There are 2 sets of 2x6x12s creating a beam under my 2nd story deck. One set has started to separate on one end. What is the best way to halt the separation and/or repair? Separation covers about 4 ft, maybe 1/4 inch at max. I picked up 2 sets of 1/2 inch bolts, washers, locking washers and nuts. Are there other options, parts needed? If just the bolts, what is the best way to place them?
So, this is improperly nailed together and coming apart. Drill holes on the vertical centerline for your bolts, and assemble them with fender washers and lock-washers and nuts. Use stainless steel or hot galvanized steel hardware.
Space about 2 feet apart, at an experienced guess. Or hire an engineer for not a guess; they would probably advise on improving the beam to post joint as well. Or do one every joist bay above, whatever your joist spacing is (probably less than 2 feet.) Tighten them all gradually, rather than cranking one tight and moving to the next.
As mentioned in a comment by @quill, what appears to be white-sheathed interior NM cable is a code violation for exterior use. Gray-sheathed UF or W-rated wires in conduit are required for outside wiring.
