Think Brick Manual 12 · per metre run
Design of a freestanding brick fence or garden wall for wind: self-stability, pier spacing and pier capacity, following the Manual’s steps with the working shown.
Input — you edit
Derived from inputs
Design result
01
Inputs
Site, wall, return walls, piers and materials1
Site & wall
Step 1 · AS 4055m
2
Wall type
Step 4 · Table 4
3
Return wall at end
Table 8 · §5.4.3Include return wall buttressingoptional
4
End condition at pier
Step 6 · Fig. 25
Pier spacing
Step 7 · §5.4.1(c)m
Maximum allowed Sp,max (working step 6)
—m
6
Lateral support system
Step 8 · Tables 6 & 7
f′m — masonry strength, 1c:1L:6s mortar AS 3700 Table 3.1
5.4MPa
Pier systemManual 12 table
Pier type — Table 6, Fig. 3
Pier type — Table 7, Fig. 4
Bar diameter — 4 bars per pier
Type E — size and reinforcement
Pier size wp × tp
Reinforcement
Type F — size and reinforcement
Pier size wp × tp
Reinforcement
Type G — size and reinforcement
Pier size wp × tp
Reinforcement
02
Results
Design checks — demand against capacityCheckDemandCapacityUtilisation
03
Working
Manual 12 steps 2–10, each with the formula, the substituted numbers and its table or clause•
Wall elevation
not to scale2
Wind pressure
Table 1Aspect ratio
l / H
—
—
Design wind pressure Table 1
p from wind class and l / H
—
—kPa
3
Overturning moment & shear
Tables 2 & 3Overturning moment at base Table 2
M = pH2 / 2
—
—kN·m/m
Base shear Table 3
V = pH
—
—kN/m
4
Stability moment of wall panel
Table 4 · Table 8Panel stability moment Table 4
Mr = 0.9mt2H / 2
Self-weight restoring moment, read from Table 4
—
—kN·m/m
Return wall buttressing Table 8 · §5.4.3
—
—kN·m/m
Total stability moment
Mr,total = Mr + Table 8
—
—kN·m/m
5
Does the wall need lateral support?
§5.4.1(a)Additional moment required
Mreq = max(0, M − Mr,total)
—
—
—kN·m/m
6
Maximum pier spacing
Table 5 · Fig. 2Maximum pier spacing
Sp,max = √( k · Mh / (pH) )
—
—
—m
7
Moment & shear at the pier
§5.4.1(c)Design moment at pier
M* = Mreq × Sp
—
—kN·m
Design shear at pier
V* = V × Sp
—
—kN
8
Pier capacity
Tables 6 & 7—
—
Width wp
—
Depth tp
—
Wall leaf thickness tw
—
Reinforcement
—
Brick strength f′uc
15 MPa
Bending capacity φM
—
Shear capacity φV
—
—
No pier selected — choose Table 6 or Table 7 in input 6 to see its capacity.
9
Footings
§5.5 · AS 2870Min. strip width — wall centred on footing
—mm
Min. strip width — wall off-centre
—mm
Min. concrete strength f′c
20MPa
Min. cover to reinforcement
50mm
10
Construction details
§4Mortar (piers & panels)
1 cement : 1 lime : 6 sand
Grout mix (hollow piers)
1 cement : 2 sand : 4 aggregate
Wall tie spacing (twin-leaf)
400 × 400 mm
DPC below coping
Membrane type
Control gaps (low-e brick)
Not required
Brick durability
AS 3700 Table 5.1