Instructions / Assembly
®
System 1738 Installation Methods10
Support and Restraint Spacing
(a)  System 1738 PVC systems must be supported 
horizontally at a maximum of every 5 feet. 
(b)  Supports to be used on System 1738 pipe shall be 
suitable for use on plastic pipe and shall not be 
tightly clamped onto the pipe to allow for possible 
expansion/contraction movement. Pipe clamps, 
hangers, metal strapping or equivalent shall not 
have sharp edges or fulcrum points which might 
damage the System 1738 pipe over time. 
  Strapping shall meet the following requirements 
• 1/2" strapping - 22 gauge steel 
• 3/4" strapping - 28 gauge steel
  Strapping or equivalent shall be fixed to supporting 
structure (e.g. floor joists or cross members) using 
typical framing nails or screws.
(c)  Changes in direction (e.g. 90° elbows) should be 
supported as close as practical to the fitting to 
avoid introducing excessive torsional stresses 
into the system. This is especially important for 
vertical 90
o
 bends. If support is being applied to 
the fitting, then the fitting must be free to move 
during expansion and contraction of the venting 
system.  
(d)  In order to adequately support the weight of 
vertical vent pipe, a pipe anchor or support shall 
be installed at the first floor penetration and every 
second floor thereafter with a System 1738 coupling 
installed immediately above it. Securely fasten pipe 
anchors or supports to the building structure. Pipe 
anchors or supports used for this purpose shall be 
suitable for use with plastic pipe. These anchors 
or supports shall be snugly fastened to the vent in 
order to support the weight of the vent, but shall 
not be allowed to deform or damage the vent. 
Anchors or supports supporting the weight of the 
vertical vent shall be in addition to the required 
pipe straps referred to in (a), (b) and (c) above 
which are intended only to maintain the position 
of the vertical vent while allowing for expansion 
and contraction. Make certain that allowance for 
expansion and contraction is provided in all venting 
installations.










