7. FLOORS SHEATHING PERPENDICULAR 
TO JOISTS 
Floor diaphragms are significant structural FIELD NAIUNG EDGE OF SHEET PLYWOOD BOUNDARY OR EDGE OF 
TO EACH JOIST NAJUNG TYP. EA NAIUNG TO RM JOIST OR BLOCKING 
elements especially in two story construction ALAON 
or if a first floor is required to span STAGGER 
horizontally across a basement or over a SHE T 
crawl space. Ideally, the floor should be SHI 
regular in shape and all in the same plane 
without vertical offsets. A simple rectangular, 
symmetrical shape (box) is the best 
configuration. See Figure 45. Where possible 
the earthquake forces in the floor diaphragm NDI 
should be resisted by a symmetrical pattern DIH JOIST NAICHNG 
of shear walls supporting the boundary of the D |RA SOLID AS 
floor. 
JOISTS 
WALL TOP PLATES ACT AS 
CORNER DIAHRAGM CHORD 
TYPICAL DIAPHRAGM 
Figure 46 
KITCHEN/ BEDROOM 
BREAK WALL FLOOR 
GARAGE EDGE 
EDGE NAILED TO WALL TO 
TO PLATE 
BLOCKING TOP PLATES 
Figure 45 
WALL PERPENDICULAR TO JOISTS 
WALLSILL 
BEDROOM 
A diaphragm consists of joists, sheathing and Figure 47 
edge members called chords. See Figure 46. 
Sheathing on floors serves the dual purpose  
of supporting the load of furnishings and 
occupants and of transferring earthquake or 
wind loads to the shear walls. Commonly used 
sheathing materials, when adequately nailed, 
carry the vertical floor loads and resist the 
earthquake loads in the plane of the 
diaphragm. Nailing for diaphragm action is/ 
generally greater than the nailing required for 
gravity loads. 
Figure 45 
WALL PARALLEL TO JOISTS 
Figure 48 
PLATES 
RIM JOIST
Plywood or oriented strand board for subfloors 
may be used in any seismic risk area. Tongue 
and groove sheets should be oriented with the 
long edge perpendicular to the framing and 
need not be blocked. The short edge of 
abutting sheets must be edge nailed to the 
same framing member. To achieve a stiffer 
diaphragm in areas of high seismic risk, 
square edge sheets with the long edges of 
each sheet nailed to blocking and short edges 
nailed to a common framing member should 
be used. Straight sheathing without a Wood 
Structural Panel overlay should be avoided 
except in low seismic risk areas. 
For two story construction or floor framing 
supported on stud walls, top plates act as 
flanges or chords for floor diaphragms. They 
should not be interrupted by openings such 
as windows, ducts, piping or conduits, unless 
chord continuity can be satisfactorily restored 
with straps or ties. Top plates must be 
internailed and receive additional nailing at lap 
splices. See Figure 47, 48 and 49. Wall top 
plates must continue across the full width and 
length of the floor diaphragm from corner to 
corner without interruption. Diaphragm 
sheathing must be edge nailed to blocking or 
rim joists that are toe nailed to the top 
plates. 
To function properly diaphragms must conform 
to specific shape limitations that are 
controlled by the diaphragm span-to-width 
ratio discussed before. If the allowable ratios 
are exceeded it is necessary to provide 
additional shear walls to divide the diaphragm 
in sections so that the sections meet the 
prescribed span-width diaphragm limits. Shear 
walls (panels) in line at the edge of a 
diaphragm, but separated, can be tied 
together by the wall top plates acting as 
collectors or drag struts between the shear 
walls. The top plates must be spliced for 
continuity. See Figure 50. Shear walls not at 
the edge of a diaphragm or within the 
diaphragm borders can also be used by 
employing light gage strap ties nailed to the 
shear wall and extending into and nailed to 
the diaphragm framing. See Figure 51. 
OR BOUNDARY ANCHOR BOLTS SEE 
NAIL SPACING 
FIG. 39 
TOP & BOT. 
EXTERIOR 
BLOCKING TOE NAILED TO 
BLOCK FOUNDATION SILL PLATE 
EACH BLOCK 
ANCHOR BOLTS 
8" MIN. 
Figure 49 
DIAPHRAGM 
No. 2.INTERMEDIATE SHEAR WALL TO 
REDUCE DIAPHRAGM RATIO. 
EACH WITHIN 
DIAPHRAGM 
TIE DIAPHRAGMS SHEATHING AT EDGE OF 
WITH COLLECTORS DIAPHRAGM No. 3 AND 
TO SHEAR WALLS INTERIOR OF DIAPHRAGM No. 1 
IN EACH EDGE NAILED TO COLLECTORS 
DIRECTION TOP PLATES CONTINUOUS WITH LAP SPLICES 
AT CORNERS TO COLLECT AND TRANSFER SHEAR TO SHEAR 
WALLS. TYPICAL AROUND PERIMETER AND 
INTERMEDIATE SHEAR WALLS. 
PLAN 
Figure 50 
PLAN 
Figure 51 
As for building wings, collectors or ties can be 
used to transfer earthquake loads developed in 
areas of a floor not supported on walls such as 
at porch enclosures that are open underneath 
and supported on posts. Collectors must be 
nailed to floor framing within enclosures and 
extend into and be nailed to floor diaphragm 
framing as shown in Figure 51 and 54. 
Sill plates must be bolted to the top of the 
footing or stem wall. See Figures 49 and 53. In 
high seismic risk areas, chances of plate failure 
are reduced by using a larger number of anchor 
bolts over the width of the shear wall than may 
be prescribed by Code and by the use of plate 
washers. Hold-down anchor bolts, where needed, 
must be embedded in the footing as shown in 
manufacturers' catalogs. See Figures 31 and 55. 
Where collectors or drag struts continue across 
a break in diaphragm planes the collectors or 
struts must be anchored to the vertical framing 
to prevent uplift when they are loaded by 
earthquake forces. See Figure 52. 
STRAP TIE NAILED 
TO BLOCKING 
SAME AS 
DETAILS BELOW AT CONDITION WHERE NO BEARING WALL 
BELOW NAIL STRAP TIE TO UNDERSIDE 
OF BLOCKING FOR TWO JOIST SPACES 
DIAPHRAGM EDGE 
OR BOUNDARY 
NAIL SPACING 
OPTIONAL 
1-#4 MIN. CONTINUOUS 
TOP & BOTTOM 
ANCHOR BOLTS 
BLOCKING 
SHEAR WALL SECTION 
HORIZONTAL FRAMING PARALLEL TO WALL 
Figure 53 
Figure 54 
WALL SHEATHING TO 
BOUNDARY NAIL HAVE EDGE NAILING 
SHEATHING TO HOLD-DOWN STUDS 
BLOCKING 
FRAMING CUP EACH BLOCK 
FOR HIGH AND MODERATE 
SEISMIC RISK AREAS 
INTERNAIL STUDS / 
STUDS EACH 
SHEAR WALL 
HOLD-DOWN STRAP EACH 
END OF SHEAR WALL 
NAIL STRAP TO PREVENT UPLIFT 
TO END FACE OF STUD AND 
TOP OF JOIST ABOVE 
BEND STRAP AND 
EMBED IN FOOTING 
STRAP HOLD-DOWN 
Figure 55 
HORIZONTAL DIAPHRAM TIE 
Figure 52 
A floor diaphragm or any of its parts should, where 
possible, be in one horizontal plane between shear 
walls and not be broken by vertical offsets or ramps. 
Where a floor plane is interrupted, as in split level 
construction (see Figure 56), the floor will then be 
composed of more than one diaphragm. Each of these 
diaphragms must have a boundary shear wall along 
each edge. At the offset edge, each diaphragm may 
use the common shear wall to resist the earthquake 
forces in each diaphragm. See Figures 58 and 59 for 
split level floor framing details. 
Openings in floor diaphragms must be limited. 
Penetrations at corners should be avoided. Small 
openings for furnace ducts and registers, flue stacks 
and chimneys are permissible. See Figure 57. Large 
openings for stair wells must receive special framing 
and nailing of floor sheathing around the opening. 
Where any opening dimension reduces the effective 
length or width of a diaphragm by 50% or more, a 
shear wall should be placed parallel with the narrow 
edge of the diaphragm on each edge of, or in line 
with, the edge of the opening. 
Ideally, floor diaphragms should be fastened with screw 
shank nails with a diameter equivalent to common or 
box nails. If nails other than common wire nails, such 
as box, sinker or staples are used, the spacing should 
be reduced from those prescribed in codes for 
common nails. To prevent squeaking a bead of 
construction adhesive should be applied on the top 
edge of floor joists when laying the sheathing. The use 
of adhesive in this manner has been shown to 
increase stiffness and improve performance of floor 
diaphragms in earthquakes. 
In addition, nominal nailing (at 10" to 12" spacing) 
must be provided along framing members located 
between the edges of the sheets. This nominal field 
nailing secures the sheathing to the framing and 
prevents buckling of the sheets when the floor 
functions as a diaphragm during an earthquake. When 
using a nailing gun, care must be exercised to avoid 
overdriving the nails. The gun operator should also 
make sure that the nails penetrate the framing EIL 
members below. It is good practice to locate the OF 
members below by snapping a chalk line on the top BC 
face of the sheathing. A new nail should replace S- 
each nail not properly driven. 
Blocking or rim joists should be nailed to 
top plates with 4-l1d toe nails each 
block or 10d toe nails at 4" centers for 
rim joists. Light gage angle clips can be 
used in lieu of toe nailing. 
LOWER 
ROOF 
LOWER 
FLOOR 
Figure 56 
OPENING
OUNDARY OR 
FEATHING TO 
Figure 57
UPPER 
SHEET METAL 
FRAMING ANCHOR 
MID-LEVEL OR 
LOWEROOF 
2-2x4 
2x4 STUDS 
2x4 FLAT BLOCKING 
FULL LENGTH 
OF MID-LEVEL 
BLOCKING 
(SHORTS) 
HOOK STRAP & NAIL 
TO EDGE OF BLOCK 
4x4 BLOCKING WITH 
FRAMING ANCHORS 
EACH END 
SPLIT-LEVEL TIE 
FLOOR FRAMING PARALLEL TO WALL 
Figure 58 
SPLIT-LEVEL TIE 
FLOOR FRAMING PERPENDICULAR TO WALL 
Figure 59 
SPLIT-LEVEL TIE 
SLOPING ROOF FRAMING PARALLEL TO WALL 
Figure 60 
SPLIT-LEVEL TIE @ 32
SLOPING ROOF FRAMING PERPENDICULAR TO WALL 
Figure 61 
8. SHEAR WALLS 
Shear walls resist earthquake loads transmitted to them 
by floor and roof diaphragms. A shear wall is required 
along each side of the perimeter of the floor or roof 
(horizontal) diaphragm, usually in each exterior elevation. 
The most effective locations for the exterior shear walls 
are at the corners of the building where the walls are 
mutually perpendicular to each other and have a 
common point of intersection. See Figure 62. To 
maintain symmetry, the same length of wall should be 
provided at each of parallel exterior walls. In order to K, 
minimize torsiornal rotation which can increase earthquake l 
loading on shear walls, an unbalanced condition should .
be avoided. See Figure 63. Some codes limit the 
maximum distance between shear walls and specify the 
percentage of an exterior wall that must be sheathed. 
For long walls, this may require placing one or more 
shear panels between the corners. See Figure 64 below 
and Figure 67 on page 34. If shear walls can not be 
placed at the corners, they should be located as near 
to the corner as possible. 
Shear wall configurations should conform to ratios that Figure 62 
limit height to width. See Figure 29 on page 19 and 
Table 3 on page 39. With a ratio of 2:1 for height to 
width, and considering a usual story height of 8'-O", the 
minimum width of wall to be provided at each corner of 
each exterior wall should be 4'-O" for moderate and 
high seismic risk areas. This ratio limit is also 
recommended for low seismic risk areas. 
SHEAR WALL- SHEAR WALL 
2ND FLOOR 
EAR PANEL 
FLOORPLAN 
UNBALANCED SHEAR WALL CONDITION 
Figure 63 
Figure 64 
VERTICAL STRAP TIE 
TO END STUDS ABOVE 
AND BELOW 
OFFSET SHEAR WALL 
Figure 65 
INTERIOR SHEAR WALL 
TO REDUCE DIAPHRAGM 
LENGTH 
PLAN 
Figure 66 
Where horizontal diaphragm ratios are exceeded, interior 
shear walls are needed to reduce the diaphragm ratio. 
See Figure 66. Because interior shear walls are permanent 
and may interfere with flexibility in modifying floor layouts, 
care should be taken in determining their locations. 
When needed, interior shear walls should be walls that are 
natural separations such as garage walls or other walls regarded 
as permanent and should have a minimum number of openings. 
Plumbing walls should be avoided for use as shear walls. 
The reasons for avoiding torsional 
rotation of buildings has been previously 
discussed. In equalizing the length of 
shear walls on all sides of a building, it 
is important to remember that the 
difference in stiffness in long and short 
walls is not directly proportional to the 
lengths of the walls. Equivalent stiffness 
of shear walls cannot be obtained by 
providing two separate 8' lengths of wall 
along one side and one 1 6' length along 
the other. Shear walls should not be 
spaced more than a prescribed distance 
apart (varies by seismic risk area, see 
Section 1 4 BUILDING CODES). Intermediate 
shear panels will be needed in long :4 
exterior wall lines. 
Shear walls should extend continuously 
from foundation to roof line in 
single-story buildings and from I \ OF 
foundation to floor line and floor line to 
roof line in two-story buildings. In 
two-story construction, it is not 
necessary for the shear walls to line up Figure 67 
one above the other, but such continuity 
is encouraged to increase the stiffness 
of the wall. See Figures 65 and 68. If 
the walls in the top story are offset 
from the walls below, the overturning 
forces in the end studs or posts of the 
wall above must be carried down through 
the wall framing below to the foundation. 
The end studs could be located above a 
header, but special precautions must be 
taken to secure the studs to the header 
and the header to its supporting framing. 
Cripple studs should be placed under 
each end of the header. The studs 
supporting the header should be tied to 
the sill plate with framing clips or a 
hold-down. 
PANEL EDGE NAILED TO NAILED TO DOUBLEND 
WALL TOP PLATES AT STUDS ABOVE AND BELOW 
ROOF & SECOND FLOOR EACH END OF WALLUNE, 
SILL PLATE AND END 
STUDS 
SHEAR WALL 2 STORY 
HIGH SEISMIC RISK AREA 
Figure 68 
Shear walls should be solidly sheathed with limited 
openings for doors or windows. Small penetrations for 
vent openings are permissible, but there should not be 
more than one opening for every eight feet of wall 
length. Penetrations or openings should be avoided in 
4'-0" long shear walls. Doors and windows should be 
centered in a wall, where possible; but, in any case, 
the edge of any opening should not be positioned 
within sixteen inches (16"). of the vertical edge of a 
shear wall. The wall should extend a minimum of two 
feet eight inches (2'-8") beyond the other vertical edge 
of an opening. Wherever possible, the wall sheathing 
should continue above and below an opening. See 
Figure 69. In no case should openings interrupt sill 
plates or wall top plates. 
SHEAR WALL 
EACH END 
ABOVE AND BELOW 
OPENING IN WALL 
WHERE POSSIBLE 
WALL ELEVATION 
HIGH SEISMIC RISK 
Figure 69 
Cripple stud walls are sometimes used to support floor 
framing over crawl spaces, partial height basement walls, 
stepped foundations, and split-level floor framing. Cripple 
walls must be sheathed as shear walls to transfer 
earthquake forces from the walls above the foundations. 
The widths of cripple shear walls and the construction 
details should be the same as for shear walls on the 
floor above, although the individual walls can be 
offset. In no case should there be less width of 
shear wall available in the cripple wall than there 
is in the wall above. 
Four types of sheathing are permitted by code for shear 
walls. See Table No. 3 on page 39. Ideally, the same 
type of sheathing should be used throughout any level of 
any building. Sheathing should conform to the prescriptive 
requirements of applicable building codes. 
1) Wood Structural Panel (plywood or oriented strand board) 
for exterior and interior shear walls should be a structural 
grade with exterior glue and a minimum thickness of 3/8". 
When installed with long edges vertical, sheets should 
have vertical butt joints on the centerline of the same stud 
and the sheathing should extend from the sill plate to 
the wall top plates, rim joist or blocking. See Figures 70 
and 71. Sheets may be installed with long edges TO 
horizontal, but the horizontal edges of each sheet should 
be nailed to flat blocking between studs. Sheathing 
should be edge nailed along all edges of each sheet. 
Wider spaced nailing to intermediate studs in the field 
of each sheet is also required. For high seismic risk 
areas, a 5 ply, 1/2" thick structural grade plywood is 
recommended for best performance and for added 
stiffness to reduce damage. See Figures 70, 71, 
75 and 77. 
BLOCKING OR 
RIM JOIST NAILED 
TO SILL PLATE 
TOE NAILS 
EACH BLOCK TO 
SILL PLATE 
(RIM JOIST
TOE NAILS 
2) Diagonal sheathing, although not commonly used, is still 
permitted by code in all seismic risk areas. If used it 
should consist of 1" nominal boards installed at an angle 
of 45 degrees to the studs. The boards should be nailed 
to each stud with two 8d nails for 1x 6 boards and three 
8d nails for 8" wide boards. In addition, 6" boards must be 
edge nailed to sill plates, wall top plates and wall end studs 
with three 8d nails and 8" boards must be nailed with four 
8d nails. Butt joints of adjacent boards must be separated 
by at least two stud spaces. 
3) Gypsum board may be used in all seismic risk areas, but 
experience from the Northridge Earthquake indicates that 
gypsum board should not be used in high seismic 
risk areas unless significant damage in the event of a 
strong earthquake is considered acceptable. The wall SF 
board may be applied with the long dimension parallel TCFC 
or perpendicular to the studs with flat blocking provided 
for all unsupported edges. Although gypsum board is 
discouraged in areas of high seismic risk, it is considered 
adequate as sheathing for shear walls in moderate and low 
seismic risk areas. See Table No. 3. For high and moderate 
seismic risk areas gypsum wall board sheathing should only 
be used on very long walls in order to keep stresses low. 
It is recommended that at least 50% of any exterior wall 
should be sheathed and the minimum length of each shear 
panel should be 8'-0". 
Figure 70 
SHEAR WALL 
Figure 71 
4. Stucco applied over metal lath nailed directly 
to the studs can also be used to resist 
earthquakes. In high seismic risk areas, self-furring 
lath may not be reliable. 
Lath should be nailed to the studs, sills and 
wall top plates. Applying the lath with staples 
is not recommended in high seismic risk areas. 
In the Northridge Earthquake, it was noted that 
where stucco was used with lath or furring 
applied directly to the studs extensive damage 
resulted from the earthquake shaking. Where 
stucco is used in high seismic risk areas, it is 
recommended that plywood or oriented strand 
board be used on shear walls with the lath 
applied to the face of sheathing. Metal lath can 
be nailed directly to the face of studs on 
portions of the walls not sheathed. 
high seismic risk areas, the overall performance 
a building can be improved by continuing the 
sheathing across the entire wall from end to end. 
The sheathing should continue above and below 
window and door openings. See Figure 69. The type 
of sheathing should be uniform throughout. Plywood 
or oriented strand board is recommended. 
Proper nailing of the sheathing is very important. 
Only nail types specified in building codes should be 
used and substitution of sinker or cooler nails for 
box or common nails is not permitted. 
guns should be adjusted to prevent overdriving and 
damaging the sheathing. Edge distances and nail 
spacing should be maintained. In high seismic risk 
areas, staples should not be substituted for nails 
unless staples have been tested for use with the 
specific application. 
Nailing 
Two methods are available for bracing steel stud 
shear walls. Conventional practice is to use light 
gage steel diagonal strap bracing. See Figures 78 
and 80 for wall bracing and Figure 79 for bracing 
at garage door openings. The straps should be in 
an "X" configuration or diagonally opposing each 
other with the straps being one piece from the sill 
plate to the wall top plates. Straps are secured to 
light gage steel gusset plates with sheet metal 
screws The straps should be attached to the studs 
at each stud crossing. Plywood sheathing can also 
be used over steel stud framing. Screws must 
be used to fasten the plywood to the studs and 
plates. Spacing and edge distances should be 
the same as for nails. 
In the discussion of seismic resistant 
systems, it was noted that shear walls may 
tend to lift up at corners when resisting 
earthquake loads. To prevent this, the end 
studs or posts of shear walls should be 
anchored to the foundation with hold-down 
devices. See Figure 72. Hold-down anchors 
are usually needed at ends of shear walls 
where walls run parallel with the joists or 
rafters. Where bearing loads on the walls 
are sufficient to keep the walls from lifting 
at their ends hold-downs are not required. 
Figure 72 
Several types of hold-down anchors are 
available and the types used should be 
based on the amount of uplift expected. 
i.e. short shear walls in high seismic risk 
areas need stronger devices. The most 
effective hold-down devices are either 
bolted or screwed to posts and bolted to 
the foundations. Where used they should be 
provided at each end of a shear wall. 
Hold-down bolts should be retightened just 
before closing in the walls. Other 
hold-down devices are available that can 
be embedded in the foundation and nailed 
to the end studs or posts. Strap 
hold-downs are desirable for all shear walls 
but can be omitted in areas of low seismic 
risk or as noted above. See Figure 76. 
An attached garage on the side or end of 
a house may present a special problem as 
narrow wall elements on each side of the 
garage door opening may not function 
effectively as shear walls and will not, in 
most cases, meet height to width ratio 
requirements. To prevent rotation of the 
garage roof diaphragm special construction 
of the walls perpendicular to the garage 
door opening is required or a rigid steel 
frame can be put across the open front. 
See APPENDIX- pages (A4) and (A5). If a 
shear wall is available adjacent to or in 
line with the garage door opening, it may 
be used to stabilize the garage and must 
be constructed as a conventional shear wall 
with earthquake loads transferred to the 
wall by continuous top plates or other 
collector or drag strut members. See 
Figure 73. 
Where walls parallel to the roof framing do 
not extend uninterrupted to the roof 
sheathing they may require lateral support 
at the level of the top plates. See Figure 
74. This detail is applicable primarily in 
high seismic risk areas, but should be 
considered for all seismic risk areas where 
wind loads are a concern. For gabled roofs, 
where this condition is most likely to occur, 
it is better to use full length studs from 
foundation to the roof plate line. 
END NAILED 
ROOF TRUSS 
OR FRAMING 
AT END WALLS 
NOT STEEPER 
THAN 2:1 
SHEET METAL 
FASTENER 2x6 
DIAGONAL TO 
WALL TOP PLATE
2x BLOCKING AT 
2x6 DIAGONAL 
STRUTS 0 48"O.C. 
TO PROVIDE 
LATERAL SUPPORT FOR 
TOP OF WALL. 
Figure 74 
ROOF SHEATHING NAILED TO 
COLLECTOR WITH BOUNDARY 
NAIL SPACING FOR FULL 
LENGTH OF COLLECTOR EA. 
SIDE OF RIDGE 
SPUCE COLLECTOR (RIDGE 
DBL TOP PLATE HOLD-DOWN STRAP-WRAP 
(COLLECTOR AROUND BLOCKING AND NAIL 
SHEAR WALL TO BLOCKING AND STUD 
EACH BLOCK TO 
SHEAR WALL LATE 
STRAP TO ENGAGE 
BLOCKING IN TWO 
RAFTER SPACES ADJACENT 
TO OR 
WITH OPENINGGARAGE 
OPENING 
Figure 73
Table No. 3 Maximum Floor and Roof Diaphragm and Wall Aspect Ratios 
Sheathing Seismic L/W H/W 
High 4
Plywood Moderate 4* 
ROOF DIAPHRAGM 
LENGTH (SPAN) low 4 
DIAPHRAGM O. High4
ROOF Oriented Strand Moderate 
DIAPHRAGM ~Board Low 4 
WALL High 2 
Diagonal Sheathing Moderate 2 
ROOF 
RATIO =L/W Lo 2 
ROOF DIAPHRAGM Straight Sheathing Low 2 
High 4* 
FLOOR 
LENGTH Plywood Moderate 4* 
High 4* 
WALL H Oriented Strand Moderate 4* 
Board 
Low 4 
High 2 
IARATIO L/W Diagonal Sheathing 
DIAPHRAGM Moderate 3 
W DTH V 
FLOOR DIAPHRAGM Straight Sheathing Low 2 
High 2 
Wood Structural Panel 
Plywood Moderate 2 
SHEAR WALL 
HEIGHT 'H' Oriented Strand Board Lw3
Low 
High 2 
Moderate 2 
Low 3 
RATIO = H/W Moderate 2 
SHEAR WALL Diagonal Sheathing 
SHEAR WALL 32 
* All edges blocked. Reduce to 3 
for unblocked edges. 
5/8" ANCHOR BOLTS FOR 
HIGH AND MODERATE SEISMIC RISK AREA. 
1/2"ANCHOR BOLTS FOR 
LOW SEISMIC RISK AREA. 
WOOD STRUCTURAL PANEL 
SHEATHED SHEAR WALL 
Figure 75 
EDGE OF SHEET (BOUNDARY) 
NAILING TO BLOCKING AND 
WALL TOP PLATE 
SHEATHING BUT 
JOINTS NAILED TO 
SAME STUD 
DOUBLE STUDS EACH 
END OF SHEAR WALL 
HOLD-DOWN STRAP 
EACH END OF 
SHEAR WALL 
BEND STRAP AND 
EMBED IN FOOTING 
STRAP HOLD-DOWN 
Figure 76 
Figure 77