
There are different theories on this and different methods work better in different situations. If you have a properly vented attic, I suggested solid decking, underlayment, and the metal roof. Let me know if you do not have a vented attic and we can discuss options. Your area can be prone to condensation so I took that into consideration with my recommendation.
Sorry about that, comments only post after someone approves them. Really, I would encourage solid decking and underlayment followed by the roofing in your case.
Best and cost effective rarely occupy the same space. Tell us more about the roof/attic design and we can get you pointed in the right direction.
Okay I live in South East Texas.... Going to put a metal roof on my house I am doing all the work. so I am looking for the best cost effective way to install it... It's gonna be r panel....should I put solid decking the an underlayment then screw the tin straight to the decking......I freind said I can put purlins down and put foam between them and not worry about an underlayment.... He said that how he was taught to do it in school. I also plane to insualte the celling joist...and a have a vented Attic.
Its a 56' x20' building. 5/12 pitch......20' of it will be vauleted but in that 20' there be about a foot to the roof. Plan on putting soffit vent all the way down and a ridge vent all the way down...
Did my last comment post
Do you think that that putting the tin straight down to the decking would cause it to rust ....Thank y'all for the advice