building is occupied by, or open to, the public; and shall be so constructed and maintained that they may be easily opened from within. (b) Revolving doors shall not be considered as complying with this section unless the wings of such doors are so arranged that by the application of a force slightly more than is necessary to revolve said doors and which one person of ordinary strength is capable of exerting, all the wings of said doors fold flat on each other and in outward direction, or unless the wings of said doors are so arranged that they may be readily collapsed or removed by pressure or simple mechanical means, and leave a minimum width of not less than twenty-two inches on each side of said collapsed doors. All revolving doors shall be approved by the local or State Building Commissioner before being opened to the use of the public. (c) Exit doors from stair halls shall not be less than 90 per cent of the width of the stairway. If elevators open into a stair hall, such exit door shall be increased six inches in width for each elevator. 274. COURTS AND LIGHT SHAFTS.] Court or light shaft of building used wholly or in part for the purposes of Class VI shall be open and unobstructed from the bottom of such court to the sky, with the exception that fire escapes may be built therein. Such courts shall have walls constructed as required for exterior walls of such buildings. 275. EXIT SIGNS AND LIGHTS.] (a) All exits in buildings more than two stories in height used wholly or in part for the purposes of Class VI shall be clearly indicated by illuminated red signs with the word "EXIT" thereon in letters not less than six inches high. If the bottom of a stairway on the street level is more than 25 feet from an exit, there shall be a similar sign indicating the direction of the nearest exit. (b) Fire-escape doors and windows shall be indicated by illuminated red signs with the words "FIRE ESCAPE" thereon in letters not less than six inches high. 276. SPECIAL REQUIREMENTS NOT TO EXCLUDE GENERAL PROVISIONS.] The following special requirements shall not be construed as exclusive of the general provisions of this Act. SPECIAL REQUIREMENTS FOR CLASS VIb BUILDINGS-MERCANTILE ESTABLISH MENTS. 277. PLACARD INDICATING SAFE LIVE LOAD ON FLOOR.] (a) In each story of every building used for the purposes of Class VIb existing or new, the owner, agent, occupant in charge or possession, must display conspicuously a placard, stating the maximum safe live load per square foot of floor, or if the safe load be not uniform, for each particular portion of such floor. It shall be unlawful to load any floor or portion thereof in excess of this stated maximum safe live load. (b) These placards must be exhibited and continuously maintained during the entire period of the use of the building for this purpose. Before posting them, such placards shall be verified and approved by the local or State Building Commissioner. 278. BASEMENT AND CELLAR.] (a) Not more than one floor below the lowest street grade shall be used for the sale of merchandise. (b) Locker and dressing rooms may be placed in the cellar or subbasement, provided the space thus occupied be separated from the remainder of the cellar or sub-basement by incombustible partitions, and that there be at least two flights of stairs, placed as far apart as practicable and leading therefrom to the first story, inclosed in fireproof partitions. Such stairs from such locker or dressing rooms shall be in addition to other stairways required by this Act for such buildings; and at least one of such stairways shall open directly on a street, alley or court opening on a street or alley, or on a fireproof passage leading to such street, alley or court. Where more than five lockers are in one room, such lockers shall be of incombustible material. 279. GALLERIES.] (a) The area of any or all of the galleries, mezzanine or intermediate floors in any story of any building used wholly or in part for the purposes of Class VIb shall not exceed 10 per cent of the area of such story. Galleries, mezzanine or intermediate floors of a larger size than the above shall be considered as full stories. (b) Every gallery, mezzanine or intermediate floor shall have at least one stairway not less than three feet wide. (c) The height from the floor of any gallery, mezzanine or intermediate floor to the ceiling over same shall not be less than 7 feet, and there shall be not less than 7 feet of space between the bottom of such gallery, mezzanine or intermediate floor and the floor of the story in which such gallery, mezzanine or intermediate floor is placed. 280. SIGNS AND LIGHTS FOR STAIR HALLS.] (a) The stair halls and passageways to exits shall be as wide as the stair, but not less than 4 feet wide in the clear. (b) The stairways and stair halls of any building used wholly or in part for the purpose of Class VIb shall be illuminated by sun light or by gas or electric light; and the gas piping and the electric wiring therefor shall be accomplished by piping and circuits separated and distinct from the general illuminating piping and circuits of the premises. Each stair light shall have a red glass inclosure. 281. AISLES.] (a) In buildings used wholly or in part for the purposes of Class VIb there shall be aisles connecting the stairways and the elevators directly with the street or alley doors. Such aisles shall have a clear width equal to the width of the stairways connecting therewith; and for each elevator connecting with such an aisle there shall be an additional width of six inches. No such main aisle shall be less than five feet wide in the clear between the counters or between the fixed seats therein. One third the width of any basement stairway shall be added to the width of the aisle connecting with such stairway. (b) If there is a column, counter or other obstruction in any such aisle, then the width of the aisle shall be increased by the width of such obstruction. ARTICLE XI-REQUIREMENTS CONCERNING STRENGTH OF CONSTRUCTION. A. DEAD AND LIVE LOADS, AND WIND STRESSES. 284. DEAD AND LIVE LOADS.] (a) The "dead load" shall include all permanent portions of the building, also all partitions and permanent fixtures and mechanisms supported by the building. The "live load" shall include all temporary or movable loads due to people, furniture or merchandise. (b) Buildings shall be so designated as to safely support the dead load and the live load hereinafter specified. (c) The "live loads" per square foot of floor area, except as hereinafter provided, shall be taken as not less than the following: (d) In class rooms of Class II buildings the live loads for floors having fixed desks need not be taken in excess of 50 pounds per square foot. (e) In buildings of Class V the floors shall be constructed to support a greater live load than that stated above, if the uses of the building require it. (f) Stairways and landings shall be constructed to safely support not less than 100 pounds per square foot of treads and landings. (g) The roofs of all buildings shall be designed and constructed to safely bear a live load, in addition to the weight of their structure and covering, of at least 25 pounds for each square foot of horizontal surface. (h) Floors, joists and beams shall be designed for the full dead and live loads." Floor girders shall be designed for the full dead load and not less than 85 per cent of the live load. (i) Live loads on walls, piers and columns shall comply with section 304. 285. WIND STRESSES.] (a) All structures shall be designed to resist a horizontal wind pressure of 20 pounds for every square foot of surface exposed to the wind in any direction from the ground to the top of same, including roof. (b) In no case shall the overturning moment due to the wind pressure exceed 75 per cent of the moment of the weight of the structure. (c) If the resisting moments of the ordinary materials of construction, such as masonry, partitions, floors and connections, are not sufficient to resist the distortion due to wind in any direction on any part of the structure, additional bracing shall be introduced sufficient to make up the difference in the stress. (d) In calculations for wind bracing, the unit working stresses for live and dead loads set forth in this Act for the several materials may be increased by 50 per cent. (e) In buildings under 100 feet in height, the wind pressure may be disregarded provided the height does not exceed twice the average width of the base. B. FOUNDATIONS. 286. FOUNDATIONS, WHERE NOT PERMITTED, DEPTH, DRAINAGE.] (a) Foundations shall not be laid on filled or made ground; but must rest on hard, firm soil, free from admixture of organic matter. (b) Foundations shall, in all cases, extend at least 4 feet below the finished surface of the ground upon which they are built, unless footings rest on bed rock. (c) In all cases where foundations are built in wet soil, the trenches shall be kept free from water until the work is completed, the cement has properly set, and the trenches have been refilled. 287. PROTECTION OF EXCAVATIONS.] The person causing any excavation for a building to be made shall have the same properly guarded and protected. Wherever necessary he shall at his own expense properly sheet pile and erect masonry or steel construction or a sufficient retaining wall to permanently support the adjoining earth. Such retaining wall shall extend the depth of excavation to the level of the adjoining earth, and shall be properly coped. 288. EXCAVATIONS AFFECTING ADJOINING PROPERTY.] (a) Whenever an excavation for a building or other purposes is to be carried below the bottom of the foundations of an adjoining wall or structure, or below the surface of an adjoining yard or bank, the person causing such excavation to be made shall from the commencement until the completion thereof, if afforded the necessary license to enter upon the adjoining land, at his own expense preserve any adjoining wall, structure, yard or bank from injury, and support the same by proper foundation or retaining wall, so that the said wall, structure, yard or bank shall be and remain as safe as before such excavation was commenced. For this purpose such foundations or retaining walls may be built upon the property upon which the wall, structure, yard or bank is situated. (b) If the necessary license is not accorded to the person or persons making such excavation, then it shall be the duty of the owner refusing to grant such license, at his own expense to make the adjoining wall, structure, yard or bank safe, and support the same by proper foundation so that adjoining excavation may be made, and such owner shall when necessary be permitted to enter upon the premises where such excavation is being made, for that purpose. 289. FOUNDATIONS ADJOINING PARTY WALLS.] (a) In case a party wall is intended to be used by the person causing an excavation to be made, and the footings and foundations of such party wall are in good condition and sufficient for the uses of both the existing building and the new one, then the person causing the excavation to be made shall, at his own expense, preserve such party wall from injury and support the same by proper means, so that said party wall shall be and remain as safe as before the excavation was begun. (b) In case the footings and foundations of any said party wall are not in good condition, or not sufficient for the uses of both the existing building and the new one, it shall be the duty of the person causing such excavation to be made to extend such defective footing for foundation, or to replace same with a new footing or foundation. Such extended or new footing shall project on each side of the party line such a distance as to bring the center of the footing under the center of the wall, so that the total load upon the wall may be uniformly distributed over the area of footing. Any other method may be used which will adequately support the party wall in accordance with the requirements of this Act. In order that this may be done, the person causing the excavation to be made shall be allowed access to the adjoining premises, for that purpose. If the necessary license is not accorded to the person causing such excavation to be made, then it shall be the duty of the other party to the ownership of said wall to extend such defective footing on foundations or to replace the same with a new footing or foundation as above described. (c) In case any excavation, or the removal of any existing building, shows any adjoining wall or structure to be made at the time the excavation was begun, it shall be the duty of the person causing the excavation to be made or the building to be removed, to forthwith report the fact in writing to the local or State Building Commissioner, who shall upon the receipt of such notice forthwith cause an inspection of such adjoining premises to be made; and if such inspection shall prove the aforesaid wall or structure to be unsafe, it shall be the duty of the local or State Building Commissioner to declare such wall or structure to be unsafe and order the same to be made safe. (d) If the person whose duty it shall be to preserve or protect from injury any wall or structure, shall neglect or fail so to do within twenty-four hours after the receipt of a notice from the local or State Building Commissioner, then the local or State Building Commissioner may enter upon the premises and employ such labor, and furnish such materials and take such steps as, in his judgment, may be necessary to make the premises safe and secure, or to prevent the same from becoming unsafe or dangerous, at the cost and expense of the person whose duty it is to keep the same safe and secure. (e) The expense incurred for labor or materials by the local or State Building Commissioner in making safe or protecting any such wall or structure, shall give to said local or State Building Commissioner the right to a mechanics lien against the estate in fee, for life or for years, or any right of redemption or other interest which such owner may have in the lot or tract of land. Said lien shall be enforced in the name of the local or State Building Commissioner for the use of the municipality or State in accordance with an Act of the Legislature to revise the law in relation to mechanics lien, chapter 82, sections 15 to 54, inclusive. 290. MATERIALS FOR FOUNDATIONS.] Foundations shall be constructed of rubble or dimension stone, plain or reinforced concrete, sewer or paving brick, steel beams imbedded in concrete, piles capped with grillage or concrete, or any approved combination of these materials. 291. CROSS SECTION OF FOOTINGS.] Foundations of stone, brick or plain concrete shall not be built with a batter greater than six inches horizontal to one foot vertical; and if stepped out, no step shall be wider than half its depth. 292. ALLOWABLE PRESSURE OF SOIL.] (a) Where masonry foundations rest directly upon natural soil, the total pressure thereon shall not exceed the following limits: Soft clay or undisturbed loam-1 ton per square foot. Firm moist clay or layers of clay and sand-2 tons per square foot. Hard dry clay or compact sand-4 tons per square foot. Gravel or hard pan-8 tons per square foot. (b) Whenever a doubt arises as to the safe sustaining power of the soil upon which a foundation is proposed, the local or State Building Commissioner may order tests of the sustaining power of such soil to be made at the expense of the owner of the proposed building. Such tests shall be made in accordance with specifications to be prescribed by the local or State Building Commissioner. The total load placed on the soil thus tested shall not exceed the safe sustaining power indicated by such tests. 293. PILE FOUNDATIONS.] For pile foundations either wood or concrete piles may be used. The piles shall be so arranged in the foundation that they will be equally loaded. 294. WOOD PILES.] (a) Wood piles shall be of approved timber, sound and reasonably straight. They shall not be less than 5 inches in diameter at the small end, nor less than 10 inch at the butt. Piles over 25 feet long shall be at least 12 inches in diameter at the butt. (b) The distance between piles shall not be less than twice the mean diameter of the pile. They shall be driven to a solid bearing if practicable; but shall not be driven so hard as to impair their strength. If driven with a drop hammer, the safe sustaining power of a pile in tons shall not exceed twice the weight of the hammer in tons multiplied by the drop in feet, and divided by the penetration under the last blow in inches plus one. If a steam hammer is used, the safe sustaining power shall not exceed twice the weight of the hammer in tons multiplied by the drop in feet, and divided by the penetration under the last blow in inches plus one tenth. No wood pile shall be loaded with more than 30 tons. (c) The tops of all piles shall be cut off below the permanent water line, if in sand or gravel; but in damp, impervious clay they may be cut off above the permanent water line if thoroughly sealed from contact with the air. (d) The piles may be capped with concrete or grillage timber. If concrete is used it shall be deposited to a depth of not less than 12 inches over the top of the piles and shall fill all spaces between the piles to a depth of not less than 6 inches below the tops, and shall extend 1 foot outside of the piles. If timber grillage is used, it shall consist of at least two courses of timber, not less than 6 inches thick, firmly bolted together, the upper course forming a solid floor and being laid in opposite direction to the lower course. Said grillage timber shall not be used unless it will be completely and permanently immersed in water. (e) Wood piles may be sunk with a water jet, but they shall be struck a few final blows with a hammer, and their sustaining power shall be determined as provided for in this Act. 295. CONCRETE PILES.] (a) Plain or reinforced concrete may be used for supporting foundations. If plain concrete piles are used, they must be moulded in place by a method approved by the local or State Building Commissioner. Reinforced concrete piles, if properly designed to resist the shock of driving, and if driven with a cushion to lessen the shock, or if put down by a water jet, may be moulded, allowed to harden, and then driven or jetted into place. (b) The sustaining power of concrete piles shall be determined by putting down one or more test piles and loading them after the concrete is sufficiently hard. The safe sustaining power of such a pile shall not be assumed at more than one half the load under which the pile begins to settle. In no case shall the load on a concrete pile exceed 500 pounds per square inch of cross section of the head of the pile. 296. STEEL RAILS OR BEAMS IN FOUNDATIONS.] If steel rails or beams are used as parts of foundations, they shall be entirely bedded in concrete extending not less than 4 inches outside the metal. C. STONE AND BRICK MASONRY. 297. DEFINITIONS OF STONE MASONRY.] (a) Ordinary rubble shall be defined as masonry composed of unsquared stones laid without attempting any regularity of courses or bond. (b) Coursed rubble shall be defined as masonry having approximately level bed joints, stones roughly shaped so as to fit approximately, bed joints in wall or pier leveled off at least every 3 feet in height, and being well bonded. (c) First-class stone masonry shall be defined as masonry built of stones in regular courses, the bearing surfaces of which, as well as the ends, are roughly tooled off. Such masonry shall be laid with alternate headers and stretchers in such a manner as to secure perfect bond. |