Thanks. I would suggest discussing with your metal roofing supplier. However, if you run horizontal purlins, I really see no need for vents. The horizontal purlins will create a thermal break to help discourage condensation on the inside of the structure. If you want to cross-batten (vertical and then horizontal), then you could think about some sort of eave and ridge vent detail but, otherwise, it will not do much good.
I am building a large barn/workshop. Roof will be insulated/no attic. Everything was cut from my wood mill and the roof decking is 5/8" boards 10-12" in width. I have synthetic underlayment on all ready. Was going to install metal roofing directly to deck but worried about venting/radiation of heat etc. If I install purlins what is the best way to vent drip edge and prevent bugs etc, inside closure strips are solid foam? should I worry about radiant heat, its not my house only a work shop but will be insulated and heated at times. Thanks
