Can an Outdoor Fireplace Go Against the House?

Two Kinds of Outdoor Fireplace, Two Rulebooks

Which rules apply depends on what the fireplace is. A factory-built outdoor fireplace is a tested, listed appliance; one outdoor wood-burning model, for example, is listed to UL 127 and comes with a manual that sets every clearance, the chase, the chimney and the cap. A masonry fireplace built on site follows chapter 10 of the 2023 Florida Building Code, Residential.

One detail in that manual answers a common question: the unit has no flue damper, and for that reason it cannot be installed indoors. An outdoor fireplace pushed against the house is still an outdoor fireplace, and its design assumes open air around it.

Clearance to the Wall

Against a block wall with stucco, a masonry fireplace has little to worry about. Against framed walls, siding or trim, the code sets distances. Section R1001.11 keeps wood framing and other combustibles at least 2 inches from the front and sides of a masonry fireplace and 4 inches from its back, with the gap left open except for fireblocking. Where the fireplace is built into a masonry wall, combustibles stay at least 12 inches from the inside of the firebox lining.

Factory-built units follow their own numbers. The outdoor model's manual calls for at least 1/2 inch of air space between the fireplace and combustible materials, a chase built outside the house's weather envelope, and a flashing detail where the platform meets the wall like the one used for an attached deck.

Eaves, Soffits and the Roof Overhead

A chimney that runs up beside the house meets the eave. Section R1003.18 allows a masonry chimney located entirely outside the exterior walls, including one that passes through a soffit or cornice, a minimum 1 inch air space to combustibles, kept open.

Height is the rule that catches people out. Section R1003.9 wants a chimney at least 3 feet above the roof where it passes through and at least 2 feet higher than any part of a building within 10 feet. A short outdoor chimney tucked under a two-story wall breaks the second half of that rule, and the factory-built manual repeats it for its termination cap, adding that the cap should sit away from trees and other structures.

Smoke at Windows and Doors

We found no Florida code distance between a wood-burning outdoor fireplace and a window, so the chimney height rule does that job. A chimney that clears the roof within 10 feet carries smoke above the eaves; one that stops below the roofline lets it roll along the wall and in through the nearest window or sliding door.

Wind direction matters as much as height. EPA asks people burning outdoors to think about wind and neighbors, and the same applies to your own bedroom window. If you smell smoke inside the house while the fireplace burns, EPA's guidance is that something may be wrong.

Water Where the Fireplace Meets the House

A fireplace against the wall also makes a new place for rain to get in. The factory-built manual says its outdoor unit sheds moderate amounts of water but is not waterproof, slopes the platform and hearth away from the house at 1/8 to 1/4 inch per foot, and recommends a drainage pan with tubes or weep holes wherever water can collect.

• Flash the joint between the fireplace platform and the house wall.
• Slope the hearth and platform away from the house.
• Give the chase top a drip edge and a collar around the chimney pipe.
• Keep a listed cap on the chimney.

Planning It Against Your Wall

Placement against the house is decided before the footing is poured, and it is the core of our outdoor fireplace installation visit: the wall, the eave, the roof within 10 feet, the windows and the drainage. The visit is a free inspection with a written estimate, from a local family company and its experienced masons.

Proudly American, we build it so the smoke goes up, not in, and our Proudly American crew checks the roof height from the yard before anything else.