I spent over an hour looking through my own personal photos of roof damage for the raccoon ones. I inspect structures for damage for a living and have been on thousands of roofs (no exaggeration). I couldn't find my own photos and I pulled one from the internet that demonstrated what I was talking about. Let me be perfectly clear in that the condition of the wood plays zero part in a raccoon's ability to breach a house. They don't do it often, and usually when they get that desperate they are looking for a place to have their litter, but it does happen. The cases I've seen it have been perfectly fine building materials.
One case a raccoon chewed through the siding on 3 sides of four different chimneys before realizing that there was an open flue and she climbed down and had her litter in the chimney that the home owner hadn't been using.
A second case a raccoon that breached the home straight through the fiberboard siding into the wall. That is through the siding, through the wall sheathing, then navigated through the insulation down to a void between an interior wall and the crawl space. I have a picture of one of the young raccoons in a live trap on site, but no photos of the damage.
A third case was on house where the raccoons breached straight through the roof right in the middle of the field of shingles. There were no penetrations, walls, flashing, or otherwise. They went straight through the shingle, felt, and decking into the insulation. It was a vaulted ceiling so there was no attic in which to take refuge. They tore two basketball sized holes in the roof, then left when they realized there wasn't room to live.
My point is not to scare people into losing sleep over the possibility of a raccoon breaching their coop, because the chances are low that it will happen, especially if you get rid of them. It doesn't really matter if more come (because they will), what matters is getting them to move on, either to softer targets, or the trash can, before an individual or group is allowed the time to make a breach.
If a coop isn't covered 100% by hardware cloth that is secured like subflooring (every 4" along the perimeter and every 8" in the field) then a raccoon can chew through it, given the time. Will it happen to you? Probably not, but if they can go straight through the side, that little weak spot you think they won't find will be exploited in a heart beat.
All that said, I built my coop just like everyone else did with OSB, fiberboard siding, 2x4's, shingles, and hardware cloth. I'm not worried about it, but I'm also no longer naive about raccoons and remove them when our paths cross.