Metal Roof In Wisconsin Winters - Insulation? Foam caps? Plywood? Or will just purlins do?

[Captain13]

I have a metal roof on my barn lean to. Three side completely open and in the winter, it’s like rain under there in the mornings. I think it’s because of the the floor of the the-to is just bare ground. The barn is on a slab and there is no condensation on the tin roof. I know that doesn’t answer your question….it’s just an observation. To be safe, I would do as suggested above with the OSB, felt then metal roof.

 

[Coopin Is a Habit]

I use commercial rubber roofing. It's very thick. I know you are short on time, but in the future, if you are driving around and see work being done on a large commercial roof, just ask one of the workers if you can get the stuff they are tearing off. They have to pay to dumpster it and have it hauled off, so they are happy to give it to you. If it gets a tiny leak anywhere, they pull the whole roof off and redo all the rubber. Or for any other reason they have to tear into the roof. I have thousands of square feet of it. The stuff lasts forever. You can buy it at the big box stores but it's expensive and I would rather get it free and keep it out of the landfills. Win/win.

Where are you in Wisconsin lol? I'm on the East side of Madison. If you're anywhere close I'll pay you for around 60-80 sq ft. If you don't mind me asking of course. You can always DM me if you want to keep it private too

 

[mowin]

What kind of felt paper are you using? Also, do you use the foam inserts to block off the tops/bottoms so critters don't get underneath? Someone suggested that to me and I'm wondering if others have done the same

Just regular felt paper at the local bix box store.
If you sheath first, the foam inserts are not needed.

 

[Coopin Is a Habit]

Just regular felt paper at the local bix box store.
If you sheath first, the foam inserts are not needed.

Sorry, what do you mean by sheath? Thanks

 

[aart]

Sorry, what do you mean by sheath? Thanks

Roof sheathing, the sheets of wood you put on the rafters.

 

[Coopin Is a Habit]

Roof sheathing, the sheets of wood you put on the rafters.

Thanks Aart!