The one version I saw for that was wire on the inside to protect the insulation.

Even putting 1/2 inch on the roof and outside will help both the heat and cold.

Providing you protect the inside from pecking.

I have the walls in the coop insulated with roll insulation and covered with OSB board and the floors with green plywood and the seams are tarred, even with 2 heat lamps going and it being 60 degrees in the coop the roof snow does not melt. I trimmed the bottom of the walls with a wood "mop board" to keep the OSB from getting wet when the wood flakes pick up moisture from them tracking in and out.

or I had a stack of 2" pink board behind one of the sheds, yesterday I was back there and a foot or two is gone up as high as the hens can reach. )
And they have worked up behind the tin on another building as far as their necks are long.

Have to be careful with heat lamps. Just a few days ago a neighbor lost his whole flock due to fire. Figured it was caused by the headlamp.

I used 2" and overlaid it.

A heat lamp won't go poof like a regular bulb when damaged it will toss sparks for a long time when broke at the stem even. Almost lost the brooder house a few years back to a bulb the chicks knocked down. Just made this guard out of some rod material I had in the shop, I sleep better that way.

Most people over think it. No need for insulation, and no need for a light at all except to increase winter time egg production. When I do use a light, it's just a 25 watt bulb. I can buy eggs for less than it costs to just burn a heat lamp bulb every night.
Having both heat and insulation is actually just inviting pneumonia.

How cold does it get in Ohio?

It gets below zero several times/winter. This year had sub zero temps for many days in a row, over a week in one stretch if I recall.

I wasn't going to mention that. I have two screened "windows" that stay uncovered down to about 10F,and no insulation. Birds need ventilation much more than heat. The light is on when I'm in there or if they are cooped up for bad weather, it is so they can see to eat. In a properly sized coop the birds will heat themselves.

I keep fresh wood chips and my coop is vented, I plug the roof vent in the winter but the little door and the door screen is cracked a bit for ventilation. -16 the other morning I think a heat lamp is warranted if the wind is out of the East it rarely is the little door gets shut. My thermostat has a humidity gauge on it also with fresh chips, the venting of the coop and heat lamps I don't have much for problems.

Lugnut, What kind of chickens laid the three redish brown eggs and the green looking one? My wife is getting bored with just light brown eggs.

The reddish brown ones, some speckled, some not, were from our Welsummers.

The green ones were from our Chanteclers and Ameraucanas (Easter Eggers).

Thanks

Lots of ideas to choose from.

Sounds like some working project to start.

Thanks again.