I am finally getting around to installing a new deck on our house. Problem is, I have to tie into a 4x12 beam that holds up the house. One of those beams has about 25% rotted at the top due to an old deck (outside of the house perimeter). I would like to firm up that material as best I can before bolting new beams to it. I had the idea to push some bleach in the rotted portion to try to kill the mold/bacteria or whatever is eating at the wood. Letting that dry for a while and then using some kind of epoxy or filler to sort of fill in the voids. I know this is not a great solution but it is the only thing I have left. I would have to do MAJOR rework to get that beam out and put in something new. The rotted portion is outside of the perimeter of the house so I feel a patch like this would be OK. Does anyone have an opinion about how best to restore what is already there? Thanks in advance for any help.

-Walt