Due to the many differences between fireplace brands and types, there is no set minimum distance that can be referenced across the board. Many direct vent appliances require a minimum of 6 inches of horizontal vent or 2 to 3 feet of vertical vent. Wood burning fireplaces typically call for 15 feet of venting, which is measured from the base of the fireplace to the top of the chimney termination. There is also the 10/3/2 rule that pertains to wood burning fireplaces. The rule states that the chimney must extend 3 feet above the roof penetration on the upward side of the pipe, and the top of the chimney must be 2 feet higher than any portion of the building structure within 10 feet. Depending on your roof slope, this could make for as little as 3 feet of chimney above the roof or as much as 15 feet or more. When in doubt, we highly recommend contacting our NFI certified technicians to discuss your installation further. Another resource is our chimney pipe quote form. This form allows you to share all aspects of your installation, providing the details needed for our specialists to generate a thorough quote.