Kikuchi & Associates The issue of most concern with wood cabinets in the exterior is moisture absorption. If the wood absorbs moisture, it will shrink and swell and eventually deteriorate and rot. So, a very high quality paint or clear coating (such as polyurethane) that is kept up is very important. And the fabrication of the door frame joinery is very important. In highly exposed areas to both rain and sun, we will use wood that is resistant to rotting (redwood or cedar) and apply them to a metal frame or door as a veneer only, so that the door will not sag over time.