Heatilator NA36 Installation & Operating Instructions Manual page 21

NA SERIES INSTALLATION INSTRUCTIONS
19. Position the Hearth Extension
Position and secure the hearth extension over the
protective metal strips that have been placed partially
under the fireplace front. These strips should be
protruding approximately 2” from under the fireplace
front and 2” on both sides of the fireplace opening.
See Figure 19. Apply a noncombustible finishing
material of your choice to the hearth extension.
07/03
20. Finishing Material
You may only use noncombustible
material over the black face of the fireplace.
Material which is made of or surfaced with wood,
compressed paper, plant fibers, plastics, or any
material capable of igniting and burning, whether
flame proofed or not, plastered or unplastered.
Material which will not ignite and burn. Such
materials are those consisting entirely of steel,
iron, brick, tile, concrete, slate, glass or plasters,
or any combination thereof.
Sealants which will not ignite and burn; General
Electric RTV103 Black (or equivalent), Rutland,
Inc. Fireplace Mortar #63 (or equivalent).
After completing the framing and applying the
facing material (dry wall) over the framing, a ½”
wide (maximum) bead of noncombustible sealant
must be used to close off any gaps at the top and
sides between the fireplace and facing to prevent
cold air leaks.
Only noncombustible materials may be used to
cover the black metal fireplace front.
21. Mantel
A combustible mantel may be positioned no lower than
12” above the top of the fireplace opening. The
combustible mantel may have a maximum depth of
12”. Combustible trim pieces that project no more than
1½” from the face of the fireplace can be placed no
closer than 6” from the top of the fireplace opening.
Combustible trim must not cover the black metal
surfaces of the fireplace. This mantel clearance is in
accordance with
22. Glass Doors
This fireplace has been tested and listed for use with
doors as specified in Section C, “System Components”.
Please refer to the manual packed with each set of
doors for installation instructions.
17789 Rev H
.
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