What is the minimum clearance around a chimney?

Author: Johann Jast  |  Last update: Sunday, March 23, 2025

Headers, beams, joists, and studs shall be at least two inches from the outside face of a chimney or from masonry enclosing a flue. Trimmers shall be not less than five inches from the inside face of the concrete or masonry chimney wall. Finished flooring shall have at least one-half inch clearance from chimney walls.

How much space do you need around a chimney?

For interior chimneys, a 2 inch minimum air space between the chimney and combustibles must be maintained. An interior chimney is defined as any chimney having 1 or more walls inside a structure. For exterior chimneys, a 1 inch minimum air space must be maintained between the chimney and combustibles.

How much to close off a chimney?

Properly closing up a chimney involves closing and sealing the damper, installing a chimney cap damper, and sealing the fireplace opening with a door or bricks. The cost to seal and cap a chimney is around $500 to $650—significantly less than the average chimney removal cost.

What is the code on framing around a chimney?

Combustible framing shall be not less than 2 inches (51 mm), but shall be not less than the distance specified in Sections 2111 and 2113 and the California Mechanical Code, from flues, chimneys and fireplaces, and 6 inches (152 mm) away from flue openings.

What is the rule for chimney clearance?

This rule means that your chimney's shortest side needs to be at least 3 feet above the roof penetration, and its top has to be 2 feet higher than any part of the building that's within 10 feet. There a number of reasons behind this rule.

How To Calculate Fireplace Chimney Height Above Roof - Building Code Tips

What is the minimum clearance for a chimney?

The minimum distance between the chimney connector and any combustible material or construction shall be: (1) eighteen inches for chimney connectors from low temperature equipment. (2) thirty-six inches for chimney connectors from medium temperature and high temperature equipment.

What is the 7 times rule for chimneys?

(c) An existing chimney may only be utilized with one or multiple gas appliances if the interior area of the chimney is no greater than seven times the area of the smallest flue to be connected to that chimney. burning appliances is used with an appliance using fuel gas, an accessible cleanout shall be provided.

How close can framing be to chimney?

(A) All wood floor and roof framing shall be kept at least 2 inches away from the chimney masonry, except when 8 inches of masonry is used outside the flue lining, in which case the framing may be built flush with the chimney masonry.

What is the code for surrounding a fireplace?

The National Fire Code dictates that any combustible material (e.g., wood mantel or similar trim) must be at least six inches from the firebox opening. An additional inch of clearance is needed for every 1/8 inch the combustible material or trim protrudes.

What is the minimum gap permitted around a flue or chimney?

Air gaps to non-combustibles above stoves? 10cm minimum. Strive for 20cm. You need 35cm minimum between top of stove and chimney closure plate if fitting two offset elbows or a pipe with a soot door (soot door only required if you cannot sweep through the stove for some strange reason).

How to close off a chimney permanently?

This can be done by installing a chimney cap or cowl at the top of the chimney. This method of blocking off a chimney is considered one of the most secure.

Does a chimney add value to a house?

Any kind of fireplace will appeal to homeowners, but some could be more valuable than others. This depends on its installation, where the chimney is, or if it is on a mantel on its own. While some may be more expensive than others, a fireplace will increase your home's value.

Do capped off chimneys need to be vented?

Does a Capped-Off Chimney Need to be Vented? The short answer is yes. Though capping your chimney will block some of the drafts, it won't stop all of them. That's why it's important to vent your capped chimney.

What is the 2 10 rule for chimneys?

This is a pretty basic rule for chimney construction. A chimney must project at least 3 feet above the roof on its shortest side and also be at least 2 feet above any roof structure that is within a 10 foot radius of the chimney. That's it.

What is the minimum space required for chimney?

The space between the stove and the chimney should be between 26 and 32 inches. When the gas stove is turned on without a utensil on the burner and the distance between the two spots is less than 26 inches, the oil in the collectors has the potential to ignite, resulting in an explosion in the chimney.

What is the minimum clearance for a fireplace?

All combustible mantels and similar trim shall be kept at least 6 inches from fireplace openings. Parts of the mantel assembly located along the sides of the fireplace opening, which project more than 1-1/2 inches from the face of the fireplace, shall have additional clearance equal to the projection.

What is the clearance for a fireplace side?

Fireplace Opening Clearance Requirements

The fireplace facing clearance requirements vary depending on how much it projects above the brick face. 6" is of clearance from combustibles is required on either side of the opening and above, but 12" is required above the opening if the the facing projects more than 1 1/2".

How much space do I need around a fireplace?

We recommend leaving at least 45cm between the top of your fire and electrical equipment, such as a TV. Practice the same caution for all flammable objects, with at least 60cm in all directions from your fireplace, especially if the flame is open, as with our wall-mounted Alden range.

Can you put drywall next to a fireplace?

While drywall is fire resistant and used in fire-rated wall and floor/ceiling assemblies, it is not rated for use in fireplace insert surrounds. Radiant heat from pellet or gas inserts dries the cover paper, which is combustible and can pose a fire hazard.

What is the code for framing around a chimney?

Combustible framing shall be not less than 2 inches (51 mm), but shall be not less than the distance specified in Sections 2111 and 2113 and the International Mechanical Code, from flues, chimneys and fireplaces, and 6 inches (152 mm) away from flue openings.

How much clearance do you need for a chimney?

Headers, beams, joists, and studs shall be at least two inches from the outside face of a chimney or from masonry enclosing a flue. Trimmers shall be not less than five inches from the inside face of the concrete or masonry chimney wall. Finished flooring shall have at least one-half inch clearance from chimney walls.

How close can wood be to a fireplace?

The wood framing must be held back at least 2 in. from the sides and front of the fireplace and 4 in.

What are the requirements for a chimney for a wood-burning fireplace?

A chimney must extend at least 3 feet above a flat roof and at least 2 feet above a roof ridge or any raised part of a roof within 10 feet. Sometimes getting enough vertical clearance to prevent eddy currents from affecting chimney draft is impossible. This may be because of unusual heights of nearby trees.

Why do old houses have two chimneys?

In older houses located in colder climates, it was fairly common to have one chimney with two or more separate flues. This would allow a homeowner to vent, say, an oil-burning appliance as well as one, two, or even three wood-burning stoves/fireplaces. “Older” is the keyword here: these houses were not airtight.

How do most chimney fires start?

"Flue fires are perennial". They happen every winter when creosote deposits on the smoke chamber and flue walls are set ablaze by high heat or by flames licking up the chimney. A chimney fire can be exciting and light up the night, but it is NEVER a laughing matter.

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