12/31/2015
Is it that simple?
Simplified Wall
Bracing
Keep it Simple
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Goal
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Simplified Wall Bracing
Offer the majority of the country an easy
approach as a subset of the “classic” method.
Cannot mix simplified with classic
≤ 115 mph wind
Simple houses = simple solutions
Simple solutions = less flexibility
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Simplified Wall Bracing Topics
■ Prerequisites
Prerequisites
■ Methodology and materials
■ Bracing units
■ Bracing distribution
■ Classic wall bracing carry-overs and
comparisons
Minimum Building Conditions
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Prerequisites R602.12
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Prerequisites R602.12
1. Maximum of 3
stories above
a solid
foundation or
basement.
2. Floors may not
cantilever more
than 24” beyond the
foundation or
bearing wall.
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Prerequisites R602.12
Prerequisites R602.12
3. Wall heights cannot
exceed 10’.
4. Eave to ridge
height cannot
exceed 15’.
bigger “sail area”
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Prerequisites R602.12
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Prerequisites R602.12
6. Wind speed ≤ 130 mph,
5. Gypsum board min.
½” or equivalent
(e.g., wood paneling)
on interior side of
bracing.
in Exposure B & C.
< 130 mph
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Prerequisites R602.12
Prerequisites R602.12
7. Seismic Design Category A, B or C
(no townhouses in SDC C).
8. Cripple walls and wood framed
walls below the first floor:
townhouses
■ Prohibited in two-story
■ Permitted in one-story
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Quiz Question
Quiz Question
The maximum height of a wall when
using Simplified Wall Bracing is:
□
□
□
□
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True or False:
An unfinished
detached garage
can be braced
using Simplified
Wall Bracing.
9 feet
10 feet
12 feet
False: An unfinished garage cannot be
constructed unless there is gypsum board or
equivalent on the opposite side of all bracing.
15 feet
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Rectangle Topics R602.12.1
■ Circumscribed rectangle
■ Projections
Methodology & Materials
■ Open structures
■ Size of the circumscribed rectangle
Circumscribed Rectangle
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Circumscribed Rectangle R602.12.1
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Circumscribed Rectangle R602.12.1
Don’t include…
Draw a rectangle
around the
outside of the
structure.
■ Open structures: porches, decks, carports
Sunroom
■ Chimneys
1st floor
Deck
Garage
1st floor
Circumscribe around all offsets and
projections, including sunrooms and
attached garages.
Carport
Porch
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Circumscribed Rectangle R602.12.1
Circumscribed Rectangle R602.12.1
Rectangles may be different for each floor.
floor
11ststfloor
2nd floor
Addition
Rectangle can also
apply to a new
addition to an
existing house.
Existing
House
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Circumscribed Rectangle R602.12.1
Max 60 feet
Circumscribed Rectangle R602.12.1
60’
Max 60 feet
20’
Maximum length of
either side of the
rectangle is 60’.
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1st floor
Maximum ratio:
1st floor
long side = 3:1
short side
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Circumscribed Rectangle R602.12.1
Sheathing Materials R602.12.2
50’ x 38’
Example:
36'-0"
8'-0"
14'-0"
10'-4"
3'-0"
10'-0"
3'-0"
3'-0"
2'-0"
3'-6"
5'-0"
3'-5"
4'-9"
2'-8"
3'-0"
13'-6"
GARAGE
22'-0"
KITCHEN
Min. 3/8” OSB or plywood
9'-6"
28'-0"
15'-4"
BREAKFAST
FAMILY RM
12'-8"
LIVING RM
Min. 1/2” structural fiberboard
4'-0"
5'-1"
DINING RM
2'-4"
2'-4"
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Sheathing Materials R602.12.2
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Quiz Question
True or False: The circumscribed rectangle
below is correctly drawn.
Cannot mix OSB and structural fiberboard on
the same house.
Deck
1st floor
Carport
Porch
False: Open structures, such as carports are
not included in the circumscribed rectangle
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Quiz Question
Which is not a bracing material for Simplified
Wall Bracing?
□
□
□
□
Bracing Units
Structural fiberboard
Plywood
3’ or 4’
OSB
Gypsum board
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Bracing Units R602.12.3
Bracing Units R602.12.3
BU length depends on application:
A “Bracing Unit” (BU) must be:
Fully sheathed (3’ BUs)
■ Full height
sheathing
without
openings
Intermittent (4’ BUs)
OSB
■ No vertical or
horizontal
offsets
SFB
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Multiple Bracing Units R602.12.3.1
Bracing Units R602.12.3
No mixing of materials or applications
Fully sheathed (3 BUs)
Multiple bracing units:
Intermittent (4’ BUs)
OSB
■ Wall panel lengths longer than the
minimum length – full credit
■ Wall panel lengths less than the minimum
length – no credit
SFB
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Multiple Bracing Units R602.12.3.1
Multiple Bracing Units R602.12.3.1
Actual total number of BUs
Wall panel lengths longer than the
minimum length – full credit
# B.U. = Actual length ÷ 3’ (or 4’)
Section 1
13’ ÷ 3’ = 4.33 BU
13’
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+
+
1 BU 1.3 BU 2 BU
2.5’
+
1.8 BU
Actual BUs = 6.1
Section 2:
2.5’ ÷ 3’ <1.00
Therefore = 0 BU
Calculate each side of the
rectangle independently
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Required Number of BUs R602.12.4
Required Number of BUs R602.12.4
Length of long side defines the # BUs on the
short sides and vice versa
Tabular value of required BUs:
Bigger sail area
of long side
More
wall bracing
required on
short side
■
Number applies to each side of rectangle
■
Round rectangle size up to next unit of 10’
■
No interpolation allowed
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Required Number of BUs R602.12.4
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Required Number of BUs R602.12.4
Rectangle: 50’x38’
Example:
11.6’
50’ x 38’
36'-0"
8'-0"
14'-0"
10'-4"
3'-0"
10'-0"
3'-0"
3'-0"
2'-0"
3'-6"
5'-0"
3'-5"
4'-9"
2'-8"
3'-0"
13'-6"
KITCHEN
GARAGE
22'-0"
FAMILY RM
9'-6"
28'-0"
15'-4"
BREAKFAST
12'-8"
LIVING RM
4'-0"
5'-1"
DINING RM
2'-4"
2'-4"
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5 BUs on each long side,
6 BUs on each short sides
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Required Number of BUs R602.12.4
Required Number of BUs R602.12.4
Facing side of the rectangle
Right
Right
Left
Top
Left
‘Partially exposed’ and ‘not-exposed’
wall segments may also apply to a
side of the rectangle
Partially exposed
wall segment
Bottom
Not-exposed
wall segment
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CS-PF, Figure R602.10.6.2
Special wall construction: CS-PF
Special Wall
Construction
■ Contributes 0.5 BU per panel
■ Permitted only when fully sheathing
CS-PF, PFH, PFG, CS-G
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PFH, Figure R602.10.6.2
PFG, Figure R602.10.6.3
Special wall construction: PFH
Special wall construction: PFG
■ Contributes 1.0 BU per panel
■ Contributes 0.75 BU per panel
■ Permitted in all sheathing applications
■ Permitted in all sheathing applications
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CS-G, Table R602.10.4
Quiz Question
Special wall construction: CS-G
How many bracing units are on the first floor
front wall of the house below?
■ Contributes 0.5 BU per panel
■ Permitted only when sheathing is placed
over entire structure
□
□
□
□
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2.5
4.33
5.33
6.67
3’
5’ 2’
2’ 5’3’
1 + 1.66 + 0 + 0 +1.66+ 1 = 5.33’
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Quiz Question
Quiz Question
How many bracing units are required on the
long side of the rectangle below?
First of two-story with 15’ eave-to-ridge
height
□
□
□
□
First of two-story with 15’ eave-to-ridge height
51’
4
5
□
□
□
□
41’
6
7
4
5
6
7
41’
51’
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Quiz Question
Match the portal frame with the number of
equivalent bracing units.
PFH
1.0
PFG
0.5
CS-PF
0.75
Bracing Unit Distribution
Three Rules
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Distribution Rules R602.12.5
Distribution Rules R602.12.5
2. BUs shall be ≤20’ apart edge to edge.
1. BU shall be placed on the perimeter of the
building and begin within 12’ of all wall
corners.
≤12’
≤12’
Left
≤12’ ≤12’
≤20’
Left
≤12’
No bracing on the inside of the house!!!
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Distribution Rules R602.12.5
Quiz Question
3. Wall segments > 8’ long must have at least
one BU.
True or False:
A wall with a length of 8 feet is permitted to
have no bracing units.
True
≤8’
≤8’
Conversely, wall segments
≤ 8’ long do not require a BU.
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Classic Wall Bracing Carry-overs
■ Bracing connections at roof construction.
■ Masonry stem wall reinforcement.
“Classic Wall Bracing”
Carry-overs and
Comparison
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Nailing Precision
Comparison
Simplified Wall
Bracing
Wind
≤ 90 mph
Circumscribed
Methodology
Braced wall lines
rectangle
Minimum length of Minimum number of
Required bracing
bracing (feet)
bracing units
8 materials, 14
Methods and
2 materials, 4 classic
methods (4
materials
narrow methods
narrow)
Maximum size house
Unlimited
60’ x 60’
Corner/End of BWL Return panel or
None
CS/fully sheathed 800 lb hold-down
Maximum wall ht
12’
10’
Criteria
Classic Wall
Bracing
< 110 mph
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90 mph, Exp B,









40’
24’
24’
1.67

40’
8:12
8:12 eave ht = 8’
3.5’
4.3
5.5
10.6
Rectangle = 40’ x 24’
9’ CEILING, CONTINUOUSLY SHEATHED WITH OSB
Determine if house complies

1.2
1.5
1.8
3.5
8.0

Compare Classic and Simplified
60’ x 38’
Rear wall of house:
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2
3
4
Classic method
Simplified method
Bracing required
4.1 x .95 x .94 = 3.7’
Bracing required
2 B.U.s @ 3’ each = 6’
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









60’
38’
1.6

38’









60’
38’
1.6

38’
60’
60’
3.0’ 1.0
5.3’ 1.8
3.5’ 1.2
19.3’ 6.4
10.4


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








60’
38’
38’
1.6










1.6
38’

60’
3.0’ 1.0 3.0’1.0 4.8’1.6
4.0’ 1.3
5.3’ 1.8 4.0’ 1.3 11.8’ 3.9
3.5’ 1.2 3.0’ 1.0
CSPF0.5
19.3’ 6.4
CSPF0.5
10.4
5.6
5.6

 
60’
38’
60’
3.0’ 1.0 3.0’ 1.0
4.0’ 1.3
5.3’ 1.8 4.0’ 1.3
3.5’ 1.2 3.0’ 1.0
CSPF0.5
19.3’ 6.4
CSPF0.5
10.4
5.6

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
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

 

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Compare Classic and Simplified









B C
12.0’
12.0’
3.0’ 1.0 3.0’ 1.0 4.8’1.6 3.7’ 1.2
4.0’ 1.3
5.3’ 1.8 4.0’ 1.3 11.8’ 3.9 3.7’ 1.2
12.0’ 4.0
3.5’ 1.2 3.0’ 1.0
7.0’ 2.3
CSPF0.5
19.3’ 6.4
4.0’ 1.3
CSPF0.5
10.4
5.6
5.6
10.1


 
 
 
5 B.U.s
2
3
7 B.U.s
60’
D
1
7 B.U.s
38’
2.8’
23.4’

5.7’
3.5’
1.6
16.2’
60’
38’
A
5 B.U.s
Required by Classic Method
Required by Simplified Method
Back = 14.8'
Front = 12'
Left = 19.7'
Right = 29.1'
Back: 5x3' = 15'
Front: 5x3' = 15'
Left: 7x3' = 21'
Right: 7x3' = 21'
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Don’t be overwhelmed
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