M-1101.1 Scope: This chapter shall govern the reduction in required clearances to combustible materials and combustible assemblies for chimneys, vents, kitchen exhaust equipment, mechanical appliances, and mechanical devices and equipment.

M-1101.2 Protective assembly construction and installation: Reduced clearance protective assemblies, including structural and support elements, shall be constructed of noncombustible materials. Spacers utilized to maintain an air space between the protective assembly and the protected material or assembly shall be noncombustible. Where a space between the protective assembly and protected combustible material or assembly is specified, the same space shall be provided around the edges of the protective assembly and the spacers shall be placed so as to allow air circulation by convection in such space. Protective assemblies shall not be placed less than 1 inch (25 mm) from the mechanical appliances, devices or equipment, regardless of the allowable reduced clearance.

M-1101.3 Appliances in confined spaces: The clearance reduction methods specified in Table M-1103.3 shall not be utilized to reduce the clearance required for appliances installed in confined spaces in accordance with Section M-405.4.1.