#CHIMNEY MASONRY STACK HOW TO#
#CHIMNEY MASONRY STACK PROFESSIONAL#

Make sure you are building the chimney on a reinforced concrete pad. When building the chimney you should always work from the ground upward, which usually means you will start the project on top of the fireplace, if the chimney’s purpose is venting a fireplace. Tip: If you are building the chimney to vent a fireplace, use the same or similar type of brick that matches the fireplace’s hearth.

Bricks, concrete blocks or stone for the structure, cement mortar (a mix of one-part Portland cement, one-part hydrated lime and six parts builder’s sand is recommended), flashing, precast chimney cap made of concrete or stone, sheet metal and masonry tools such as a masonry trowel and level.

Wall thickness in residential homes for masonry chimneys needs to be a minimum of 4-inches thick.īefore you jump up and start building the chimney, make sure you have all your basic supplies on hand so you don’t have to stop in the middle of the project and run to the store.

Fill the space with a noncombustible material such as sheet metal.

It’s imperative that the masonry chimney has at least a 2-inch space on all four sides between it and any combustible materials, which includes wood framing, ceilings and the floor.

A gap of 1-inch is required between the outside of the tiled flue and brick surrounding it to reduce any chimney heat loss, which in turn improves draft.

Use a flue tile that is a minimum of 5/8-inches thick.

Line masonry chimneys with flue tile, which withstands rapid changes in temperatures and doesn’t crack, but has a smooth side to make cleaning the chimney easier.

For two-story homes, the footing needs to be 12-inches thick.

For single-story homes, the footings need to be 8-inches thick.

Footings need to extend no less than 6-inches beyond all four edges of the chimney.

Therefore, footings require enough strength to hold the chimney’s weight without settling and they need to be placed on well-compacted soil. Metal chimneys need to be 6- to 7-inches in diameter for venting stoves and central heating systems, or 8-inches in diameter for venting central heating systems, fireplaces and stoves.Ĭhimneys made out of masonry are generally the heaviest part of the house and are made out of noncombustible materials such as brick, stones or concrete blocks. Whereas, a flue venting a stove and central heater should be 7.5 x 7.5-inches or 8.5 x 8.5-inches. For example, masonry flues venting only a fireplace should be 13 x 13-inches.

Combined flues should have the main discharge flue appropriately sized to achieve the maximum amount of flow from the connecting smaller ones.

The shape and size of flue cannot change within 6-inches of any points where the chimney is going to pass through floors, roofs or ceiling areas that are combustible.

The slope of the flue isn’t greater than 30-degrees off vertical.

For example, you can have multiple flues for gas-operated appliances, but you cannot have multiple flues if you are discharging burning wood from one and gas in another.

Connecting flues are only discharging similar byproducts.

Multiple flues can be used to discharge byproducts if meeting certain conditions: These obstructions cause the air to blow down the chimney instead of across its outlet. Outdoor air currents can sometimes affect draft if they have to blow around obstructions such as areas of the roof or nearby trees. Generally speaking taller chimneys create more draft than shorter ones. The draft is created when warm air (or smoke) naturally rises up through the chimney. Second, they release the combustion products outside the home’s living area keeping the air inside your home clean and safe to breathe.

#CHIMNEY MASONRY STACK HOW TO#

Functions Of A Chimneyīefore you learn how to build a chimney, you should first understand how a chimney works.įirst, they create a draft which pulls in the required oxygen for creating combustion. However, if you have some masonry experience and you're confident with do-it-yourself type projects, building a chimney yourself is not only rewarding, it's a lot cheaper.įor starters, visit the National Fire Protection Association to view many local codes and regulations.

#CHIMNEY MASONRY STACK PROFESSIONAL#

If you don't feel comfortable with the project, sometimes it pays to just hire a professional who builds chimneys for a living.

Chimney masonry stack