Specifications

CW2500 Insert Installation and Operation Manual
30
Non-combustible floor protection of at least 3" (76 mm) in depth must be installed in front
of the fireplace hearth extension.
If the extension of the masonry hearth is raised at least 8" (F) from the floor protection, a
non-combustible material without an R factor extending 16 " (406 mm) (USA)/18’’ (457
mm) (CAN) from the front of the insert is required.
If non-combustible material floor protection needs to be added in front of and level with the
hearth extension of the masonry fireplace, an R factor equal to or greater than 2 is
required.
The use of an R value is convenient when more than one material is going to be used in
the hearth extension to cover the combustible surface. This is because R values are
additive, whereas K values are not.