Converting a galvanised tin shed to a coop - advice needed on ventilation

[Achelois]

We bought a second-hand tin shed cheaply for our new coop and have built it up onto a raised wooden floor with a hatch for cleaning. It's all going well so far but we need to sort out some ventilation before we paint it. We've put roosts around two sides - one side is going to have nest boxes, and above the perches and nest boxes we're going to have broody boxes (just a couple) and space for new chicks.

I realise that we need heaps and heaps of ventilation, but I'm unsure of how to do it without getting driving rain inside and I'd like any flashing/covering to still look nice. I have an angle grinder and can cut vertical slots in the tin and then cover with wire, but what then?

The shed measures about 2m x 2.9m (6.5 x 9.5ft) and we'll have a dozen permanent chickens in there, but we raise babies as well, so over summer it's not unusual to have 20 or so with the younger ones of roosting age there. We live in a fairly warm, dry climate in the Southern Hemisphere - it doesn't go far below zero degrees C overnight in winter and never snows, but it can get into the early 30s celsius in summer, so it's heat I'm most concerned about - although they'll be roaming free during the day.

Thoughts? I'd be really grateful if anyone has photos they'd like to share of a converted tin shed!

 

[PapaChaz]

go to your local building supply house and look at the foundation vent covers, they're made to allow airflow through but the slots are angled so that rain won't go in, and runs off the outside. I'd make sure to set it up if not all four sides, at least opposite sides for cross flow, and since heat rises, put them as high on the sides at you can.

You might even want to put them slightly higher on one side than the other to set up a "draw" as the heat escapes the higher one, it will draw fresh air in the other side

 

[Achelois]

Thanks for the suggestion. I've looked at our local hardware store (which is fairly small) and they only had small louvres which were expensive and didn't seem to offer much actual ventilation space - there was more metal than there were holes. I don't think that those were foundation vents though; they seemed too small. I am constrained a bit though as the shed is made up of corrugated panels, so I have to work within that and it'll probably be a home-made solution.

I'm just concerned after reading this article that it's going to be difficult to provide enough ventilation and still keep it rain proof - I worked out that I'll need at least half a square metre/6 sq ft of ventilation - and that's a bare minimum figure which doesn't really allow for our summer heat. UNLESS - if I completely remove the tops of the doors, make an awning and then just have a couple of smaller vents at the back - that could work without affecting the structural integrity?

 

[Ridgerunner]

Your link did not work. It just sent me back to this thread.

30 C = 86 F. You will need decent ventilation. Some of the need for ventilation is in the winter to get rid of excess moisture in really cold damp climates. 0 C does not qualify as all that cold. You need to get rid of ammonia too but since it is lighter than air, all you need is a hole up high. It does not take a huge hole to get rid of ammonia. Gravity provides the energy to get it moving.

Does that article take into account how hot or cold or wet or dry your climate is? Does it take into account whether you are in the shade or full sun? Did it consider building materials? Does it take into account what kinds of ventilation you are using and where they are located on the building? Or does it throw out a magic number that will work for every chicken coop in the whole wide world regardless of any of these things? It’s possible that number is not fine-tuned to your specific situation.

A metal building is going to heat up in the sun. I strongly suggest you do not put your nests on the sunny sides. For you that means avoid the north and west sides. Nests in a metal building on the sunny side can become ovens. On the cool side it’s not that big a deal, but I still like an opening up high so heat can escape. Hot air rises. Take advantage of that. Another option is to somehow insulate the hot wall. A sheet of plywood between that metal wall and the nests would make a world of difference. I consider your nests your biggest danger area.

I agree heat is your biggest risk. Your chickens should easily be able to take the coldest you climate can throw at them as long as a strong wind is not blowing directly on them. One problem you have is that the metal will get hot in the direct sun. It can radiate a lot of heat. I modified an existing shed for my coop and I have a metal wall on the west side. It gets really hot in summer and cold in winter. My roosts are on that side and my chickens do OK in colder and warmer temperatures than you have. Mine is not insulated.

Structural integrity can be a problem. Normally I’d suggest a roof vent or cupola. Since hot air rises those can move a lot of hot air out of the coop if you have an opening down lower. But there is a good chance your building would not be able to support that, especially in a strong wind. I doubt that your building has a ridge vent. I don’t see a lot of overhang with your roof either. A very simple way of providing a lot of ventilation is to leave the top few inches open under an overhang and cover that with wire to keep predators out. Doesn’t look like that is an option for you.

I’m going to leave it up to you to make it pretty. What I suggest is that you cut some fair sized holes up as high as you can and frame those holes in with wood. Put one strip of wood on each side of the metal and screw them together to clamp the metal in between. Clamping the metal like that will increase the structural integrity and give you something to attach to. You can use 1”x3”, 1”x4”, 2”x4”, or something else, whatever makes you happy and is easy for you to work with. Cover that with wire to keep predators out and fashion an awning or use louvers to keep water out. That’s for winter.

For summer do the same thing but down low. In the summer a breeze hitting them on the roosts might feel good. For your awning hinge it at the top so you can just let if fall down and block the opening in really cold weather. Since hot air rises, put this on the shady side so the air going in is cooler. The heat of the sun will provide the energy to move a lot of air. Another trick is to cut out a window at roost level or a little below and just cover that with wire for summer. But have a piece of Plexiglas cut and ready to put over that window in winter to block the wind but still allow light in. A window is nice and the chickens often like to roost near a window. Next to my window is the prime roosting spot.

When you paint this do not paint it a dark color that absorbs heat. Paint it a light color that reflects the heat.

I’m not going to give you any magic numbers as to how many square feet of ventilation you need. I don’t know what will work for you. I understand people just starting out needing some guidelines and if that is the article I think it is, those guidelines were given as a starting point. It’s a really good article. The number given is something that is intended to make every coop in the world pretty safe. That means it is overkill for most coops. That’s the way the guidelines work since you cannot cover every possible possibility with just one number. In any climate it is hard to give too much ventilation as long as you keep a direct wind from hitting them in the coldest parts of winter. After all, their natural roosting spot is in a tree which has great ventilation.

Good luck!