hello-

a friend wants to finish out the unfinished attic in his 1880s Chicago Foursquare. the floor structure is 2x6s- old, hard, 6″ deep 2x6s that hardly flex, and that’s without a membrane. i haven’t yet explored if there’s a way to avoid having to sister or do a new floor system there. but since raising the floor will shrink the useable space significantly, i’d like to explore that option.

if i DO have to augment the floor structure, the next challenge is putting the new floor on the walls below: the roof rafters are birdmouthed on the edge of the top plate of the 2nd floor walls. so is sistering my only option? doesn’t seem like i could stand up a new trusjoist or anything on the top plates- no room… is there a standard/easy way this problem is dealt with- shy of taking off the roof? help! thanks.