I have severe dry rot where the post sits on the footer. I would just replace the post but it is approx 25' long and it is the corner post for two stacked decks. So replacing it is not an attractive option.
I estimate I will have to remove about 8" of rotted wood. What method do you recommend for bridging that gap?
A. Lap joint a section of new wood (soaked in cuprinol first).
B. Build up the footer 8" and re-attach the post
C. Is there another option?
One other option you might consider would be to use 2 4 x 4's (or nail 2 2x4's) together to make a "4x4" and put then 6" away from the post on both "corner sides." Then replace the post. Since you are on the corner of two stacked decks (I am assuming a lot of weight), lap jointing is risky unless you are absolutly sure that the rot does not extend up into the center of the post. More than once, over the years, I have replaced both deck and fence posts where there was substantial damage to the interior of a post where the damage looked minimal on the outside.