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<br />gradient, load intensity and erosion characteristics of slope
<br />material.
<br />
<br />1805,4 Footings. Footings shall be designed and constructed in
<br />accordance with Sections 1805.4.1 through 1805.4.6.
<br />
<br />1805.4.1 Design. Footings shall be so designed that the.
<br />allowable bearing capacity of the soil is not exceeded, and
<br />that differential settlement is minimized. The minimum
<br />width of footings shall be 12 inches (305 mm),
<br />
<br />Footings in areas with expansive soils shall be designed
<br />in accordance with the provisions of Section 1805.8.
<br />
<br />1805.4.1.1 Design loads. Footings shall be designed for
<br />the most unfavorable effects due to the combinations of
<br />loads specified in Section 1605.3. The dead load shall in-
<br />clude the weight of foundations, footings and overlying
<br />fill. Reduced live loads, as specified in Section 1607,9,
<br />are pennitted to be used in designing footings.
<br />
<br />1805.4.1.2 Vibratory loads. Where machinery opera-
<br />tions or other vibrations are transmitted through the
<br />foundation, consideration shall be given in the footing
<br />design to prevent detrimental disturbances of the soil.
<br />
<br />1805.4.2 Concrete footings. The design, materials and con-
<br />struction of concrete footings shall comply with Sections
<br />1805.4,2,1 through 1805.4.2.6 and the provisions of Chap-
<br />ter 19,
<br />
<br />Exception: Where a specific design is not provided, con-
<br />crete footings supporting walls of light-frame construc-
<br />tion are pennitted to be designed in accordance with
<br />Table 1805.4,2.
<br />
<br />1805.4.2.1 Concrete strength. Concrete in footings
<br />shall have a specified compressive strength if I,) of not
<br />less than 2,500 pounds per square inch (psi) (17237 kPa)
<br />at 28 days,
<br />
<br />1805.4.2.2 Reserved.
<br />
<br />SOILS AND FOUNDATIONS
<br />
<br />1805.4.2.3 Plain concrete footings. The edge thickness
<br />of plain concrete footings supporting walls of other than
<br />light-frame construction shall not be less than 8 inches
<br />(203 rom) where placed on soil.
<br />
<br />Exception: For plain concrete footings supporling
<br />Group R-3 occupancies, the edge thickness is permit-
<br />ted to be 6 inches (152 mm), provided that the footing
<br />does not extend beyond a distance greater than the
<br />thickness of the footing on either side of the supported
<br />wall.
<br />
<br />1805.4.2.4 Placement of concrete. Concrete footings
<br />shall n<?,t be placed through water unless a tremie or otber
<br />method approved by the building official is used. Where
<br />placed under or in the presence of water, the concrete
<br />shall be deposited by approved means to ensure mini-
<br />mum segregation of the mix and negligible turbulence 01
<br />the water.
<br />
<br />1805.4.2.5 Protection of concrete. Concr~te footings
<br />shall be protected from freezing during depositing and for
<br />a period of not less than five days thereafter, Water shall
<br />not be allowed to flow through the deposited concrete,
<br />
<br />1805.4.2.6 Forming of concrete. Concrete footings are
<br />pe~tted to be cast against the earth where, in the opin-
<br />ion of the building official, soil conditions do nOl require
<br />fonning. Where fonning is required, it shall be in accor-
<br />dance with Chapter 6 ofACI 318.
<br />
<br />1805.4.3 Masonry-unit footings. The design. materials
<br />and construction of masonry-unit footings shall campi)
<br />with Sections 1805.4,3,1 and 1805.4,3,2, and the prOVisions
<br />of Chapter 21,
<br />
<br />Exception: Where a specific design is not provided, ma-
<br />sonry-unit footings supporting walls of light-frame con-
<br />struction are pennitted to be designed in accordance wi rh
<br />Table 1805.4.2,
<br />
<br />1805.4.3.1 Dimensions. Masonry-unit footings shall be
<br />,laid in Type M or S mortar complying with Section
<br />
<br />II
<br />
<br />TABLE 1805.4.2
<br />FOOTINGS SUPPORTING WALLS OF LIGHT.FRAME CONSTRUCTIONa, b, c, d
<br />
<br />" WIDTH 01"
<br /> " THICKNESS OF
<br />NUMBER OF FLOORS FOOTING FOOTING
<br />SUPPORTED BY THE FOOTING' (Inoh..) (Inch.a)
<br />I 12 6 I
<br />2 15 6 !
<br />3 18 Sf
<br />
<br />II
<br />
<br />For SI: I inch = 25.4 mm, I foot = 304,8 mm"
<br />" Depth of footings shall be in accordance with Section 1805,2,
<br />b The ground under the floor is permilled to be excavated to the elevation of the top of the footing,
<br />c Interior-stud-bearing walls are permilted to be supported by isolated footings, The footing width and length shall be twice the width shown in this table, and foot,
<br />ings shall be spaced not more than 6 feel on center.
<br />II d, For thickness of foundation walls, see Section 1805,S,
<br />e Footings are permilted to support a roofin addition to the stipulated number of floors, Footings supporting roof only shall be as required for supponing one !loor
<br />f. Plain concrete footings for Group R-3 occupancies are permitted to be 6 incites thiclc
<br />
<br />FLORIDA BUILDING CODE - BUILDING
<br />
<br />18,5
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