It's not about how high "CAN" they fly, it'd about how high they "WANT" to fly. My full-sized fowl have no problems flying up to my 5' high roosts, including the big rooster. Yet my 4' high electric netting keeps them in. They don't want to fly out, with some exceptions I'll get to.
Chickens like to perch. A common way chickens fly out is they they fly up on a perch just because perching is fun. Who knows which side they will fly down on when they decide to come down If you make the top of your fence look like a good place to perch, say you put a solid rail, they may fly up there to perch. If it is wire where they don't have a good place to land they aren't going to fly up there to perch. Fence posts might look like a good place to perch so the wire needs to go higher than them.
I raise a lot of cockerels with my flock. I used to have a lot of them escape over that 4' high electric netting. What was happening is that when they go through adolescence they sometimes fight. If one was losing a fight and wanted to get away but was trapped against the netting the only way it could get away was to go vertical, fly straight up in a panic. Sometimes they would land outside the netting. They did not know to fly back over.
I had something like that happen to a grown hen once, I think she was trying to get away from an amorous rooster. When I was herding her to a gate to let her back in she flew over the netting to get back with her buddies. That time she "wanted" to fly over the netting so she did.
I found that if I configured my netting with sharp corners the number of escaping cockerels went up. But if my corners were 90 degrees or flatter the number of escapees went down. So when you are building that pen, don't build sharp corners. Square 90 degree corners should be OK.
I also noticed that when I configured that netting with a narrow passage to get to a more open area the number of escapees skyrocketed. Like going from one or two cockerels a week to three a day. There just wasn't enough room in that narrow passage for them to pass each other without fighting.
It doesn't sound like you have cockerels or an amorous rooster. 4' might be plenty in a 14' x 75' run. Sometimes a hen will learn that she can fly out so she does. But with 10 hens on that big of a run you will probably be OK.
Chickens like to perch. A common way chickens fly out is they they fly up on a perch just because perching is fun. Who knows which side they will fly down on when they decide to come down If you make the top of your fence look like a good place to perch, say you put a solid rail, they may fly up there to perch. If it is wire where they don't have a good place to land they aren't going to fly up there to perch. Fence posts might look like a good place to perch so the wire needs to go higher than them.
I raise a lot of cockerels with my flock. I used to have a lot of them escape over that 4' high electric netting. What was happening is that when they go through adolescence they sometimes fight. If one was losing a fight and wanted to get away but was trapped against the netting the only way it could get away was to go vertical, fly straight up in a panic. Sometimes they would land outside the netting. They did not know to fly back over.
I had something like that happen to a grown hen once, I think she was trying to get away from an amorous rooster. When I was herding her to a gate to let her back in she flew over the netting to get back with her buddies. That time she "wanted" to fly over the netting so she did.
I found that if I configured my netting with sharp corners the number of escaping cockerels went up. But if my corners were 90 degrees or flatter the number of escapees went down. So when you are building that pen, don't build sharp corners. Square 90 degree corners should be OK.
I also noticed that when I configured that netting with a narrow passage to get to a more open area the number of escapees skyrocketed. Like going from one or two cockerels a week to three a day. There just wasn't enough room in that narrow passage for them to pass each other without fighting.
It doesn't sound like you have cockerels or an amorous rooster. 4' might be plenty in a 14' x 75' run. Sometimes a hen will learn that she can fly out so she does. But with 10 hens on that big of a run you will probably be OK.
