Fasten the 12-inch long cleats to the joists after pulling them ... screwed into every joist or cleat they span (minimum of three) with at least two decking screws in each joist.

Q: Our 35-year-old house has a 7-foot cantilevered deck on the top floor -- about 25 feet above ground level. The untreated fir joists feel solid but have large black areas on the sides ...