Offset Elbow Installation | Hearth and Home Technologies BIR50-B

I. Offset Elbow Installation

A 30° Elbow (measured from the vertical) is the largest that can be used in an offset. 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.). Avoid Elbows if possible. 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 2 pair of Elbows in any one chimney system. Horizontal runs of chimney violate building code and are not allowed.

•Attach elbows

Attach elbow to chimney section or other elbow by ating the male and female ends with each other and using four sheet metal screws provided. Attach one elbow to the chimney section below, and align it for the offset. Determine the required offset length and attach an appropriate length (or lengths) of chimney section(s) above the elbow. Attach the second elbow above the chimney section to complete the offset (Figure 8.6).

•Secure offset

Use an elbow strap to secure the offset. Secure the elbow strap’s band to chimney around the upper 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 two #8, 1-1/2” screws. Add additional elbow straps for each section of chimney in the offset (Figure 8.7). Every chimney section in the offset must be supported. Do not add more chimney sections until the elbows and offset are supported. Be sure that the chimney remains vertical.

J. Supplementary Support & Stabilizer

Install a supplementary support if total chimney height is greater than 50-feet, or if the fireplace manufacturer re- quires it. If additional support is needed, install one or more supplementary supports which can each support 25-feet of chimney (Fig. 8.8).

•Clamp the supplementary support band around the pipe using the nut and bolt provided, and anchor the support to nearby building framing.

•Always maintain the 2” clearance to combustibles from the chimney pipe. A stabilizer is available and may be required by some fireplace manufacturers to keep the chimney vertical and help maintain clearances to combustibles within a chase.

•Clamp the stabilizer to the pipe using the nut and bolt provided, and secure legs to nearby framing using plumber’s tape or guy-wires (Fig. 8.9).

Note: The stabilizer does not support the weight of the chimney, it is only used to keep chimney centered within a chase.

Install supplementary	Each supplementary
support if height exceeds	support holds up to
50 ft or if required by	25 ft. of chimney
fireplace manufacturer
	Maintain 2 in. clearance
	from chimney to framing

Elbow Strap

30° or 15°

Elbow

Figure 8.6

Elbow Strap

1 per

Section

Figure 8.7

Figure 8.8

Chase

Frame

Stabilizer

Plumbers

Tape

Figure 8.9

Heatilator • Birmingham BIR50-B • 4059-682C• 8/12