Large horse barn shed roof construction

[KrisWithaK]

Please pardon my lack of proper framing terminology as I'm by trade a finish carpenter and only getting myself involved in framing in order to help my family's business from falling down ( literally ).

Currently the horse barn has two buildings, one is an indoor riding arena, 60'w x 120'l. The second portion of the building is a large shed style building attached to the long side of the indoor (120'l) by approx 34'w with a roof pitch of 2:12. Anyway, the shed roof building roof has over three layers of rolled asphalt roofing on it, leaks like a waterfall and is going to be torn down for safety reasons (lots of sheathing and rafter rot)

Anyway, I plan on building a matching building with a matching roof pitch. The new building will once again be attached to the highest point possible of the indoor (13'), will be 34' wide, 120' long, and be 8' tall at the low end. The only problem is that there needs to be a continuos 12' aisle down the center of this building, so I cannot put a girder down the center. I can put girders at 10' in from the indoor and 12' in from the low 8' end. This leaves me with three possible rafter lengths, beginning at the indoor a 12' rafter, another 12'rafter to span the aisle, and then a 10' rafter to the exterior 8' wall. FYI roof wil be 60 mil EPDM. I am concerned with the roof and structure because the building is in an open field and we live on Long Island and do get a decent amount of snow every other winter...


My main questions are:

-Should I use 35' TJI's and put girders up at the 10' and 12' areas?

-should I use three rafters in total to reach the 35 roof span and just overlap them on top of a girder? If so, can the tops of these girders be beveled to accept the pitch of the rafter and then just rafter clipped to the girder or should they get birds mouth cuts to lock the building together better?

-should I do a flush double or triple lvl at 10' and 12' areas and just post under that accordingly?

-will I need collar ties from the low end (8') to the high end of the building to keep the roof from wanting to slide and push down on the low end?

I've been trying to come up with a framing plan so I can have framers properly bid on the project. The reason I don't have an engineer yet to answer all these questions is because we need to see if we can afford this new building before we spend 4k plus on an engineer.

Any help or advice would be greatly appreciated.

Best,
Kris

[e hilton]

Have you considered trusses?

[parkwest]

I concur with e hilton!! Talk to your truss manufacturer and find out what he has to offer.

[KrisWithaK]

Trusses would definitely work, just concerned they would eliminate precious loft space needed for hay, feed, etc...

[parkwest]

Talk that over with your truss guy. If they can put bonus rooms over garages with trusses, I bet they can design trusses for a hay loft.

I'm not quite sure what you mean when you say "10' and 12' areas" I suggest you hire local designer to come up with a plan for you.

I suggest raising the pitch so as not to have the same problem with water damage as before.

[KrisWithaK]

Thanks for the helpful suggestions. I am going to look into a truss system.

Best,
Kris

[David Meiland]

I would definitely look at raising the pitch to at least 3:12. Lower than that and you don't have many options for roof cover.

[jimAKAblue]

The new building will once again be attached to the highest point possible of the indoor (13')

What is compelling you to limit the new roof to this 13' benchmark?