The construction of a DIY outside metal chimney, or prefabricated metal chimney, follows the same basic procedures as for an interior installation, except most of the installation is routed along an exterior wall. A metal chimney serves the same purpose as a masonry chimney: create a draft to draw the oxygen required for the appliance combustion process and exhaust smoke, fumes, embers and gases through the chimney.
Like all chimneys, an outside metal chimney must be well-constructed. It must be assembled in a manner that meets the specifications of the appliance and the local building codes. Plan the layout of the chimney as close to the appliance as possible. Usually, this is an adjacent wall.
The materials used for the construction of interior chimneys are the same as used for DIY outside metal chimney projects. Use double-wall (insulated) or triple-wall pipe. The formal Underwriters Laboratories (UL) label is UL-approved Stainless Steel Class A Insulated Chimney. The insulated chimney pipe is used the most. Insulated pipe is constructed of two layers of pipe, with 1 or more inches of a heat-resistant insulation sandwiched in between the stainless steel pipes.
Triple-wall chimney pipe consists of three pipes. It is constructed in a manner that allows air to circulate between the pipes, which gets rid of surplus heat. It doesn’t matter which pipe you select for your DIY outside metal chimney as long as the pipe is listed by Underwriters Laboratories.
Read the product owner manual and follow the local building codes for constructing the metal chimney. Chimney pipes come in a variety of diameters. The size of the chimney pipe you should use is usually based on the port size. The port is located on the appliance. Increasing or decreasing the pipe size recommended by the manufacturer can harm the appliance’s performance. It can also void the product’s warranty.
Generally, the DIY outside metal chimney exits through a wall adjacent to the appliance. Install a chimney pipe wall thimble in an opening between two studs. The wall thimble allows you to pass chimney piping through the combustible wall framing. The stainless-steel insulated pipe must be stacked vertically, and to a minimum height as specified in the manual and per building codes.
Most chimneys have the same height requirements: the chimney must extend a minimum of 3 feet above the chimney line and 2 feet higher than any object within a 10-foot radius. Attach a roof vent cap to keep birds and debris out of the system.
Although it may not be required in all locations, you may want to construct a chase to round off your DIY outside metal chimney. A chase is a wooden frame construction that encases the chimney. The enclosure can be finished with material to match the existing building finish.
- Photo Credit Hemera Technologies/AbleStock.com/Getty Images
How to Build an Enclosure for an Electric Fireplace
An electric fireplace can add a sense of warmth to your home and enhance the appearance of any room. Some electric fireplaces...
How to Install a Chimney For a Wood Stove on A Metal Roof
Completing the installation of a new wood-burning stove involves extending the chimney piping through the attic space and roof. For metal roofing,...
How to Clean Stainless Steel Chimney Liners
Chimneys with a stainless steel liner require cleaning as frequently as other types of lined, and unlined, chimneys. Each type requires a...
How to Install a Metalbestos Chimney Pipe
Many wooden stoves use metal chimneys to vent smoke out of a home. Metalbestos chimney pipe is filled with mineral wool insulation....
How to: Stucco on a Chimney
If you're looking to add a certain distinct touch the exterior of your home, a stucco finish may be just the thing...
Outdoor Chimney Ideas
A chimney design does not have to be an afterthought. Use creativity to design a chimney that stands out as much from...
Exterior Metal Chimney Pipe Installation
A metal chimney installation is the least expensive alternative for a traditional masonry chimney. Metal chimneys have the capacity to handle to...
Build Chimney DIY
Building a chimney is completely within the capabilities of a do-it-yourself homeowner with average skills. Unless you are an extremely competent bricklayer...