26
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
NOTE:
Maintain adequate spacing for expansion from the floor and
the outer band (
BSE
) that is under the floor.
NOTE:
If the maximum freestanding duct height above the Anchor Plate (
AP
), Anchor
plate with length (
APL
) or Full Angle Ring (
FAR
) exceeds that shown in the
Table 3
and
Table 4
, guying is required.
Figure 63a - Minimum Opening for flat roof
Flat Roof
”x”
Figure 63b - Minimum Opening for sloped roof
5
° to
30
°
”x”
Figure 64a - Installation of Flashing- View Top of the Roof
Figure 64b - Installation of Flashing- View under the Roof
Vent
Section
Vent
Section
Storm Collar
(SC)
Flashing (F)
Exterior Sealant
(
S375
)
Outer Band
(BSE)
Roof
Outer Band
(BSE)
GUYING AND BRACING
1. Proper guying and bracing is essential for part of the Chimney that extends above
the roof or parapet wall. The chimney at this point is subject to wind conditions and
needs special attention for proper stabilization. See
figure 65
.
2. If the chimney above the roof does not exceed dimension H in
Table 4
, no special
guying or bracing is required. However, to protect the flashing from lateral movement,
a guide must be installed at the roof level. See
figure 65
.
3. To minimize the effect of thermal expansion, good practice implies installing a fixed
support and an expansion length at the roof level.
4. When using guy wire, the cable must be slightly slack or loose to allow thermal
expansion or be equipped with tensioning springs (by others). The tensioning springs
are mandatory only when there is more than one level of guy wire needed.
5. When rigid Brace (by others) are used, the maximum distance between the last fixed
support and the band of the roof brace must be reduced to 5’ to minimize loads
induced by thermal expansion on braces and support,
6. Make sure to have a rigid structure on the roof.
The Guy Ring
(GR)
consist of half clamps installed on the inner wall flanges
of a joint
of two sections. The Clamp rings have holes at 60° apart, to have the choice of adding
guy wires (by others) at 120° (Ø5 to Ø20) or 60° apart. The guy wires are fixed to the
roof by the mean of tensioner or anchor (by others). Rigid Brace can also be used on
the Guy Ring. The Storm Collar
(SC)
is placed around the chimney and sealed to the
casing with outer joint sealant
S-375
. See
Figure 66a
for parts included in the Guy
Ring and
Figure 66b
for one installed..
Figure 66a - Guy Section Details
Figure 66b - Guy Section Installed
