of heavy beams seems a waste, unless you have no other use for them.

I think the 'beams' will be used mostly as posts to support the panel spans during snow load.
One might be attached as a pseudo 'header' to barn and attach panels to.
Roof rake has been discussed as we in the snow belts are very familiar with them,
you can't build everything with a steep enough pitch to shed snow 'automatically'....
....just as you can't build every coop to embrace an effective air cushion.

I just cleared a foot of snow off of an 8 wide x 6 tall tarped hoop...tarp is pretty slick, snow still stuck and built up.

 

[squadleader]

Good points Aart, I just didn't want her to create a microwave for the chickens.

In any event, because of the low sloped roof, at least she'll be able to get to the roof of whatever she builds, with something with a long handle, that she can use to help the snow get off the roof.

Steeper has got be better for snow load, unless you design heavy enough to actually carry that weight, which is substantial, as you're pointing out.

In a perfect world we all would all just call a carpenter, and have a proper structure built to carry the load. But that's not what happens in real life.

It's nice though, there's folks like you, willing to share knowledge and experiance, when we're trying to figure out a less expensive, or do it ourselves way, to accomplish a building goal, even if we know we're making structural compromises to get the space.

If she uses those clear panels for roofing, I'd make sure at least, the summer shade tarp is white. That'll help a lot with heat, probably no more money, and a cooler tarp probably will also last longer, by reflecting the UV rays off.

 

[Ruralhideaway]

Also them even being in that structure will be optional in the summer, it'll be within the whole run area(dashed line).

You guys are the best for helping me, new innovative ideas come up everything's I ask dumb questions.

Can anyone comment quick on this https://www.backyardchickens.com/threads/need-quickie-advice-building-now.1221587/ before I start screwing this run to the wall?

 

[lazy gardener]

Putting polycarb panels with the corrugations going horizontally will tend to hold the snow, and it won't slide off at all. On the other hand, it's very easy for me to use the bristle end of a push broom to tunk the underside of a tarped CP structure, and the snow load just slides off.

 

[aart]

Putting polycarb panels with the corrugations going horizontally will tend to hold the snow, and it won't slide off at all.

That's true, more reason for the roof rake to get most of it off.