DuraVent DuraStack Installation User Manual
Page 16

NOTE:.DIAGRAMS.&.ILLUSTRATIONS.ARE.NOT.TO.SCALE.
16
ROOF BRACE (RB)
1...The.roof.brace.is.used.to.stabilize.the.chimney.where.it.extends.more.
than.15’.above.the.roof.
2...It.consists.of.one.band.(RB).and.two.braces.(supplied.by.the.installer).
3...To.minimize.loads.induced.by.thermal.expansion.on.braces.and.sup-
port,.the.maximum.distance.between.the.last.fixed.support.and.the.
band.of.the.roof.brace.must.be.reduced.to.5’.
4...Begin.by.attaching.the.braces.to.the.band.with.supplied.bolts.and.
nuts...Next,.install.the.band.on.the.chimney.and.tighten.the.band...Fix.
the.braces.to.the.roof.at.120°...Make.sure.you.have.a.rigid.structure.
on.the.roof.
Figure 34 - Roof brace assembly
GUY WIRE (GW)
1...The.guy.wire.is.used.where.the.chimney.extends.more.than.15’.above.
the.roof.
2...It.consists.of.a.band.designed.to.receive.3.guy.wire.(supplied.by.others).
at.120°.apart.or.6.guy.wire.at.60°.apart.for.diameter.larger.than.24”..
The.guy.wires.are.fixed.to.the.roof.by.mean.of.tensioner.and.anchor.
(also.by.others).
3...When.installing.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.
4.. To.minimize.the.effect.of.thermal.expansion,.good.practice.implies.
installing.a.fixed.support.and.an.expansion.length.at.the.roof.level.
(see.Figure 35.’guy.wire’).
Figure 35 - Guy Wire
1-1/4” Rigid galvalume tube
or 1-1/2” x 3/16” angle iron
(by others)
Fixed support
5’ Max
H
120°
Guy Cable * tensioners and
roof anchors * (by others)
Guy wire band (GW)
Fixed support
H
Expansion length
* Cables and roof anchors
designed for 30 lb. per
sq. ft. force on chimney
projected area.