Quick question on flu pipe size, I have a brick chimney, and was wondering if the flu pipe was a common size. I want to start cleaning my own chimney, and need to know what size brush to get. I would rather only climb up once to clean it (not to measure flu pipe) and was hoping that brick chimneys all have the same size flu pipe and someone could tell me the size. If not I guess I will be taking a practice size real soon. Thanks