Morning all, quick reality check in case what I plan to do will destroy my walls.
Setup: existing rafters 2×6 @ 22″oc, 16′ (yup you read that right) on 8/12 roof. Ceiling joists 2×6 @ 16″oc. Everything toe-nailed into 4×4 top plate. CJs not tied directly to rafters. Rafters are showing stress around the toe-nails
Plan, in preparation for insulating roof deck: 12′ 2×6 sisters on rafters to stiffen them up. For strengthening connections to top plate, my plan is Simpson hurricane ties, preferably H10 (custom-sized) if it goes high enough, otherwise 2 H2.5A connectors. Each H10 would require 8 8dx1.5 nails into top plate, each H2.5A would require 5 8dx2.5 (that’s 10 nails per rafter).
Now the tricky part: the finished room below (ceiling down) has original plaster walls that I don’t want to lose. Plan is to use angle grinder and diamond blade to cut the plaster about 2-1/2″ down, remove plaster and lath (plaster already badly damaged near the top from previous remuddling), attach hurricane ties to top plate, fur out, new ceiling, then molding to cover the dirty deed.
Is this scheme (a) SOP (b) utterly insane (c) somewhere in between?
Thanks for any advice.