I recently purchased a 100+ year old home in Connecticut. Attached to the rear of the home is a 18x20 addition. I believe the space was originally a garage that was later coverted into an in-law apt. After demoing the room, I noticed that the roof is framed with full dimensional 2x4's, 24"OC. The roof is pitched quite low and I'm concerned about snow load. Suggestions? My thought is to sister 2x8's.