Insulating a carport closet

I have a 10' X 20' carport closet that I am converting to a small workshop. I want to insulate it properly. The carport has a flat roof that doesn't leak. I plan on putting batten insulation in the walls r13 for 2x4s. and r30 between the 2x10 support beams in the ceiling. Do I need to worry about a vapor barrier creating a problem in the roof since there will be no space between the insulation and the roof decking? I live in southern oklahoma where we have very few days below freezing and it is very hot in summer so I don't even know how much of a problem condensation is in general. Any advice would be appreciated.
Thanks
Marc
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.