Pugsabi
Free Ranging
It’s not lead paint, and I’m not sanding in the run. It’s needs to be repainted because of the water damage to the wood and peeling paint that’s already on it.
And that side will be left open, that’s the chicken “door”
Do a test patch to see what method you like more. If the top is super heavy I wouldn't bother to do any other kind of roofing materials.