So, once upon a time the sprinkler got aimed towards the French door. I noticed because the bottom of the door didn't look so good. After fixing the sprinkler I put off fixing the door for a long time. Recently I had a termite inspector note the damage to the door and the trim board next to it. So Monday, my first day off for the summer, I decided to try to repair the door. The rot was below the bottom glass. After some research I took down the door and replaced the unsavable section and repaired the rest. Yesterday, the door is about finished and I'm waiting for the primer to dry and decided to repair the trim board adjacent to the door. After removing some rotted wood I see more rotted wood, and then more rotted wood and then more . . . Get the picture? At this point I have cut the bottom few inches off the trim board and the bottom few inches of the side of the door jamb, pulled up the metal threshold and made a visit to the scary crawl space underneath. The subfloor had a rotted spot that my hand went through, directly under the end of the threshold. The top 2 inches of the rim joist is toast for about 5". The door jamb is rotted at the bottom. OMG, good thing it's only the first day of summer. I can't quite see how the jack stud looks yet, though I suspect the bottom is rotted. Outside the door is a deck. Between the deck and the house is siding, plywood and a ledger board. The plywood and siding are rotted in the same section. The siding turned into virtual dirt and kept the whole spot nice and moist. Seems the water entered through the hole in the trim board and just stewed in there under the threshold and ran under the metal flashing to the siding and plywood exterior. The doors lead to the dining room with ceramic tile over backerboard, the part under the tile seems fine, but the exposed strip of subfloor isn't. The floor joists run parallel with the rim joist. Nothing seems to be sagging, no cracks in the drywall. Do I have to take the whole door jamb apart to expose the jack stud? Can the bottom of it be replaced without tearing the whole thing out? I'm open for suggestions. :help: Next step, try to post a pic, stay tuned.