Do not replace your chicken wire, it will keep chickens and chicks in. But do reinforce it. I have mine reinforced with miscellaneous woven wire on the out side of the chicken wire. What I could find cheap.
I have a small coop, it is only for roosting and laying eggs. Works fine. Mine spend the day outside, sometimes in a run, sometimes free range. In my opinion you must shut your hens up very shortly after dark, I have lost many hens in the early evening, after dark. If I do not think I am going to be home before dark, I leave mine in the coop/run combination.
Put in a roost or an object that is off the ground so that there are multiple levels in your run, A large box will work. Also determine the direction of your prevailing wind, and block that off so they can get out of the wind, a plastic tote laid on it's side will work fine for three hens. Mine are outside in very very cold weather and do fine.
Also, if you have only 3 hens, which should keep you in more than enough eggs unless you have a large family, you need a smaller coop, so as to heat it with body heat, so don't worry about your coop size.
mrsK
I have a small coop, it is only for roosting and laying eggs. Works fine. Mine spend the day outside, sometimes in a run, sometimes free range. In my opinion you must shut your hens up very shortly after dark, I have lost many hens in the early evening, after dark. If I do not think I am going to be home before dark, I leave mine in the coop/run combination.
Put in a roost or an object that is off the ground so that there are multiple levels in your run, A large box will work. Also determine the direction of your prevailing wind, and block that off so they can get out of the wind, a plastic tote laid on it's side will work fine for three hens. Mine are outside in very very cold weather and do fine.
Also, if you have only 3 hens, which should keep you in more than enough eggs unless you have a large family, you need a smaller coop, so as to heat it with body heat, so don't worry about your coop size.
mrsK