The fireplace surround is the area around the fireplace that is directly on the top and sides around the firebox. Because of fire safety rules, the fireplace surround has to follow a few rules that dictate the size, material and installation requirements that comply with the International Residential Code for fireplace surround materials.
Clearance From Combustable Materials
The fireplace clearances from combustible materials will dictate the size and type of fireplace surround.
Full Masonry Constructed Fireplaces--These types of fireplaces are incorporated into an entire wall. These fireplaces need a minimum clearance of 12 inches from the sides and top from combustible materials to meet code requirements. These fireplaces are wood burning, custom-built fireplaces.
Prefabricated Fireplace Units--These units are constructed in the factory and are made of steel. These units can be wood burning, gas, or pellet burning. These fireplace units fall into the category of minimum clearance requirements, where air spaces on the sides and back can be as little as 1 inch. This allows air to circulate around the unit. Direct contact under UL127 is permitted with the metal trim on these units as long as the manufacturers installation instructions are followed exactly.
Decorative Masonry Fireplaces--Masonry fireplaces that have mantels that project, must extend no more than 1/8 inch for every inch of the distance to the mantel from the top of the firebox. This is also the distance the noncombustible surround must be on the top. For example, if the mantel sticks out 3 inches, the top of the surround should be 12 inches.
The surround must be made of noncombustible material around wood burning masonry fireplaces such as tile, concrete, stone, marble or granite. Prefabricated units must have a fireplace surround that complies with the manufacturer's recommendations and clearances. Some prefabricated units can have direct contact with combustible materials including wood. These units are usually wood burning units. Always follow the manufacturer's recommended clearances in the instruction manual.
The fireplace surround of noncombustible and combustible materials must be fastened with noncombustible products. For prefabricated units that allow combustible materials, nails or screws may be used to to secure the fireplace surround. For masonry fireplaces where a noncombustible surround is needed, a noncombustible adhesive is also needed. Mortar, thin set, or any concrete based adhesive used to attach the tile,stone, marble or granite surround is acceptable. Construction adhesives like PL400, liquid nails or any other glue product that can burn or melt, is not permitted.