Instructions / Assembly
®
System 1738 Installation Methods 9
Chimney Terminations
If System 1738 piping is installed through an existing 
unused chimney space, installers shall adhere to the 
following guidelines when doing such installations:
(a)  Vent pipe sizing to be as per appliance 
manufacturers’ instructions or appliance 
manufacturer’s technical manual.
(b)  NO existing non-certified vent piping shall be used 
or re-used for venting. They shall all be replaced 
with System 1738 as required.
(c)  The chimney space shall be cleaned prior to 
installation to remove any debris, creosote, or other 
material.
(d)  All recommended practices for solvent welding 
must be observed in the same manner as regular 
System 1738 installations. Refer to solvent welding 
basic principles and installation steps within this 
guide.
(e)  Multiple vent pipes are permitted in one chimney 
space as limited by the interior available cross-
sectional area. Zero clearance is permitted between 
multiples runs of System 1738 piping or other 
combustibles. (see Figure 12).
Figure 12: Chimney Termination
To Termination
Clamp to be snugly fit but allowing 
pipe travel due to expansion
Coupling to sit on riser clamp to 
support weight or section above
From Appliance
Chimney Installations
(f)  Fresh air intakes may also be installed within 
existing unused chimney spaces providing 
acceptable spacing and clearance is obtained 
at the termination as per appliance manufacturer 
requirements.
(g)  Vertical piping through the chimney space or any 
other vertical spaces exceeding 20 feet is to be 
structurally supported by use of a pipe coupling 
installed immediately above and sitting upon a 
snugly fit pipe clamp. One of these pipe coupling 
and pipe clamp combinations is to be installed 
at the entrance of the chimney space to support 
the pipe weight. The clamp at the entrance of the 
chimney is to be rigidly fixed against the wall or floor 
(see Figure 12). Should the pipe run exceed 60 feet 
inside the chimney space, please contact IPEX for 
further requirements.
(h)  It is recommended to install an air-tight seal as 
required at the chimney exit to prevent entry of 
water, snow, moisture or cold air.










