DuraVent DuraStack Installation User Manual
Page 7
CHIMNEY WEIGHT
Chimney.weight.is.given.in.pounds.per.foot.of.chimney.for.each.diameter...
It.is.important.to.know.the.weight.of.the.chimney.section.for.chimney.
support. or. guiding.. Chimney. weight. (table 8). along. with. maximum.
chimney.height.(table 6).are.necessary.to.calculate.the.proper.anchor.
strength.needed.with.wall.supports.(WS),.Anchor.Plate.(AP).supports.
and.Suspension.Bands.(SB).
NOTE:.DIAGRAMS.&.ILLUSTRATIONS.ARE.NOT.TO.SCALE.
7
Example: Model DIS, 6” diameter section of 25 feet in length from table 8,
weight in lb/ft = 8. Total weight 8 x 25 = 200 lbs
CHIMNEY 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.
2.. If.the.stack.above.the.roof.does.not.exceed.dimension.H,.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
7).
3.. For.stack.height.above.the.roof.that.needs.guying.or.bracing,.a.support,.
a.small.length.and.a.expansion.length.must.be.installed.near.the.roof.
level.to.absorb.the.thermal.expansion.and.minimise.this.effect.on.the.
guy.wires.or.brace...
4.. When.using.guy.wire,.the.cable.must.be.slightly.slack.or.loose.to.allow.
thermal.expansion.
5.. When.using.rigid.bracing,.the.maximum.vertical.height.between.sup-
ports.must.be.reduced.to.5’.to.compensate.thermal.expansion.
Figure 7 - Maximum freestanding chimney height
* If Dimension “H” exceeds the
value in table 7, use bracing or
cable guying to stabilize chim-
ney section above the roof. See
notes 3, 4, 5 and figure 8.
Figure 8 - Chimney height with rigid bracing or guying option
See table 7 for “H” dimensions
Support
Maximum Height
See table
H*
Guide
No guying or bracing required
Maximum
height -
See table 6
Support
Expansion Length
Guide
Support
* Cables and roof anchors
designed for 30 lb. per
sq. ft. force on chimney
projected area.
Brace
Guy Cable * tensioners and
roof anchors * (by others)
H
H
5’ MAX
CHIMNEY WEIGHT IN LB/FT
Inside diameter
Model DIS
Model DAS
5
7
4
6
8
5
8
10
6
10
12
8
12
14
9
14
16
10
16
18
12
18
20
13
20
22
14
22
24
15
24
28
19
26
30
20
28
32
21
30
34
23
32
36
24
34
38
25
36
40
27
Table 8