How C.I.S. Works ~ Offsets
Illustration # 4 reveals how the C.I.S. spacers properly center a metal chimney liner even through offsets. By placing the C.I.S. spacers at closer intervals, the metal liner maintains the 1” separation between the liner and the inside surfaces of the chimney as it transitions through the offset. Without the spacers, the metal chimney liner would contact the interior walls above the offset, through the offset, and below the offset.

 
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