General. Footings shall be of adequate bearing area to safely distribute all live and dead loads to the supporting soil without exceeding the bearing capacity of the soil. Footings placed in unstable soils shall be formed.
Type and size. Concrete footings, unless designed by structural analysis, shall comply with the following requirements:
Continuous footings. The minimum width on each side of the foundation wall shall measure at least four inches wider than the wall and the minimum depth shall be eight inches.
Pier and column footings. The minimum horizontal dimensions of column or pier footings shall be two feet by two feet and shall be at least 12 inches in depth.
Where variations in the elevations of the bottom wall footings are necessary, it shall be spanned with an approved lintel.
Exception. A vertical connection between the footings at the step may be constructed of concrete, eight inches thick and of the same width as the footings, if there is less than two feet difference in elevation.
Chimney and fireplace footings. Footings for chimneys or fireplaces shall be at least four inches wider than the outside dimension of the chimney or fireplace foundation and at least 12 inches thick.
Trench footings. Footings poured integrally with the wall, at least eight inches wide, may be used for a one-story structure when soil conditions assure that trench walls will not collapse.
Frost protection. The bottom of all footings shall be a minimum of four feet below grade. Footings shall not be placed upon frozen material.
Curing. Concrete footings shall cure at least 24 hours before foundation wall or wall forms are begun to be constructed.
Drain tiles. All foundation walls of basements, cellars or other occupied spaces shall have drain tiles on each side of such walls. [See § 756-21B(3) for basementless spaces.] Bleeder tiles shall be placed in the foundation footing at not more than eight-foot centers. Drain tiles shall be connected to a sump pit, provided with a pump to discharge the water at grade or shall be connected to the storm sewer house drain. Drain tiles shall be covered with 12 inches of No. 2 washed stone or other approved porous material. Drain tile and stone shall be placed prior to starting the fourth foundation block course.
Foundation walls shall be of masonry and shall be continuous under all areas of the principal building including attached garage and shall be designed and constructed to support the loads placed thereon without exceeding the allowable stresses of the materials therein.
Exceptions. Overhanging bays and projecting floors are permitted, providing that such cantilevered floors do not exceed four feet. Cantilevered porches and balconies may project six feet, providing they do not support a roof. In each case, the joists must return twice the distance they project. Clear minimum space of eight inches shall be provided below the bottom of joists to grade.
Strength. Structural analysis shall be submitted to the Building Inspector when requested.
Decay and termite protection.
The top of foundation walls under all buildings or structures of wood frame construction shall be at least eight inches above lot grade at all exterior walls and no exterior wood siding or construction shall be less than six inches above grade.
Wood pressure treated with a preservative, or naturally durable decay-resistant species and grade of lumber or protected against decay and termites, may be used for:
Sills which rest on concrete or masonry walls and are less than eight inches from exposed earth.
Ends of wood girders entering masonry or concrete walls and having clearances of less than 1/2 inch on top, sides and ends.
Wood siding less than six inches from the earth.
Wood embedded in earth.
All pressure-treated wood shall be identified.
Foundation wall thickness.
Concrete foundation walls. Unless designed through structural analysis, the minimum thickness of concrete foundation walls shall be determined from Table 756-19A, but in no case shall the thickness be less than the thickness of the wall it supports.
Masonry foundation walls. Unless designed through structural analysis, the masonry foundation walls shall be constructed in accordance with the following requirements:
Unreinforced masonry walls; thickness. The minimum thickness of unreinforced masonry foundation walls shall be determined by Table 756-19B, but in no case shall the thickness be less than the thickness of the wall it supports.
Reinforced masonry walls; thickness. Reinforced masonry walls shall be reinforced in accordance with the requirements of Tables 756-19C and 756-19D. In partially reinforced masonry walls, vertical reinforcement shall be provided on each side of any opening, at each wall corner and at intervals indicated in the tables.
Pilasters. When a girder whose span exceeds 12 feet frames into a masonry wall, pilasters of a minimum size of four inches by 12 inches, built integrally with the wall, shall be provided.
Girder bearing. Four inches of end bearing shall be provided for girders framing into foundation wall, and when wood girders are used, an air space shall be provided between the foundation walls and the ends and sides of the girder.
Damp-proofing. Masonry foundation walls of basements and crawl spaces shall be made damp-proof by the application to the exterior surfaces thereof of a continuous coat of three-eighths-inch thick waterproof cement mortar or portland cement mortar plus a coat of bituminous damp-proofing material over the parging from top of stone to finish grade. One coat of bituminous damp-proofing material shall be applied to concrete foundation wall from the top of the stone to finish grade. When a minimum of one-eighth-inch thickness of an approved surface bonding cement is applied to exterior masonry foundation wall, it shall qualify as damp-proof.