Re: Old Barn Beams in new construction
Depends on the wood species; if chestnut, or white oak, you do nothing and they will still outlast the house. If red oak or poplar, cap them with a copper roof to let water roll off the top, but rot will probably have already started.
Never apply any sealing coat like epoxy unless you know for certain that the wood is dry to the core, because if it's wet inside it will remain so for a good while. Also, any small checks that form will allow water in as if it were entering a dishpan, furthering any decay. If you did the epoxy thing, I'd recommend drilling some good sized holes in the timbers from underneath so moisture has a way out.
Remove not the ancient landmark, which your fathers have set.