How To Add Ventilation To A Chicken Coop

While working on a project to convert some of our old workshop building space into a chicken coop, we had to install vents. In fact, they should have been installed when the building was first built or as soon as we bought the house (this building came with it), but I digress.

How can I add ventilation to a chicken coop? If the coop does not have proper ventilation, the easiest way to add ventilation is to install vents. Cut two holes in the walls of the coop, ideally on opposite sides, to fit simple gable vents into and install the vents. Caulk around the vents and the vapour barrier to seal them in place, and add bug netting if need be.

That’s a very simple yet vague answer to a question that demands more detail, so in this article, we’ll discuss how we went ahead to install vents and effectively add ventilation to our workshop-turned-chicken coop.

Of course, these principles will also apply to smaller chicken coops—you don’t have to convert one of your buildings! Note, too, that I’m not a professional carpenter but rather a DIYer. There are certainly multiple methods of adding ventilation to a chicken coop, and I’m here to write about how I did it!

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Why Ventilation Is Important In A Chicken Coop

To begin, ventilation is important in all buildings—it’s why you’ll find gable vents in attics and mechanical air exchange systems in new building codes.

The importance is in the primary role of ventilation: to allow air to flow in and/or out of a space to keep the air within the space relatively fresh and prevent condensation buildup that can lead to mould growth.

As an aside, we noticed this summer that there was blue mould forming on the drywall of the building we’re converting due to the lack of ventilation already. To point out the obvious, fresh air is good for animals, while mould is not so good.

In addition to the humidity of the environment (which was largely to blame for the drywall issues we were having), water will also be released into the air when the chickens breathe or produce waste. This additional humidity can cause mould issues and, in colder months, issues of frostbite.

That’s the first point in why ventilation is so important in a chicken coop. The second major point is that proper ventilation will allow ammonia to escape rather than build up within the coop space. Ammonia is released from the microbial breakdown of the chicken waste and can be dangerous for the chickens’ health, particularly their respiratory systems (it’s also harmful to us). And so ventilation is also critical for keeping ammonia out of the coop, helping to keep your chickens safe!

Ammonia is lighter than air (bringing us back to chemistry class; ammonia weighs 17.03 g/mol, while air, made primarily of nitrogen and oxygen, weighs 28.96 g/mol, assuming standard pressure and temperature). Therefore, vents placed higher will allow ammonia to escape safely without necessarily causing a draft, assuming the vents are also placed above the highest roosting rack.

What Supplies You’ll Need

There are many different strategies to add ventilation to your coop. For instance, you could go the mechanical or even wind turbine routes if you wanted.

If you happen to live somewhere warm, an open window could work fine, but the drafts from windows will be problematic in colder temperatures (we live in a Hardiness Zone of 6a, so it won’t be an option for us in the winter).

However, if you’re interested in a simple installation of vents with no moving parts, here’s what I used. I’ll also comment on what I would use instead, having now completed the project.

• Two gable vents
• Exterior silicone caulking
• Wood screws (#8 – 1″) or nails
• Power drill with appropriate bits
• Circular saw (with higher tooth-count blade if cutting through siding or shingles)
• Handsaw
• Tape measure
• Pencil
• Window screen (optional)

As for the circular saw blade, I had the choice (at my local hardware store) between a 48 and a 140-tooth blade. Since I didn’t want to chew up the siding, I opted for the 140-tooth blade (rated for plastic, vinyl and plywood). After some frustration actually cutting through the plywood, I ultimately had to finish the cuts using a relatively coarse handsaw. Knowing what I know now, I would have chosen the 48-tooth or looked harder for a 60-tooth blade.

I also would have gotten short nails or screws (I used #8 – 1 1/4″ screws) that wouldn’t pierce through the interior of the plywood wall (and therefore would have eliminated the need for grinding the screws down on the inside of the coop — not that the chickens would be flying that high, but just for added safety).

How To Add Vents To A Chicken Coop

Alright, with that out of the way, let’s get into how I added vents to our chicken coop.

First things first, I chose my two opposite walls. Usually, I’d install gable vents on the two opposing sides with the longer distance (let’s call it “length-wise”) since trusses are generally designed to sit across the parallel walls having the shorter distance.

However, in this case, I didn’t want to remove the ceiling drywall and get into the trusses, so I decided to install the vents on the opposing walls “width-wise.” I wanted them directly across from each other, and while the positioning is far from optimized, that meant putting them near the corner of the building.

For reference, here’s a shot from the coop to show the garden shed side of the building (don’t mind the construction mess):

So far, so good. Now that I knew where I wanted them, it was time to measure the cuts and make them.

The vents we went with are 8″ x 8″ (plus the sides that allow us to attach them), so I needed an 8″ x 8″ square on each of the opposite walls.

If you happen to be cutting the vent holes yourself in a building with overhang-style (as opposed to cantilever) eaves, be sure to take into account the roof and soffit to the exterior. It’s critical that we don’t cut through the interior wall only to cut through to the interior of the soffit.

It’s tempting (and ideal), looking from the inside, to cut the vents as high as possible (it’s partly why gable vents are so important). However, we do need to be careful of where we’re cutting through to on the outside.

It’s also important to note here that the vents of a chicken coop should be placed well above the highest perching point if at all possible, especially if you live in a colder climate, as we do.

So, I loosely measured about where I wanted the centre height of the vent to be from the outside, ensuring I was well below the soffit. I then went inside and cut a line a small centre line between two studs at that height. From there, I could measure 4″ to the left and right of the centre cut and know those vertical lines would be cut to make for the 8″ x 8″ vent.

The next task on my list was to clear the cutting area. This may not apply to you, but I have built a garden fence up to the coop/garden shed wall, and I needed to trim a post to make the following measurements and cuts. I did so with my handsaw, shown below:

Once the post was down, I measured out my 8″ width and followed that measurement with my horizontal lines that would make for a comfortable cut with the circular saw.

Again, I’ll note that a fine 140-tooth blade is not recommended for this job. It’s too fine and got caught so regularly that I ended up using my handsaw for the corners. Needless to say, the siding got a bit chewed up, but it wasn’t that bad. I’d suggest a 60-tooth blade for something like this (I have a 7 1/4″ circular saw).

Now to reiterate the difference the soffit makes, consider the following two photos of the exterior and interior of the vent hole:

Alright, so the first vent hole was cut and it was time to install the vent itself. Oftentimes these vents are installed before the siding, but I didn’t quite have the luxury.

Fortunately, the siding is relatively easy to unsnap, especially when it’s cut the way I cut it. So, I separated the siding as much as I needed to, removed the siding nails as required (which had already been ground down in the interior), and carefully shimmied the vent into place before refitting all the siding around it.

I tend to push materials past their breaking point, so I tried to be extra careful with the siding and the plastic vent. Surprisingly, the plastics held up, and I could force things into place more than expected. I reckon it may have been thanks to the hot weather (performing this in the cold may not have gone so well due to the potential increase in brittleness).

Either way, I got everything into place, but unfortunately, I wasn’t able to nail the vent appropriately behind the siding. Instead, I screwed through the siding and the flanges of the vent to secure them in place (not ideal, but it works).

I did the same thing with the opposite-side vent, which was much taller from the exterior (the ground is uneven around the building):

I then applied exterior silicone caulking around the inside and outside edges of the vents to help weatherproof them. Of course, the vents will allow humidity to pass, but the caulking will help keep the rain from getting in and soaking the plywood walls.

Julia put me on to a tip to help with silicone caulking, where I dip my finger in isopropyl alcohol before smoothing out the beads to keep the caulking from sticking to my hands. It works pretty well, and I’d offer that advice to you, too.

And that’s how I went about installing vents in our chicken coop! But as an additional project, we also decided to add a layer of bug screens to help reduce the number of pesky insects entering the coop/garden shed. It’s not that we live in a place where mosquitoes carry terrible diseases, but more than mosquitoes, wasps, and hornets are incredibly annoying.

And so, I grabbed some leftover screens from a few screen kits I put together for the house (I knew holding onto the screens would come in handy). I also assembled my staple gun and some scrap wood for framing.

After cutting the screen to shape (9 1/2″ x 9 1/2″ to allow 3/4″ of screen around the 8″ x 8″ hole), I stapled the screen in place and then nailed the thin wooden strips around it to create a frame and better sealing.

Of course, you can opt to purchase vents with built-in screens. We didn’t, as there were none in stock at our local hardware store, so I added the bug screen after the fact.

There you have it! This is what I did to add ventilation to our chicken coop. As I stated earlier, it’s certainly not the only way to do it, but I figured I’d share this with you in the hopes that it can help you install vents in your coop!