Community Development Department

Building Division www.cityofwestsacramento.org 1110 West Capitol Avenue West Sacramento, CA 95691 Ph: (916) 617-4645

Conventional Light-Frame Bracing (Seismic Design Category D) Design Provisions What is Light Wood-Frame Construction? The intention of a conventional light-frame construction method is to allow “repetitive” members in the designs of floors, walls, and ceiling – these shall be prescriptive and do not ordinarily require a structural design to comply with the code.

Who Can Design the Plans? Plans for single family dwellings of light wood-frame construction as defined by the 2013 CBC, Section 2308, may be prepared by any person, if the structure consists of not more than two (2) stories and basement in height. However, if the structure has unusual design features – if the design involves split levels, has framing irregularities, or has an unusual shape, size or weight – and deviates from conventional light-frame parameters, it shall be designed based on an engineered system. These plans shall be prepared by a professional architect or registered engineer, licensed in the State of California.

What types of buildings may use Light Wood-Frame Construction? The following are examples of the types of building where conventional light-frame construction may apply: • One, two or three-story buildings housing Group R Occupancies (residential). • Group U Occupancies (detached/attached private garages, sheds, and agricultural buildings). • Interior nonload-bearing partitions, ceilings and curtain walls in all other occupancies.

Wall Bracing Design Provisions (2013 CBC, Section 2308.3) • Braced wall lines are basic elements of conventional light-frame construction - exterior walls and main cross partitions are required to be braced to resist wind and seismic forces. • Braced wall lines shall consist of braced wall panels which meet the requirements for location, type and amount of bracing. Reference table in this handout and are in line or offset from each other by not more than 4-ft. • Braced wall panels shall start at not more than 8 feet from each end of a braced wall line. • All braced wall panels (i.e., type and length) shall be clearly indicated on the plans. Construction of braced wall panels shall be by one of the methods found under “Permitted Types of Braced Wall Panels”, page 3. • Braced wall panel sole plates shall be nailed to the floor framing with 3-16d nails per 16” on center. Blocking between joists or rafters shall be connected to the top plates with 3-8d toenails. Where joists are perpendicular to braced wall panels above, blocking shall be provided over and in line with the braced wall panels. • Spacing between braced wall lines shall not exceed 25-ft in both the transverse and longitudinal directions in each story. • Spacing of braced wall panels shall not exceed 25-ft on center. Refer to the diagram below. • Braced wall panels may be replaced by alternate braced wall panels which consist of not less than 2-ft 8-in and a height of not more than 10-ft. Refer to page four for sample details.

F:\CD Building\FORMS AND HANDOUTS 2014\Conventional Bracing (Jan 2014).docx

Page 1 of 5

BWL

Braced Wall Line

BWL L

25-ft max. spacing between Braced Wall Lines

BWL

Sample Floor Plan

BWL 6-ft max. overhang beyond Braced Wall Lines

8-ft max. from end of Braced Wall Line to beginning of Braced Wall Panel

MASTER BEDROOM

KITCHEN

BWL

CLOSET

BATH

25’ o.c., max. spacing between center of Braced Wall Panels

LIVING ROOM

BATH & CLOSET

BEDROOM ENTRY 85

BEDROOM BWL

4-ft max. offset in Braced Wall Line

25’ o.c., Max. Spacing Between Center of Braced Wall Panels

GARAGE

2’-8” min. wide Alternate Braced Wall Panels or Portal walls per 2308.9.3.2 (per figure next page)

WALL LEGEND Braced Wall Line Braced Wall Panel BWL

Alternate Braced Wall Panel

LOCATIONS AND TYPES OF BRACED WALL PANELS SHALL BE CLEARLY INDICATED ON THE PLANS SUCH THAT COMPLIANCE WITH CBC 2308 IS SELF-EVIDENT

Table 2308.12.4 Minimum Length of Wall Bracing per each 25 Linear Feet of Braced Wall Line SHEATHING TYPE

REQUIRED LENGTH

(a)

One Story

st

1 Story of two stories (a) (b)

Gyp Board Lath and Plaster

14’ – 8”

Structural Sheathing

(b)

8’ – 0”

Structural Sheathing

(b)

13’ – 4”

Gyp Board – Wall requires Gyp Board on both sides or one side with lath and plaster on the other side. Structural Sheathing – Wood structural panels (i.e., structural plywood or oriented strand board - OSB).

25-ft max. spacing between Braced Wall Lines

FAMILY

BEDROOM

Braced Panel Schedules & Sample Details ‘H’ for Stucco Braced Wall Panel 96” Min.

25’-0” Max.

NOTES: ◦ Brace Walls shall not be offset more than 4’-0” from each other. ◦ Shear panel types shall not be combined in the same line of resistance.

‘H’/2 for Wood Braced Wall Panel 48” Min.

‘H’ (Height of Panel)

8’-0” Max. from End of Wall

No penetrations permitted in Braced Wall Panels

BRACED WALL OPTIONS: ◦3/8” Struct. I Ply w/ 8d @ 6”/12” o.c. or OSB (common nails). ◦ 7/8” Stucco o/ Woven Wire or Expanded Metal Lath w/ No. 11 GA. nails. ◦ 1-1/2” x 7/16” heads w/ ¼” furring; applies to nailing at all studs, top and bottom plates & blocking.

Wall Bracing: One-Story Building Not to Scale

Alternate Braced Wall Panel Adjacent to a Door or Window Opening

Page 3 of 5

Sample Details This sheet is for information only and is not a substitute for accurate drawings prepared for each proposed construction project.

½” CDX plywood sheathing w/ 8d @ 6”/12” o.c. (common nails)

E.N. 8d @ 6” o.c.

2’-8” minimum, typ.

2X roof rafters w/ R-38 batt insulation 3/8” thick minimum (one side) wood structural panel sheathing

2X ceiling joists 2X solid blocking w/ framing anchor each block

E.N. .

*Plywood edge nailed w/ 8d @ 6”/12” o.c. (common nails) All panel edges blocked

Double top plate 2X4 stud wall @ 16” o.c. (DF stud grade-minimum) R-13 batt wall insulation

Types of BWP’s: Select from Braced Panel Schedule (pg. 3, methods 2-8)

2X P.T. sill w/ 1/2”-X10” anchor bolts @ 6’ o.c., 3” x 3” x 1/4” plate washers

Holdown each end of panel (1800# min. capacity)

3-1/2” concrete slab, 6X6-10/10 WWM o/ 2” sand bed, 6 mil vapor barrier

At foundation plate line, 26 GA weep screed 4” above grade (2” above concrete or paving)

Two anchor bolts @ each panel quarter point

FOUNDATION DIMENSIONS SHOWN BASED ON NON-EXPANSIVE SOILS

E.N. 8” Natural Grade

Concrete slab

#3 dowels @ 24”o.c. extend 36” into slab (for two-pour)

12”

#4 bar top & bottom 3” clear

12”

“L”

Installed distance per approved listing “L”/4

Alternate Braced Wall Panel: Slab-On-Grade (One-Story Elevation)

Wall Section: Slab-on-Grade Construction

Solid sheathing at floor or solid or skip sheathing at roof

Floor joists or cathedral rafters perpendicular to Braced Wall Panel (BWP) Solid blocking - nail each block per Nailing Schedule Braced Wall Panel (BWP) Top of Braced Wall Panels under roof, ceiling or floor framing

Joists/Rafter Perpendicular to Wall

Page 4 of 5

Nailing Schedule Table 2304.9.1 CONNECTION Joist to sill or girder Bridging to joist Sole plate to joist or blocking Sole plate to joist or blocking at braced wall panel Top plate to stud Stud to sole plate Double studs Double top plates Double top plates Blocking between joists or rafters to top plate Rim joist to top plate Top plates, laps and intersections Ceiling joists to plate Continuous header, two pieces Ceiling joists to plate Continuous header to stud Ceiling joists, laps over partitions (see Section 2308.10.4.1, Table 2308.10.4.1) Ceiling joists to parallel rafters (see Section 2308.10.4.1, Table 2308.10.4.1) Rafter to plate (see Sect. 2308.10.1, Table 2308.10.1) 1” diagonal brace to each stud and plate 1” x 8” sheathing to each bearing Wider than 1” x 8” sheathing to each bearing Built-up corner studs Built-up girder and beams 2” planks Collar tie to rafter Jack rafter to hip Roof rafter to 2-by ridge beam Joist to band joist Ledger strip Wood structural panels and particleboard Subfloor, roof and wall sheathing (to framing) Single Floor (combination subfloor-underlayment to framing)

Panel siding (to framing) Fiberboard sheathing

Interior paneling

FASTENING 3 - 8d common (2½” x 0.131”) 2 – 8d common (2½” x 0.131”) 16d (3½” x 0.135”) @ 16” o.c. 3 - 16d (3½” x 0.135”) per 16” 2 - 16d common (3½” x 0.162”) 4 - 8d common (2½” x 0.131”) 2 – 16d common (3½” x 0.162”) 16d (3½” x 0.135”) @ 24” o.c. 16d (3½” x 0.135”) @ 16” o.c. 8 - 16d common (3½” x 0.162”) 3 - 8d common (2½” x 0.131”) 8d (2½” x 0.131”) @ 6” o.c. 2 - 16d common (3½” x 0.162”) 3 - 8d common (2½” x 0.131”) 16d common (3½” x 0.162”) 3 – 8d common (2½” x 0.131”) 4 – 8d common (2½” x 0.131”) 3 - 16d common (3½” x 0.162”) min., Table 2308.10.4.1 3 - 16d common (3½” x 0.162”) min., Table 2308.10.4.1 3 - 8d common (2½” x 0.131”)

LOCATION toenail toenail each end typical face nail braced wall panels end nail toenail end nail face nail typical face nail lap splice toenail toenail face nail toenail 16” o.c. along edge toenail toenail face nail

2 – 8d common (2½” x 0.131”) 3 – 8d common (2½” x 0.131”) 3 – 8d common (2½” x 0.131”) 16d common (3½” x 0.162”) 20d common (4” x 0.192”) 32” o.c.

face nail face nail face nail 24” o.c. face nail at top and bottom staggered on opposite sides at each bearing face nail toenail toenail face nail face nail

16d common (3½” x 0.162”) 3 – 10d common (3” x 0.148”) 3 – 10d common (3” x 0.148”) 2 – 16d common (3½” x 0.162”) 3 – 16d common (3½” x 0.162”) 3 – 16d common (3½” x 0.162”) ½” and less 6d 19/32” to ¾” 8d or 6d 7/8” to 1” 8d 1 1/8”to 1 ¼” 10d or 8d ¾” and less 6d 7/8” to 1” 8d 1 1/8” to 1 ¼” 10d or 8d ½” or less 6d ½” No.11 gage roofing nail 6d common nail 25/32” No.11 gage roofing nail 8d common nail ¼” 4d 3/8” 6d

face nail toenail

Page 5 of 5