1809.7 Prescriptive footings for light-frame construction.

Where a specific design is not provided, concrete or masonry-

unit footings supporting walls of light-frame construction shall be permitted to be designed in accordance with Table 1809.7. Prescriptive footings in Table 1809.7 shall not exceed one story above grade plane for structures assigned to Seismic Design Category D, E or F.

TABLE 1809.7 PRESCRIPTIVE FOOTINGS SUPPORTING WALLS OF LIGHT-FRAME CONSTRUCTION a,b,c,d,e

NUMBER OF FLOORS WIDTH OF FOOTING THICKNESS OF SUPPORTED BY (inches) FOOTING (inches) FOOTING f

1 12 6

2 15 6

3 18 8

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm

a Depth of footings shall be in accordance with Section 1809.4.

b The ground under the floor shall be permitted to be excavated to the elevation of the top of the footing.

c Interior stud bearing walls shall be permitted to be supported by isolated footings. The footing width and length shall be twice the width shown in this table, and footings shall be spaced not more than 6 feet on center.

d See Section 1908 for additional requirements for concrete footings of structures assigned to Seismic Design Category C, D, E or F.

e For thickness of foundation walls, see Section 1807.1.6.

f Footings shall be permitted to support a roof addition to the stipulated number of floors. Footings supporting roof only shall be as required for supporting one floor.

(Ord. No. 3143, § 4, 12-13-22)