i just bought a really old house which had been placed on a foundation about 50 years ago. The Northeast corner looks like a 10 by 10 or a squared log which runs along the foundation. the corner beam that runs vertically is about as large. I was told the joists underneath are huge tree timbers. This corner is rotted out by about a foot on the vertical beam and the horizontal beam. How do i fix it? do i cut out the corner and replace just the rotted area with chunks of wood? or is there any hope? thanks for any help you can give me.