Originally Posted by jojo13
If you don't remove all the rot, but sister on both sides with the same size 2X in treated lumber? The rot should have no impact if you use CPES and bolt through with carriage bolts and sandwich the old beam.
Welcome to the site, this beams is still an unkown as far as strength and weight it is carrying, so we don't know if just a few 2xs will be strong enough to do the job and we don't know if the rot has got to the floor joists above it. Sometimes it is better to change out the whole beam.