Do I need a roof beam?

[Bob Kocourek]

I plan on building a 24' x 30' garage in a heavy snow load (50 psf) area. It will be a simple gable roof with the peak on the 30' axis; rafters will be 2x10's on 24 inch o.c., 6/12 pitch. The rafters will seat on a five foot high side wall, with 2x6 collar ties at about 7 1/2' from the floor, with a 2x12 ridge board. My question is: will this be adequately strong to resist spreading those 5' sidewalls, or will I need to install a glue lam beam (of yet undetermined dimension) at the ridge? If I need a glue lam, any idea what size would be required? I can post it at the 18'/12' point to lessen the span.

[Don_P]

Each pair of rafters spans 30'? Sorry I'm unclear there.

To answer another way the rafter ties cannot be raised more than 1/3 the distance from plate to top of ridge and they are derated in allowable span as they are lifted.

Pardon my asking, why such a low ceiling? A typical garage door is going to have real trouble.