 Can you share the reasoning why? Is it a code thing, or more an issue of simplicity of maintenance and performance long term? It seems very common to go near horizontally through exterior walls and then vertically up the side of the house and I'm just curious what the difference is with a setup like I'm proposing. B bholler Chimney sweep Staff member Jan 00, 0000 00,000 central pa Jul 00, 0000 #0 chhamilton said: Can you share the reasoning why? Is it a code thing, or more an issue of simplicity of maintenance and performance long term? It seems very common to go near horizontally through exterior walls and then vertically up the side of the house and I'm just curious what the difference is with a setup like I'm proposing. 