So, you've already built it?I ended up using a different kind of steel roofing that has less places for rats to get in. For the channels above the eaves where a rat could slip in I added rolled up hardware-cloth, held in place with some deck screws:
View attachment 3866926
Along the ridge I was a bit more lazy and just have one or two screws blocking the channel:
View attachment 3866927
The picture makes the gaps look bigger than they are, but I'm still not 100% sure that this will keep out the rats.
Anyone have a good rule of thumb to decide if a gap will fit a rat? A quarter sized gap? Smaller?
Can we see pictures? I love to see finished builds!!