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139684_Rev_7 / C 450 Kennebec 7 / 17
Hearth Protection Requirements
The floor area in front of fireplace insert must be
protected from live sparks and radiant heat.
• Materials: Hearth protection must be noncom-
bustible insulating board, having an R value of
2.92 (0.343 K-value) such as Kaowool® 2600 #15
or the equivalent mortared masonry material.
See Appendix A on page 19 for information how
to calculate the R-value of alternative materials.
Alternate protection must composed of materials
as specified by NFPA 211.
• Protected Area: 18” Deep x 40” Wide
A) Front - The protection must extend at least 18
inches (457 mm) forward from the door opening.
B) Sides - Protection must extend 20 inches
(508 mm) to both sides of the centerline of the
insert.
• Note that the firebox may extend out forward of
the fireplace face depending on where the cabinet
sleeve has been set to accommodate flue connec-
tion. Always measure hearth protection from the
final, installed position of the firebox and the door
opening. See figures 6 and 7.
Firebox
Sleeve
Figure 7. Provide hearth protection to accommodate
maximum firebox extension forward of fireplace face.
6 1/2”
(165 mm)
Figure 6. Sleeve adjustment results in minimum firebox
extension forward of fireplace face.
Firebox
Sleeve
Flush Firebox
Extended Firebox
