Section 27-510
§ 27-510 Location and height. Tents or air-supported structures may be
erected inside or outside of the fire districts provided they are not
more than one story high above the ground, or above a roof that meets
the requirements of subchapter five of this chapter for fire divisions.
Section 27-511
§ 27-511 Separation. No tent or air-supported structure shall be
erected closer than twenty feet to any interior lot line nor closer than
thirty feet in any direction to an unprotected opening, required
exterior stairway or corridor, or required exit door, on the same level
or above the level of the tent or air-supported structure. A tent or
air-supported structure may abut another building on the same lot if
there are no unprotected openings or exits above or within thirty feet
as above stipulated, if there is no door between them that is a required
exit, and if the exterior wall separating them meets the requirements of
subchapter five of this chapter for fire divisions.
Exceptions. Requirements for separation from other buildings on the
site shall be waived where a tent or air-supported structure is used for
on-site temporary shelter for construction work, or incidental
fabrication of construction elements to be used on the site of
construction.
Section 27-512
§ 27-512 Fire protection. The ground enclosed by a tent or
air-supported structure, and the ground for a distance of at least ten
feet. outside of same, shall be cleared and maintained clear of all
combustible material or vegetation. No open flame of any kind shall be
employed within the structure, or closer than twenty feet to any part of
the enclosure fabric. Fire extinguishing facilities shall be provided in
accordance with the requirements of chapter four of this title.
Section 27-513
§ 27-513 Exits. Notwithstanding any other requirements of subchapters
six and eight of this chapter, travel distance to an exit from any point
within a tent or air-supported structure shall not exceed seventy-five
feet. Exit doors in air-supported structures shall close automatically
against normal operational pressures. Opening force at the edge of such
doors shall not exceed fifteen pounds, with the structure at operational
pressure. Exit doors shall be located in frames so constructed that they
will remain operative and support the weight of the structure in a state
of total collapse.
Section 27-514
§ 27-514 Structural requirements. (a) Tents. Tents shall be guyed,
supported, and braced to withstand a wind pressure of ten pounds per
square foot of projected area of the tent. The poles and their
supporting guys, stays, stakes, fastenings, etc. shall be of sufficient
strength and attached so as to resist wind pressure of twenty psf of
projected area of the tent.
(b) Air-supported structures.
(1) Air-supported structures shall be anchored to the ground or
supporting structure by either ballast or positive anchorage,
sufficiently and evenly distributed, and adequate to resist the
inflation lift load, the aerodynamic lift load, and the drag (shear)
load due to wind impact. The latter factors shall be based on a wind
velocity of at least seventy miles per hour, and an estimated stagnation
of not less than 0.5q for structures on grade whose height is equal to,
or less than, the width of the structure. For greater heights, or for
elevated structures, increased anchorage shall be provided, justified by
analytical and/or experimental data.
(2) The skin of the structure shall be of such strength, and the
joints so constructed, as to provide a minimum dead load strip tensile
strength at seventy degrees F of four times the seventy mph design load
(inflation and aerodynamic loading). The joints shall provide a dead
load strip tensile strength of one hundred sixty degrees F of twice the
seventy mph design load (i.e., a factor of safety of four and two
respectively). In addition, the material shall provide a trapezoidal
tear strength of at least fifteen per cent of the maximum design tensile
load. Material and joint strengths shall be so certified by the
manufacturer, justified by analytical and/or experimental data.
Section 27-515
§ 27-515 Flame resistance. (a) Tents. All materials used for tents
shall be treated to be flameproofed and shall remain flameproofed in
accordance with chapter four of this title. (b) Air-supported
structures. All fabrics that have a base fabric weight of 6.4 oz. per
square yard or less or that are used to enclose spaces classified in
occupancy group C, E, F, G, H or J shall have an extinction time of not
more than two seconds when tested under the small scale test method of
reference standard RS 7-3. All other fabrics shall have a flame
extinction time of not over one minute and/or a flame spread of not over
one inch per minute when tested in accordance with the provisions of
reference standard RS 7-4.
Section 27-516
§ 27-516 Pressurization system. Air-supported structures shall be
inflated and shall remain inflated during all periods of occupancy to a
minimum differential pressure of 0.88 in. and a maximum differential
pressure of 1.50 in. of water. Ventilation flow per occupant, either
through vents or anticipated leakage, shall comply with the requirements
of subchapter twelve of this chapter.
Occupied spaces. Where the net floor area per occupant is one hundred
fifty square feet or less, the structure shall be provided with at least
two blowers, each of which shall have adequate capacity to maintain the
required inflation pressure. Also, an auxiliary engine-generator set
capable of powering one blower, or a supplementary blower powered by an
internal combustion engine, either of which shall have the capacity to
run continuously for four hours, shall be located outside the structure,
shall be weather protected, and shall be arranged to automatically
operate the blower within twenty seconds upon failure of the normal
source. Heat shall be provided from a source outside the structure so
arranged as to prevent the spread of fire to the structure. The
temperature within the air-supported structure shall be maintained at
the temperature required by subchapter twelve of this chapter, but not
less than fifty degrees Fahrenheit during periods of snowfall.
Section 27-517
§ 27-517 Certificate of occupancy. Certificates of occupancy for tents
or air-supported structures shall be issued for a period not exceeding
one year, and such certificates may be renewed for one year periods
thereafter if the tent or air-supported structure complies with all
laws, rules and regulations in effect at the time of request for
renewal.