Much of fine woodworking involves making and correcting mistakes, as well as understanding why something may have failed. I've disassembled 300 year old furniture, glued it back together, repaired dry rot, fixed countless items, put up walls and run wiring in order to install cabinets and built-ins.
The deck surrounding this hot tub was completely rotted.
All redwood. Notice how the supports interlock each other.
The completed deck.
This side was equally bad.
All the supports were covered to prevent rot.
The finished deck, cut around the tub.
The wall was very rotted. The studs had to be replaced or sistered.
Notice the accurate cutouts for the water spigot and the vents.
The corner post had to be replaced. A major job.