i would like to install a deck on the rear of a brick and cinder block twin home. to get the ledger board at the correct height for the door i had to attach it to a pair of metal channels that are bolted together with 1 inch bolts 3 places over 14′ span that form a header over a garage and entrance door. the outer beam was drilled and tapped w/ 3/8-16 holes in 10 places . the ledger board extended 2′ past the header and was attached 1/2 “red head ” studs into brick. my question is this, when i pry between the brick and the ledger in the areas between the 1 inch bolts i can flex the channel about an 1/8 inch. is it nesessary to drill through both channel beams and the first floor joist in these areas and attach them together w/ threaded rod. i know this is hard to determine without seeing it but any input would be helpful