(a) Joints in Type B and C vent piping shall be made gas tight.
(b) Type B vent piping shall be installed with a clearance to combustible material or construction, whether plastered or unplastered, of not less than one inch, provided that for vents of floor furnaces, water heaters and space heaters such clearance shall be not less than three inches for a distance of not less than three feet measured along the centerline of the vent piping, from the outlet of the draft hood.
(c) Suitable provision shall be made to prevent mechanical injury to Type B vent piping where it extends through walls, floors or roofs.
(d) Type C gas appliances vent piping shall not pass through any floor, attic or concealed space. When such vent piping passes through any combustible partition or combustible roof, the piping shall be guarded at the place of passage by double metal ventilated thimbles not less than six inches larger in diameter than the piping, or by double metal thimbles not less than four inches larger in diameter than the piping with the annular space filled with mineral wool or other approved noncombustible insulating material, or, in lieu of such protection, all combustible material in the partition or roof shall be cut away nine inches from the piping. Any material used to close up such opening shall be noncombustible.
(e) Type B or C vent piping shall not be used for solid or liquid fuel-burning appliances.
(Ord. 42-1981. Passed 2-23-81.)