What Is the Clearance From a Stove Pipe to the Ceiling?

Importance of Stovepipe Clearance

• Wood-burning stoves with stovepipes are categorized as vented stoves. The stovepipe connects to the chimney to vent smoke outdoors instead of into the home. A stovepipe becomes very hot when a wood stove is fired up and requires safe clearance from the ceiling, walls and combustible surfaces. The stovepipe must never pass through or connect to a chimney through a ceiling, only through walls. If you do not follow NFPA guidelines, you will be in violation of local safety and building code regulations and put yourself, your family and your home at risk for a fire. You must also adhere to local ordinances that may supersede NFPA guidelines.

Unprotected Ceilings

• Ceilings made of combustible materials are classified as “unprotected.” This includes ceilings made of wood, drywall and gypsum board on wood studs, and plaster on any type of wood backing. The NFPA recommends an 18-inch clearance space from the top of the stovepipe to the ceiling for both radiant and circulating wood stoves. Radiant stoves emit heat from the exterior surfaces and from the interior firebox. Circulating stoves have fans or blowers that distribute warm air into rooms and are typically newer wood-burning stoves.

Asbestos Millboard Ceiling Protection

• One-quarter-inch asbestos millboard is commonly used for ceilings above wood stoves and ceiling areas above stoves. If you use this material and nail it directly to the ceiling, the NFPA-required clearance is 18 inches, which is the same for an unprotected ceiling. However, if you space the millboard 1 inch away from the existing ceiling, the required clearance is reduced to 12 inches for radiant and circulating stoves.

Sheet Metal and Millboard

• Some homeowners attach a layer of 28-gauge sheet metal on top of 1/8-inch asbestos millboard. This creates a self-made heat shield for the ceiling area above the wood stove. If you use this technique and nail the sheet metal and millboard heat shield directly to the ceiling, the NFPA-required clearance is also 12 inches -- the same as for spacing millboard 1 inch away from the wall -- and applies to both radiant and circulating stoves.

Spaced Sheet Metal and Millboard

• If you leave a 1-inch space between a piece of 28-gauge sheet metal or millboard topped with a layer of 28-gauge sheet metal and the ceiling, you only need to allow a 9-inch clearance. You can bypass the millboard if you like, or you can add the millboard and drop down to a 1/8-inch thickness. A 9-inch clearance is the minimum NFPA ceiling clearance recommendation for the safe installation of stovepipes.