Barn remodel with metal roof

[Harkon]

Hi there!

Thank y'all for taking the time to read my post and hopefully sharing your thoughts.

I am in the process of remodeling my barn into a living/work space. It's a two story building and downstairs is done and turned out so great that I wanna do upstairs now, too.
It has a metal roof, soffits on side, ridge vent on top. 900 sqft.
NO wood between Metal and attic. Just bare metal sheets on 2x6 rafters.
The "attic" will be super small and not high at all. The highest place between drywall ceiling and ridge vent/top of the roof will be around 2-3 feet.

I installed extra 2x4 to hang drywall, so there will be some sort of "attic" space between the drywall and the roof at least towards the middle of the roof/room.
I was thinking to spray foam a little bit to the metal directly (already have two foam kits (Vega Bond V600 Closed Cell Spray Foam Fast Rise 600 Board Feet Kit)
in order to add some R - Value and to fight condensation. (and to seal the roof against leaks)

And then put regular fiberglass insulation between the extra 2x4s / above the drywall ceiling. So that would create some extra "attic"space towards the middle of the roof/room.

So, I am wondering basically two things:

a) will the foam be a waste as it does NOT add any insulation value as there are open soffits and ridge vent (ridge vent will be with these foam things in the shape of the metal rood to keep put critters and insects)

b) what are the alternatives?

Thanks!

 

[Snoonyb]

Welcome.
Well 1st of all, 2X4's on the flat, have no structural strength, so your ceiling, without any storage above, will be bowed.

Were it I, I would double the 2X6's your 2X4's are attached too, rotate the 2X4's 90 degrees and reinstall, with a doubler on each side of the access opening.

I think that installing foam to the underside of metal roofing, to prevent leaks, would likely hide the source of the leak, as water will travel to any opportune location, to exit.

 

[Harkon]

Hi Snoonyb,

Thanks for your reply.

What exactly do you mean with "a doubler on each side of the access opening" ?

Thanks!

 

[Snoonyb]

While not specifically required by code, I always use doublers, because inevitably, folks will overload when accessing.

https://eco-buildingproducts.com/sealin-hatch/framing-for-your-attic-access/

 

[Harkon]

Oh, I might not have been clear about that. There will be no access point. The will be no storage whatsoever in the attic. There is no space for anything. The most it will be around 2 feet between the ceiling at roof

 

[Snoonyb]

Nope, I made an assumption that attic space is generally followed by storage.