(1) All
roofs must be framed and tied into the framework and supporting walls to form
an integral part of the commercial coach.
(2) All trusses must be laterally
braced.
(3) All roof decks must be
designed and built with sufficient slope or camber to assure adequate drainage,
or must be designed to support maximum loads including possible ponding of
water due to deflection.
(4)
Cutting roof framework members for passage of electrical, plumbing, or
mechanical systems is prohibited except where substantiated by engineering
analysis.
(5) Electrical, plumbing,
or mechanical systems must not penetrate the roofing membrane unless the
penetration point is adequately sealed.
(6) Ventilation. Enclosed attics and enclosed
rafter spaces formed where ceilings are applied directly to the underside of
roof rafters shall have cross ventilation for each separate space by
ventilating openings protected against the entrance of rain and snow. Where
eave or cornice vents are installed, insulation shall not block the free flow
of air. A minimum of 1 inch of air space shall be provided between the
insulation and roof sheathing. The net free ventilating area shall not be less
than 1/150 of the space ventilated, except:
(a) The area may be 1/300, provided 50
percent of the required opening area is provided by ventilators located in the
upper portion of the space to be ventilated at least 3 feet above eave or
cornice vents; or
(b) A vapor
barrier not exceeding 1 perm is installed on the warm side of the attic
insulation.
