Sistering Cantilever Balcony Joists
Last Post 23 Aug 2013 02:10 PM by ron Busch. 0 Replies.
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ron Busch
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23 Aug 2013 02:10 PM
    Balcony is 25' wide, 4' deep, 2 X 8 16" On Centre joists. Each joist has varying degrees of dry rot most likely requiring removal of the front 4" of the joist and approx 1" off the top of each. Leaving each joist at 3' 6" extending from the home. I'm looking at sistering a new 3' 6" piece of Pressure Treated 2 X 8 to each joist utizling Premium Grade Construction Adhesive, 1/2" Carriage Bolts (9" on centre (2" from top and bottom of board)) alternating top and bottom each 9" then adding GRK 2 1/2" construction screws above or below each carriage bolt.

    The front of the joists will have a new facia of 2 X 8 PT attached via Simpson Strong Tie Joist Hangers

    Bead of Silicon sealant will be place along top joint between existing Joist and new sister plus a membrane on top of each to minimize or eliminate any water ingress down the road. The new decking will be supported by the new sistered 2 X 8 at a minimum, via the carriage bolts, screws & adhesive to the exisiting now modified to approx 2 x 7 joists.

    Is that overkill? or am I in the ball park? Perfect world would be to pull the existing joists completely or sister the full length but that is cost prohibitive at the moment.