Hey guys, gpt a question for ya. We have a cabin that needs roofing and are going to go with metal. Had a few bids but they differ in the installation. One will put down felt over the old shingles, nail down 1x4 strips and install the tin on top. They say this is for air flow? The other guy says he will lay felt over the shingles and just screw down the tin on top, no 1x4’s. Everyone I ask has an opinion and I’ve heard of doing it both ways, what do y’all think?