LINEAR PATTERN WITH ONLY LAFITT OR MELVILLE TANDEM 90 UNITS
TANDEM
®
SYSTEM
–
9
BUILDING A RETAINING WALL
TYPICAL CROSS SECTION AND INSTALLATION PATTERN
90 mm LAFITT OR MELVILLE TANDEM WALL
A Straight Capping unit
90 mm
×
305 mm
×
400 mm
(3 9/16
"
×
12
"
×
15 3/4
"
)
B Structural units
90 mm
×
155 mm × variable (201, 268, 335 or 402 mm)
3 9/16
"
×
6 1/8
"
×
var (7 7/8
"
, 10 1/2
"
, 13 3/16
"
, 15 13/16
"
)
C Veneer units
90 mm × 67 mm × variable (201, 268, 335 or 402 mm)
3 9/16
"
× 2 5/8
"
× var (7 7/8
"
, 10 1/2
"
, 13 3/16
"
, 15 13/16
"
)
D Perforated drain 100 mm Ø (4 in) connected
E Geotextile membrane
F Granular base 0-20 mm (0-3/4
"
)
compacted 300 mm (12
"
) min .
G Buried depth 150 mm (6
"
) min .
H Clean stone 20 mm (3/4
"
)
I Starter unit
90 mm × 200 mm × 400 mm
(3 9/16
"
× 7 7/8
"
× 15 3/4
"
)
INSTALLATION PATTERN
A
D
I
C
B
H
E
F
0° or 9°
300 mm
(12 in) min .
G 150 mm (6 in) min .
900 mm (36 in) max
300 mm (12 in) min .