(a) Exterior stud walls and bearing partitions shall be designed to carry safely all loads including loads on exterior stud walls due to wind or other lateral forces.
(b) Stud framing shall be of studs not less than two (2) inches by four (4) inches, spaced not more than sixteen (16) inches on centers for two (2) story and two and one-half (2-1/2) story construction; for construction less than two (2) stories in height, properly braced and assembled so that the assembly provides adequate rigidity, spacing may be increased up to twenty-four (24) inches on centers when specifically approved by the Commissioner. Studs shall be set with the larger cross-sectional dimension at right angles to the wall or bearing partition unless designed as individual columns.
(c) Stud framing having an unsupported height of more than ten (10) feet shall have studs bridged or otherwise braced in an approved manner at intervals not exceeding eight (8) feet. For bridging required to secure required fire resistance ratings, consult list of approved fire resistance ratings issued by the Board of Building Standards and Building Appeals.
(d) The maximum unsupported height, without intermediate lateral bracing from floors or structural members, shall be fourteen (14) feet for four (4) inch studs, and twenty (20) feet for six (6) inch studs.
(e) Sills shall be anchored to foundations by bolts not less than one-half (1/2) inch in diameter embedded not less than fifteen (15) inches in masonry unit walls and piers and not less than six (6) inches in cast-in-place concrete, and spaced not more than eight (8) feet on centers. Not less than two (2) bolts shall be used for each sill member, and, in all cases, bolts shall be provided within twelve (12) inches from the ends of each sill member. Bolts shall be firmly anchored in the foundation masonry or concrete.
(f) Corner or diagonal braces shall be installed at all external corners of exterior stud framed walls and securely nailed to all members over which they are applied, except that corner braces may be omitted when:
(1) Wood sheathing boards are used and applied diagonally;
(2) Forty-eight (48) inch wide or wider plywood sheathing is used; or
(3) On one (1) story dwellings, and at the second story of two (2) story dwellings, sheathed with approved three-fourths (3/4) inch fiberboards, one-half (1/2) inch gypsum board, or five-sixteenths (5/16) inch plywood, or with other material providing equal or greater resistance to racking loads, when fifty percent (50%) or more of the wall surfaces are without openings.
(g) Corner braces shall be one (1) inch by four (4) inch boards, or approved equivalent, let into the outside faces of the studs and set at an angle of approximately forty-five (45) degrees. Corner braces shall be installed at or adjacent to the corners, and wherever possible, shall extend from bottom of sills to tops of plates.
(h) When exterior openings are located adjacent to the corner and one (1) piece corner braces from sill to plate cannot be installed, corner braces shall be provided which extend over at least three (3) stud spaces and connect the corner post to the sill and the corner post to the top plate.
(i) Sills and girders supported on top of foundation walls or piers shall be leveled and grouted with Portland cement mortar; wood shall not be used for permanent shims.
(j) Studs shall be doubled at the sides of openings in exterior stud walls and bearing partitions; the inner stud shall extend in one (1) piece from bearing to header and shall be nailed to the outer stud: except that in lieu of doubled studs equivalent solid members may be used, or, where allowable stresses in single studs are not exceeded and approved formed metal or other supports and fastenings are provided at lintels, openings may be framed with single studs.
(k) All lintels shall be designed to support the superimposed load and shall have bearing of at least one and one-half (1-1/2) inches.
(l) Plates of exterior stud walls and of stud bearing partitions shall be not less than two (2) two (2) inch members of the same width as the studs, lapped at corners and intersecting partitions; except that when joists or studs are placed directly above studs below, a single top plate may be used. When plates are out for piping or duct work, an approved tie shall be provided on each side of the plate.
(m) Sill members of bearing partitions shall be not less than two (2) inches in thickness. If properly fire-stopped, studs may run through floors and rest on girders or on partition plates.
(n) In frame construction of two (2) or two and one-half (2-1/2) stories, where the exterior studs are not continuous from sill to roof and diagonal sheathing is not provided, other sheathing or connections, so designed and arranged as to supply adequate structural continuity between the first and second stories, shall be provided.
(o) Stud bearing partitions shall not be used in cellars, crawl spaces or air spaces. Stud bearing walls or partitions shall not be used to support more than two (2) floors and a roof.
(p) When two (2) inch by four (4) inch stud bearing partitions extend through more than two (2) stories and attic, the studs of such bearing partitions in stories below the upper two (2) stories shall be spaced not more than twelve (12) inches on centers for two (2) inch by four (4) inch studs, or shall be three (3) inch by four (4) inch or two (2) inch by four (4) inch studs spaced sixteen (16) inches on centers; in all such cases the partitions shall be subjected to engineering analysis to verify adequacy under the imposed loads.
(q) Ribbon Boards. Ribbon boards used to support joists shall be not less than one (1) inch by four (4) inch, shall be cut into the studs, and securely nailed with not less than two (2) tenpenny nails to each stud. The ends of joists adjoining studs shall be securely spiked to the studs. Wood blocking shall be inserted at the ends of joists not adjoining studs.
(r) Notching of Studs. In bearing walls or partitions no stud shall be cut more than one-third (1/3) its depth to receive piping or duct work, or for other purposes, unless approved supplementary framing or supports are provided.