Repair part of a beam under the sub-floor?

Question

how so I repair part of a beam under the sub-floor which is rotted from water in the upstairs bathroom. I need to repair it before replacing some sub-flooring

Answer 1

you can "sister" the joists.  Buy lumber that is the same size as the rotten wood and sandwich the rotten wood between the two new pieces.  Make the new cuts of lumber considerably longer (if possible) that the rotted wood and s***w or bolt together.  This is a very simple fix.  Good luck

Answer 2

The best thing to do is to totally replace that beam. Just rip it out and put another one in its place.You can "sister" the joists as described above, but replacing it entirely is best  because it is the strongest and simplest option. And some localities' building codes only allow "full length" sister joists. These are the same size and length as the original joist. Also, if the joist is an engineered I-beam, you must replace the entire joist.

Answer 3

You cannot by code "sister" to an existing joist.  A defective joist must be replaced.  If you have access under the floor, it will be hard, but doable.  If you don't have access to it, you may want to have a contractor come in and replace it for you.  It can be a bear to do.  Hope this helps.