I did a chimney throat inspection last week. This Mason dissed about every other mason in the area, and how much better he was. I listened to the line but the throat area was ok. He had started the Wyth ( partition) that code requires to separate flue lines. Code and theory one flue to one chase separated by 4" soild block or masonry to any additional flues. This code was adopted in 1998, so it been on the books for 8 years. I drive by tonight delivering a cabinet I retrofitted and repaired. Guess what the flues are touching each other. I climb the pipe staging to confirm it. No partition wyth. This guy never figured I would be back before he finished. The calls will come into the office tomorrow and the crying starts. We had the discussion of it being code during the throat inspection. This chimney is comming down. He gets to practice doing it again. No wonder he is so good he gets to do things twice Code cut and paste 3610.2.9 Multiple flues: When two or more flues are located in the same chimney, masonry wythes shall be built between adjacent flue linings. The masonry wythes shall be at least four inches (102 mm) thick and bonded into the walls of the chimney.