My chicken coops have always had metal roofs, and now I’m trying out metal siding, on the grounds that I want anything I build to last 20 years without maintenance, and the exterior plywood I’ve been using doesn’t deliver that.
[Update: Seven years after writing this blog post, the corrugated metal walls are holding up well. Seven years is long enough for plywood walls to start falling to pieces, but the metal walls are holding up well, with only a bit of rust here and there.]
Does Metal Promote Condensation and Wetness?
People will tell you that metal siding sweats, because of condensation. This is true if the inside of the house is warmer than the outside, since moisture from the warm house will condense on the cold walls and ceiling. But it’s not about metal vs. wood, since condensation forms on any kind of roof or wall, no matter what it’s made of. In marginal cases, it’s more visible on metal because it’s 100% non-absorbent.
A Fresh-Air House is a Dry House
But you can dodge the problem with a fresh-air poultry house. If you add enough ventilation, the inside of the house is just as cold as the outside, and you get no condensation. My metal roofs don’t have condensation unless there’s snow on the roof and temperatures are above freezing. The rest of the time, my highly ventilated houses have dry ceilings and walls.
This is one of the main points of Fresh-Air Poultry Houses, the chicken-coop book I’ve republished (check out the sample chapter if you haven’t already). It focuses on the advantage of well-ventilated houses, a concept that still needs to be repeated constantly today. You won’t read anything about metal walls or roofs in this book, since it predates their use, but it’s a treasure trove in other ways.
You can also prevent condensation with insulation, but I don’t do that.
Can you really prevent damp chicken houses through ventilation alone? Well, it works for me, and I live in Oregon, which has a famously wet climate!
Installing Corrugated Sheet Metal Walls
Back to the construction project. In keeping with my other rule of construction (never use a saw when you can buy stuff that’s already the right size), I ignored my existing stock of 10-foot metal roofing and obtained some cheap 8-foot corrugated roofing from Home Depot. My chicken houses are 8×8 feet.
Karen and I banged these sheets onto a couple of sides of a chicken house where the old OSB siding was falling to pieces. We used roofing screws. These are hex drive screws with neoprene washers. We used to use roofing nails, but they pull loose too easily and we hate having roofing panels flapping loose in the breeze! And using power tools instead of a hammer keeps my shoulders and back from seizing up. I bang the screw in a short way with a hammer, then drive it home with a cordless drill.
I’m told that roofing screws have three times the holding power of nails.
These panels went on very quickly, and if they ever rust through (which they will, at the bottom edges anyway, if I allow chicken manure to pile up against them), I can take the screws out and replace them just as easily.
So far, so good. The shiny metal really brightens up the interior of the chicken house, and because it’s non-porous, it provides no place for roost mites to accumulate.
Cheap Roofing is Good Enough
Plain old “ripple metal” (corrugated steel) is less rigid than V-channel roofing, but it’s proven to be stiff enough, even for a house that gets dragged around behind a tractor, which can put all sorts of stresses on it, especially if it gets hung up on holes and bumps along the way. So far, so good. That means that, so far, the cheapest possible corrugated metal has been perfectly adequate.
Watch out for translucent corrugated fiberglass. In my experience, it’s not very strong and becomes increasingly brittle over time. I’m sure it has its uses, but don’t think of it as being structural in the way that plywood and corrugated steel are.
You Don’t Have to Settle for Ugly
Of course, you can build a much prettier house with metal roofing with baked-enamel finishes in designer colors, and you should probably do this if you don’t want a silver house, since it’s hard to get paint to stick to galvanized steel. While I’m always looking for the cheapest, longest-lasting, easiest-to-build designs, there are plenty of other ways of approaching the problem of chicken-coop design.
I Publish Books! Norton Creek Press
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Hi Robert
I read your posts on open air houses and deep litter with interest. However, I am curious how you deal with the rain. It seems that keeping litter dry is the key yet open air shelters don’t control the rain at all. Am I mixed up? Is it all in the design?
To help the bottom of the iron sheets from rusting from chicken manuer build up, I line the bottom two feet of the walls with fibre cement sheet so the chicken manuer is not hard agains the iron rusting it.
We are new to chickens and love them! We are in the process of building a coop (currently using the chicken tractor for 11 hens and 1 rooster with 45 young in a growing area indoors still) We are using metal siding but don’t want condensation either. Can you coat the metal with any type of paint or other spray on insulating type foam that the chickens won’t eat?? Just curious and trying to avoid more plywood but will do what we have to so we can have healthy, happy, productive chickens.
Pam,
My experience is with bare metal siding, which works well. If you have enough ventilation, there’s rarely any condensation on the siding or roofing, except when there’s snow on the roof and the temperature is above freezing.
I’m told that some people have protected foam insulation cheaply by covering it with window screening so the chickens can’t get at it. I haven’t tried this. If you give it a go, let me know how it works out!
HI Robert, I am trying to figure out if a metal coop will work for Colorado. We have extremely cold winters and normal 100 degree summers?
If so, will you please give me some guidance on the ventilation? how I should do it?
Thanks so much.
I’ve always lived within 40 miles of the Pacific Ocean, so I’m no expert about Colorado climates. The thing about metal coops is that the walls and roof will create an enormous amount of condensation whenever it’s colder outside than in. With enough ventilation, this rarely happens, except when there’s snow on the roof and the air temperature is above freezing. This happens maybe one or two days a year in my climate.
In more challenging climates, insulating the roof limits condensation even if ventilation is limited.
For hot weather, cross-ventilation is key, so some kind of major openings in the back as well as the front of the coop are called for. Arranging drafts at floor level is just as good in hot weather as it is bad when brooding baby chicks in the winter.