Chimney Installation Regulations

Significance

• Chimneys serve appliances and fireplaces. Builders use similar materials for both and follow the same building codes to construct them so that byproducts are expelled at a rate and volume for effective combustion. A chimney's design, material and quality of construction all play significant roles in its function. A builder also must know and apply local building codes whether building a traditional masonry chimney or a modern pre-fabricated metal chimney.

General Requirements

• Regardless of the chimney, successful installation depends on factors such as sizing and insulation. In addition, chimneys also need proper clearance from combustible materials such as siding or wooden framing. Most local building codes will require that the height of a chimney must end 3 feet above its base. It also should extend at least 2 feet above any building component within 10 feet of the chimney.

Masonry Chimneys

• Bricks used for constructing the chimney must conform to American Society for Testing and Materials (ASTM) standards. Any other choice of masonry also must meet the rules for durability and heat resistance. Builders must mix mortar to comply with industry and building code standards, taking into consideration factors such as weather, insulation, wind resistance and temperatures. Municipal codes typically outline minimum wall thickness and flue requirements.

Flue Liners

• Masonry chimneys have one or more flue liners. The liners must conform to the ASTM C 315 standard. These liners are clay tile tubes mortared into the chimney's interior. Each flue handles the emission and draw requirements for one appliance or fireplace. Follow the appliance manufacturer's recommendations for proper flue size to ensure efficiency. Sometimes, a builder may join multiple flues to a primary discharge flue. The main flue must have the proper size for handling the combined flow emitting from smaller flues. The chimney also requires metal flashing and a cap to make the structure seal off water.

Pre-Fabricated Chimneys

• Renovation projects might call for the installation of factory-built metal chimneys. Metal chimneys, also known as Type A Stainless Steel, must meet ASTM and National Fire Protection Association requirements. Metal chimney pipes come in various diameters and lengths. Installers also can add elbows, caps or other supporting items for installation.