Snow load -- go brace your coop and run, BEFORE they are flattened

[CityChicker]

This thread is a funny coincidence because this week, for the first time ever, I had a run collapse. Luckily, there were no birds in it and it only collapsed in the center. I'm sure if there were birds in it, they would have survived, but it is a wake up call. I think it was a combination of some shade cloth that was on top of the run (it was a semi-temporary grow out run) and an extremely unusual heavy snow. Reinforce those runs!

 

[Klorinth]

Very nice Pat. I like this kind of thread.

Where I am from in the Mountains we get big dumps of wet snow. HUGE weights.

With that in mind most people put steep angles and use metal roofing to keep as much sliding off as often as possible.

Just don't be standing under the eave when that snow falls off.

 

[Opa]

A friend of mine lost all of his pheasants when the mesh loaded with snow sagged down trapping the birds. So when I built my run I utilized a center pole with 12 rafters go up to it.

And here is what it looked liked last winter. At one point there was 20 inches of snow on top of it.

 

[BarkerChickens]

Thanks Pat and Ridgerunner!! YOu both have such great advice. While I am not worried about our coop (DH and I planned very carefully!). However, I wanted to add a comment regarding Pat's comment regarding the run cover. A portion of our run is corrugated plastic, which held up great to the snow. Another portion is covered with 2"x4" wire fencing with vertical braces. We figured 2"x4" surely would allow snow to fall through. Uh...no.

We got 14" of snow and while it did not collapse completely, it was warped downward.

ETA: Opa, I really like your run! That is a great idea!!

 

[LynneP]

Thanks to others mentioning a similar situation we caught our roof supports before finishing the run, and placed them 1' apart before installing the vinyl roofing- worked like a charm, and I imagine it's possible to add braces or more roof joists even after a run is completed...

 

[Chook-A-Holic]

Great advice and great timing. Even those such as myself that seldom have significant snow or ice, it only takes one storm to destroy all of your hard work.

 

[Barry Natchitoches]

Can this Southern Boy ask a dumb question?


How many inches of snow would endanger a coop's roof?


I mean, will one inch do it, or does it have to be six inches, or twelve, or whatever?


We get very little snow here in Memphis, but every few years we do get a lingering snow storm. The snow usually does not get over three inches or so, though (except for winter of 85, when there was almost a foot of accumulated snow).

 

[Ridgerunner]

How many inches of snow would endanger a coop's roof?

There is no way to answer this since it depends on so many different things. The materials used, style and quality of construction, the position and spacing of supports, type of roofing materials, spacing and span of rafters, connection configuration and connecting materials, slope of the roof, the list goes on and on. And it is not just snow. Our freak ice storm this past winter was worse than any snow we are likely to get. If you used similar building techniques to other similar sized buildings that have been around a while, you are probably OK. If you have any buddies in the construction business, they can probably give you a good idea with a fairly quick look. In Memphis, I'd guess the design snow load is around 20 to 30 pounds per square foot. That is not a tremendous amount if standard building techniques were used. Wind load in your thunderstorms is probably more.

 

[patandchickens]

Quote:
How long is a piece of string?

We get very little snow here in Memphis, but every few years we do get a lingering snow storm. The snow usually does not get over three inches or so, though (except for winter of 85, when there was almost a foot of accumulated snow).

That's the thing, what tends to matter is not just an *average* winter or snowfall, it's what you *occasionally* get. Unless you just don't mind having your structure flattened. But to me, a) because there are animals in it and b) because it sucks to have to replace broken materials and then rebuild the whole thing, it is usually worth planning for the "reasonably foreseeable unusual occurrance", not just what you might get away with in any given winter.

Also your snow is often *wet* snow, either cuz it fell while fairly warm or cuz it fell then got rained into. So, three inches of snow in Memphis is not quite like three inches of snow high in the Rockies.

While I am not going to disagree with Ridgerunner about 'snow load probably comparable to wind load' I would like to point out that this does NOT mean that just cuz your coop has survived a bunch of hard windstorms it will necessarily be fine for snow too. First, because the direction of loading may be different depending how your coop is built, but mostly because a wire mesh run top does not have much wind load but *can* have quite a solid chunk o' snow load on it.

I would suggest that you probably want whatever rafter- or purlin-type thingies are supporting your roof or run top to be spaced *no further than* 24" o.c. for most materials/designs; 16" would be better for really floppy things like Palruf (pvc plastic roofing). Otherwise, in the absence of specific info about local snow load specs or your coop structure, I am going to punt back to my original formula of "either design it the same as other ones that have stood for many years in your area, or beef it up as much as you can get up the enthusiasm for"

It really does not HURT to have a few extra crossbraces or props or whatever, and it really is the PITS to have something damaged or destroyed and think "oh yeah, I'd *thought* about beefing that up..."

Good luck, have fun,

Pat​

 

[ColoradoMike]

I finally got around to uploading the pics from my camera. I'm pleased with the performance of our coop after our first significant snow of the season. We 'officially' got 20" out of this storm, but I don't think it was quite that deep on the coop roof. It did start as rain, so the base of the snow was pretty wet and heavy. The chickens didn't seem too bothered by it at all, but it wasn't terribly windy, so I think that was a big factor. I'm going to get windbreaks of some sort (straw bales I think) for the winter - we can get some wicked winds around here. The snow didn't last for more than 4 or 5 days - the past two days we've been in the 70s.

I love Colorado.