Best 'vents' for hay barn roof?

Should preface this with the fact it will be a metal storage building (like the prefab/garage / carport ones).

It will have the condensation preventing flocking added inside roof–

But I know? I would want air ventilation especially at roof---- what kind do you find will allow air out? but not rain/leaks in!?

turbine?

ridge vents & eave vents?

TIA!

I think this is good info
http://www.progressiveforage.com/forage-production/harvest-and-storage/storage-of-small-square-bales

Or check Extension websites for info on storage.

Hippolyta that was a great article THANKS! not sure? if the explained suggestion is one I can get as optional on the type pre fab carport types but I’ll show the contractor!
Anyone else like any certain types?

Interesting article. I’m still not sure what I should do, or what you do for a carport?
For example, I have hay in an 18’ x 24’ garage (cement floor and walls, hay on pallets, has a shingle roof) and there is zero roof venting. No ridge vent as there is no way to have a soffit (roof ends at sidewall).
I had thought about installing those end wall vents, but I don’t know if they do much? I’m getting a garage door installed (tarp if it rains now). I was just planning on leaving the garage door open all the time, unless there is weather.

I have a metal building already. It had no ridge vents or anything.

Before storing hay in there, I added some louvered vents down in the end of the building near the hay storage, and may need to add a powered fan (dustproof of course) to encourage circulation since it does get hot and muggy in there. A ridge vent could allow birds, critters, and rain in so I’m not necessarily suggesting one is necessary.

But our only evidence of mold came from the moist floor. I strongly recommend buying a bunch of pallets and 7/16" OSB plywood and making a raised deck to avoid stacking the hay on the floor. It helps if the pallets are the same length/width/height so that they make a nice level deck. OSB may be better than premium plywood, as the lack of veneer gives you better grip to walk on.

Farm Tek has lots, but the prices are high. Maybe find what you need and show the contractor so he can get it local/cheaper?