I recently planted a new deed as my old one was in a less than ideal location. My new deed is a waterfront deed and has access to iron, copper and zinc, so it's perfect. There was a wooden building that still had four walls left nearby. I put it into my perimter to speed up decay. All four walls were at about 80 - 90% decay and had less than 10 quality. Three of the walls decayed within a day, the fourth wall has been at 89% decay for three days now. Is this normal? How long does it normally take for buildings within your perimeter to decay?