Our deck is approximately 25 years old. Original decking (and structure) is all pressure treated lumber. The decking needs to be replaced. Here's the challenge. The deck is approximately 30' x 12', with one part (10'x10') covered by a screened enclosure. I believe that this enclosure was installed after the deck was built. The lower part of the enclosure is 2x4 wall covered in shingles, the upper is screened, with vertical supports holding up the roof structure. This is all attached to the house... The decking in the screened area is okay and does not have to be replaced. So here's my question. I suspect that the 2x4 wall is nailed to the decking (and the joist directly underneath). If I try to remove the decking under the wall I'd have to cut all those nails (or screws), and I have no way to reattach without opening up the wall. The obvious alternative is to cut the decking at the base of the wall and sister a new joist to support the end of the new decking. If I use this approach, I'm not sure how to trim it to cover the end of all those planks (purely a cosmetic question...) I've included a photo of the base of the 2x4 wall and decking area. The house wall is to the left of the photo, perpendicular to this wall, and is shingled in matching cedar. Other approaches to consider? Thoughts appreciated!