13
OFFSET ELBOW INSTALLATION
DuraTech allows for the use of one pair of
30° Elbows (measured from the vertical) for
chimney sizes 10” - 24”. A 30° Elbow is the
largest that can be used in an offset from
vertical. A 30° Elbow may not be combined
with another elbow to make a steeper offset
(e.g. two 30° Elbows are not allowed to be put
together to form a 60° elbow from vertical).
Avoid Elbows if possible, since a totally vertical
chimney is more efficient. When Elbows
are necessary to avoid obstructions such
as rafters, ridgepoles, or joists, you are only
allowed to use 1 pair of Elbows in any one
chimney system.
1. Attach Elbows:
Attach Elbow to Chimney
Section or other Elbow by mating the male
and female ends with each other and using
the (6) sheet metal screws provided. Attach
one Elbow to the Chimney Section below,
and align it for the offset. Refer to
Table 3
to determine the required offset length and
attach an appropriate length (or lengths) of
Chimney Section(s) above the Elbow. For
each Chimney Section in the offset, an Elbow
Strap must be used to support the weight of
that pipe section. The total offset distance can
not exceed 50% of the total chimney height.
Attach the second Elbow above the Chimney
Section to complete the offset
(Fig 15)
.
2. Secure Offset:
Place the Elbow Strap’s
band around the angled portion of the top
Elbow, then tighten the nut and bolt until the
clamp is firm. Wrap the Elbow Strap end over
an adjacent joist or rafter and secure it with at
least two 8-penny nails or #8, 1-1/2” screws.
Do not add more Chimney Sections until
the Elbows are supported. Be sure that the
chimney remains vertical
(Fig 15)
.
Figure 15
CHIMNEY
SECTION
RISE
(INCHES)
ELBOW
ELBOW STRAP
OFFSET
(INCHES)
