COMMUNITY DEVELOPMENT SERVICES
3801 W Van Giesen, West Richland 99353
Phone: 509-967-5902 Fax: 509-967-2419
LATERAL BRACING FOR 2-STORY HOUSE
NOTE:
DAYLIGHT BASEMENT WALLS ARE CONSIDERED 2-STORY CONDITION FOR
BRACING PURPOSES; THE DAYLIGHT BASEMENT IS THE "FIRST FLOOR" CONDITION.
FIRST FLOOR OF A 2-STORY HOUSE
1. FOUR FOOT SOLID WALLS AT ALL CORNERS AND AT EVERY 25 FEET ALONG ANY
WALL LINE. (see options on 1-story house handout if you don't meet this requirement ).
2. BRACED WALLS MUST BE AT THE CORNERS. (see options on 1-story house handout if you
don't meet this requirement).
3. 45% (or 60% for Energy Brace or Fiber Brace walls) OF ANY WALL LINE MUST BE SOLID,
BRACED WALLS (AND A PANEL EVERY 25 FEET).
Add up all lengths of all braced panels (those that count as bracing) along the wall. This must be
equal to or greater than 45% (or 60% for other than OSB) of the entire wall length. If you do not
meet this requirement, the only option is for an engineered design.
4. EXTERIOR WALL LINES (OR TOGETHER WITH SOME INTERIOR WALL LINES) NOT MORE
THAN 25 FEET APART.
(see options on 1-story house handout if you don't meet this
requirement).
SECOND FLOOR OF A 2-STORY HOUSE
5. FOUR FOOT SOLID WALLS AT ALL CORNERS AND AT EVERY 25 FEET ALONG ANY
WALL LINE (and 20% MUST BE BRACED WALLS—30% FOR Fiber or Energy Brace).
If you can't meet the requirements for 4 foot panels on the 2nd level, try:
a.
If the house can be made ALL OSB or PLYWOOD, then panels as small as 24" can
possibly be used depending on the windows—follow all of Table R602.10.5
b.
Portal frames CANNOT be used on a 2nd level
c.
Alternate Braced walls CANNOT be used on a 2nd level.
d.
Engineered lateral design is often required because of no 4 foot panels on 2 nd level
walls.
6. FOUR FOOT SOLID WALLS MUST HAVE A MATCHING PANEL BELOW AT THE FIRST
LEVEL. (with the exception of up to 1 foot of the upper panel can be over a window below).
7. OTHER CONDITIONS OF "IRREGULAR" BUILDINGS APPLY TO WEST RICHLAND
BECAUSE OF SEISMIC ZONE D1 (these limitations mean that an engineer may often be
required).
a.
NO openings between floors—such as balcony areas—with a dimension of greater than 12
feet.
b.
NO cantilevered condition braced walls—some exceptions when floor joists are solid
lumber.
c.
Upper level CANNOT have "footprint" different than lower level—with exception for 6 foot
dimension in any direction.
d.
NO changes in floor level within the same floor (no sunken rooms—doesn't apply to 1st
level).
IF MORE THAN 25’ NEED ANOTHER
C
C
HOUSE
OFFSET SOLID WALLS
CAN BE USED (4’ MAX.
OFFSET)
BRACED WALL LINE
(8’ TOTAL)
4’ OFFSET MAX
INTERIOR WALLS CAN BE USED
IF MORE THAN 25’ BETWEEN
OUTSIDE WALLS
DIRECTION OF WIND OR SEISMIC
4’ SOLID
WALL
(or use interior walls)
(8’ TOTAL)
4’ PANEL
NOT MORE THAN 25’
NOT MORE THAN 25’
4’ OFFSET MAX
BRACED WALL LINE
C
NOT MORE THAN 25’
C
GARAGE
4’ PANELS OR ALTERNATE BRACED
PANELS & HOLD DOWNS
DIRECTION OF WIND OR SEISMIC
NOT MORE THAN 25’
GARAGE
BRACED WALL LINE
BRACED WALL LINE
INTERIOR WALLS CAN BE USED
TO MEET THE 25’ REQUIREMENT
HOUSE
FLOOR PLANS
REPRESENTS 4’ BRACED PANEL
THE BUILDING MUST BE EVALUATED IN BOTH DIRECTIONS. IF 4 FOOT SOLID
WALLS ARE NOT AVAILABLE, THEN SEE OPTIONS FROM HANDOUTS.
BRACED WALL LINE
NOT MORE THAN 25’