I live near Boston and there is a lot of heavy, wet snow on my roof - I recently went up into the attic to inspect and sure enough I saw cracks 12-18" long in 3 rafters emanating from the corner of the heelcut where they bear on the top plate, parallel to the rafters. The rafters are REAL 2x6's at 24" c/c (i.e. old framing, not newer nominal stuff) - this house was built at the turn of the last century. My idea was, instead of sistering them, to first lay flat 2x10's over the ceiling joists and screw them into place, then use vertical lengths of 2x10 as "wedges" to try to permanently "jack" the rafters back up and close the cracks - I would either toe-nail the bases of the "jacks" to the flat boards or use joist hangers to hold them in place, and nail or screw the sloped tops of the "jacks" to the underside of the sloped / cracked rafters. The way I see it, this would both prop up the damaged rafters and prevent them from cracking any further. Any comments or suggestions on this course of action? Any help would be appreciated! I am trying to attach a photo but apparently the max. JPG attachment is 100KB!!!