Mantel height isn’t a random decision; the [National Fire Protection Association](http://www.nfpa.org/codes-and-standards) — the NFPA — sets criteria regarding positioning of a mantel in relation to the fire box. Local building codes can also order considerations and criteria. In both scenarios, there are variations from fire kind — wood burning, gas insert, canister, electric — and also way of ventilation. **Before you set up** a fireplace, surround or mantel: * Check any local code or by-law restrictions. * Check the company’s manual, which should provide particulars regarding minimum clearance conditions.
Minimum Mantel Vertical Clearances
The NFPA says that mantel thickness is directly related to the required height clearance between the surface of the fire box and the base of the mantel. For combustibles, such as wood or particle board, encompassing a sloping fireplace: * A 2-inch thickness needs to have a minimum height clearance of 11 inches. * A 4-inch thickness needs to have a minimum height clearance of 13 inches. * A 6-inch thickness needs to have a minimum height clearance of 15 inches. * An 8-inch thickness needs to have a minimum height clearance of 17 inches. * A 10-inch thickness needs to have a minimum clearance of 19 inches. **Confirm manufacturer’s installation instructions** prior to finalizing a mantel style; some wood-burning fireplaces must have a minimum 12-inch clearance.
Minimum Mantel Horizontal Clearances
Mantel height is frequently the principal concern of homeowners, however, mantel width can also be important. In the case ofhorizontal clearances of woodwork or other combustible materials](http://www.fireplacesnow.com/mantel.asp), frequently as a trim thickness, the projection of the end material impacts the space required from the outside border of the fire box into the interior edge of this trim: * less than 1 1/2 inches thick requires a minimum 6-inch clearance. * Facing 1 1/2 inches or heavier requires a minimum 12-inch clearance.
Materials Matter
Mantel material selection is an important consideration, both with regard to what is seen and that which stays unseen, as non-combustibles like glass, concrete or natural stone might be installed at a lower height. The unseen elements are equally, if not more important, than the visible. Stone applied over wood studs and regular drywall is substandard. To match lower height criteria, start with metal studs covered with non-combustible board and also affirm clearances with the manufacturer. If painting or applying different finishes to wood trim, brick or even firescreens, first assess the suitability of this end for heat-resistance and flammability.
Scale and Proportion
In addition to the several regulations and recommended allowances, proportion and scale should affect your layout. Identical fireplaces in 2 separate homes, one having an 8-foot ceiling and the other using a 20-foot ceiling, demand distinct mantel treatments. At the taller space, the mantel would make a unified statement using a wider and possibly thicker mantel. The treatment should extend up the wall, not stop at the 8-foot mark to chop the space in half.