There are gaps everywhere and I was about to plastic the whole thing, but I keep reading that’s how you end up with frostbite and ammonia. What’s the right balance?
Great question, and you’re already thinking about it the right way — most folks who get into trouble sealed everything tight first and asked questions later.
Here’s the core idea: ventilation and drafts are two different things.
A draft is cold air moving directly across your birds at roost level — that’s what causes frostbite on combs and wattles. A draft is bad.
Ventilation is air exchange up high, near the peak or soffit, that lets moisture and ammonia escape without blowing cold air on the birds below. Ventilation is good, even in January.
So the goal is:
- Seal gaps at bird level and below — walls, corners, anywhere a cold stream of air hits a roosting bird
- Leave or create openings up high — even a few inches along the top of a wall or under the eave on the non-prevailing-wind side
The sniff-and-look test: Stand in the coop at roost height. If you can smell ammonia, your ventilation’s not enough. If you feel a breeze on your face at bird level when it’s windy outside, you’ve got a draft problem.
On the plastic: Nothing wrong with using it to block low gaps — just don’t run it floor to ceiling on all four walls and call it done. Patch the drafty spots, then make sure you’ve got air moving out up top.
One other thing that sneaks people up: deep litter or wet litter generates a lot of moisture. If your bedding is damp, no amount of ventilation fully keeps up. Keep the litter dry and turned and that goes a long way.
What size coop are we talking, and how many birds? That’ll help me get more specific about how much vent area you’re likely looking for.