(a) Scope. Wood burning appliances include factory-built fireplaces, fireplace stoves, room heaters, and fireplace inserts.
(b) Listing. Wood burning appliances shall be listed and accepted and shall be installed in accordance with the terms of their listing and acceptance.
(c) Location of appliances.
(1) Every appliance shall be located with respect to building construction and other equipment so as to permit access to the appliance. Sufficient clearance shall be maintained to permit cleaning of surfaces, the replacement of air filters, blowers, motors, controls and chimney connectors, and the lubrication and servicing of moving parts.
(2) Wood burning appliances shall not be installed in confined spaces or alcoves. The minimum size of the space or room in which the appliance is located shall be three hundred cubic feet. There shall be at least one openable window serving such space or room.
(3) Wood burning appliances shall not be installed in any location where gasoline or any other flammable liquids, vapors or gases are present or likely to be present.
(4) Wood burning appliances shall not be installed in any garage.
(d) Air for combustion and ventilation. Wood burning appliances shall be installed in a location in which the facilities for ventilation permit proper chimney draft and maintenance of safe temperature under conditions of use and provide sufficient air to prevent carbon monoxide from entering the dwelling space. Appliances shall be located so as not to interfere with proper circulation of air within the heated space. Where buildings are so tightly sealed that normal infiltration does not provide the necessary air, outside air shall be introduced.
(e) Mounting for residential type appliances.
(1) Residential type wood burning appliances that are tested and listed by an accepted national testing laboratory for installation on floors constructed of combustible materials shall be placed on such floors in accordance with the requirements of the listing and the conditions of acceptance. Such appliances which are not listed for installation on combustible floors by an accepted national testing laboratory shall be provided with floor protection in accordance with the provisions of subdivision (g) of this section. Residential type wood burning appliances are permitted to be placed without floor protection in any of the following manners:
a. on concrete bases adequately supported on compacted soil, crushed rock or gravel;
b. on concrete slabs or masonry arches that do not have combustible materials attached to the underside; or
c. on accepted assemblies constructed entirely on non-combustible materials, and having a fire resistance rating of not less than two hours, with floors constructed of noncombustible materials.
(2) Any floor assembly, slab or arch shall extend not less than eighteen inches beyond the appliance on all sides.
(3) In lieu of the requirements for floor protection specified herein, a floor protector listed by a recognized testing laboratory and installed in accordance with the installation instructions may be used.
(4) Appliances shall be supported by concrete bases, concrete slabs, masonry arches and floor ceiling assemblies and their supports which are designed and constructed to support the appliance.
(f) Mounting for fireplace stoves and room heaters.
(1) Fireplace stoves and room heaters which are set on legs or pedestals that provide not less than six inches of ventilated open space beneath the fire chamber or base of the appliance may be placed on floors of combustible construction, provided the floor under the appliance is protected with closely spaced solid masonry units not less than two inches in thickness. The top surface of the masonry shall be covered with sheet metal not less than 24 gauge (0.024 inches). The floor protection shall extend not less than eighteen inches beyond the appliance on all sides.
(2) Fireplace stoves and room heater which are set on legs or pedestals providing two to six inches of ventilated open space beneath the fire chamber or base of the appliance may be placed on floors of combustible construction, provided the floor under the appliance is protected with one course of hollow masonry units not less than four inches in thickness. The masonry units shall be laid with ends unsealed and joints matched in such a way as to provide a free circulation of air through the core spaces of the masonry. The top surface of the masonry shall be covered with sheet metal not less than 24 gauge (0.024 inches). The floor protection shall extend not less than eighteen inches beyond the appliance on all sides.
(3) Fireplace stoves and room heaters with legs or pedestals that provide less than two inches of ventilated open space beneath the fire chamber or base of the appliance shall not be placed on floors of combustible construction.
(g) Clearances. Woodburning appliances shall be installed with the following minimum clearances to combustible construction: Above the top of appliance – thirty-six inches; from front – thirty-six inches; from back – thirty-six inches; from sides – thirty-six inches. The minimum clearance to noncombustible construction shall be six inches when table 14-1 herein is used except that forty-eight inches shall be maintained where the fuel is inserted. Accepted stoves shall be exempt from the above-mentioned clearances and shall be installed in accordance with the appropriate reference standard and clearances determined therefrom through tests specified in the reference standard.
(h) Reduction of clearances from wood burning appliances.
(1) Clearances from listed and unlisted wood burning appliances to combustible material may be reduced if the combustible material is protected as described in table 14-1 herein and as shown in figures 14-6 to 14-10 herein.
(2) Clearances from wood burning appliances to combustible material may be reduced by the use of materials or products listed for the purpose of reducing such clearances. Materials and products listed for such purpose shall be installed in accordance with the conditions of the listing and the manufacturer's instructions.
(3) For clearance reduction systems using an air space between a combustible wall and wall protector, adequate air circulation shall be provided by one of the following methods as shown in figure 14-10 herein:
a. Adequate air circulation may be provided by leaving all edges of the wall open with an air gap of at least two inches.
b. If the wall protector is mounted on a single flat wall away from corners, adequate air circulation may be provided by leaving only the bottom and top edges or only the side and top edges open with an air gap of at least two inches.
c. Wall protectors that cover two walls in a corner shall be open at the bottom and top edges with an air gap of at least two inches.
(4) All clearances shall be measured from the outer surface of the combustible materials to the nearest point on the surface of the wood burning appliance, disregarding any intervening protection applied to the combustible materials.
(5) All clearances provided between wood burning appliances and combustible materials shall be large enough so as to maintain sufficient clearance between chimney connectors and combustible materials as required in subchapter fifteen of this chapter.
(i) Accessories. Factory-built accessories for wood burning appliances such as heat exchangers, stove mats, floor pads and protection shields shall be listed and accepted, and shall be installed in accordance with the terms of their listing and acceptance.
TABLE 14-1 REDUCTION OF APPLIANCE CLEARANCE WITH SPECIFIED FORMS OF PROTECTION 1,2,3,4,5,6,7,8,9,10
Clearance reduction system applied to and covering all combustible surfaces within the distance specified as required clearance with no protection | Maximum allowable reduction in clearance (percent) | When the required clearance with no protection is 36 in., the clearances below are the minimum allowable clearance. For other required clearances with no protection, calculate minimum allowable clearance from maximum allowable reduction. 9,10 | ||
As Wall Protector | As Ceiling Protector | As Wall Protector (in.) | As Ceiling Protector (in.) | |
(a) 3 1/2 in. thick masonry wall without ventilated air space. | 33% | – | 24 | – |
(b) 1/2 in. thick noncombustible insulation board over 1 in. glass fiber or mineral wool batts without ventilated air space. | 50% | 33% | 18 | 24 |
(c) 0.024 in. (24 gage) sheet metal over 1 in. glass fiber or mineral wool batts reinforced with wire, or equivalent, on rear face with ventilated air space. | 66% | 50% | 12 | 18 |
(d) 3 1/2 in. thick masonry wall with ventilated air space. | 66% | – | 12 | – |
(e) 0.024 in (24 gage) sheet metal with ventilated air space. | 66% | 50% | 12 | 18 |
(f) 1/2 in. noncombustible insulation board with ventilated air space. | 66% | 50% | 12 | 18 |
(g) 0.024 in (24 gage) sheet metal with ventilated air space over 0.024 in (24 gage) sheet metal with ventilated air space. | 66% | 50% | 12 | 18 |
(h) 1 in. glass fiber or mineral wool batts sandwiched between two sheets 0.024 in. (24 gage) sheet metal with ventilated air space. | 66% | 50% | 12 | 18 |
Notes for Table 14-1:
1 Spacers and ties shall be of noncombustible material. No spacers or ties shall be used directly behind appliance or conductor.
1 Spacers and ties shall be of noncombustible material. No spacers or ties shall be used directly behind appliance or conductor.
2 With all clearance reduction systems using a ventilated air space, adequate air circulation shall be provided. There shall be at least 2 in. between the clearance reduction system and combustible walls and ceilings for clearance reduction systems using a ventilated air space.
3 Mineral wool batts (blanket or board) shall have a minimum density of 8 lb. per ft
3
and have a minimum melting point of 1500°F.
4 Insulation material used as part of clearance reduction system shall have a thermal conductivity of 1.0(BTU-In.)/(Sq ft-Hr -°F) or less. Insulation board shall be formed of noncombustible material.
5 If a single wall connector passes through a masonry wall used as a wall shield, there shall be at least 1/2 in. of open, ventilated air space between the connector and the masonry.
6 There shall be at least 2 in. between the appliance and the protector. In no case shall the clearance between the appliance and the wall surface be reduced below that allowed in the table.
7 Clearances in front of the loading door and/or ash removal door of the appliance shall not be reduced from those in Section 8-6.
8 All clearances and thicknesses are minimums: larger clearances and thicknesses are acceptable. Clearances are not to be less than 12 in. from appliances.
9 To calculate the minimum allowable clearance, the following formula may be used: C
pr
= C
un
x (1-R/100). C
pr
is the minimum allowable clearance. C
un
is the required clearance with no protection, and R is the maximum allowable reduction in clearance.
10 Refer to Figures 14-11 and 14-12 for other reduced clearances using materials (a) through (h).
Figure 14-6
Figure 14-7
Figure 14-8
Figure 14-9
Figure 14-10
Figure 14-11
Figure 14-12