Hello, new around here.
Ive read that AG metal has it’s issues, and many would only consider it for AG buildings. But then there’s allot of people that swear by it… And my buddy has a bunch of it for 1/2 price.
The issues I’m finding are screws backing out due to more than 1/4" of expansion contraction in 10’ in Iowa, and how the horizontal wooden battens don’t ventilate unless you install a grid… A little condensation wont hurt anything imo as long as there is a ventilated vertical air space, which horizontal battens cant provide.
About those two main drawbacks… Ive read Serrated type AB sheet metal screws, combined with stainless steel 18/8 bonded neo EPDM sealing washers is a good way to prevent the screws from backing out. It’s to bad I cant find any roofing screws with good sealing washers that are actually Serrated though! Then doubling the battens to provide good vertical air flow could also give me my missing overhang and soffit vent.
Anyway, Im wondering how the members here feel about AG metal roofs. And if the steps Ive mentioned would give me a good trusted roof for the next 30 years? Or should I use a good class 4 shingle like malarkey legacy or gaf armorshield II?