07/03
35035 Rev D
19
STS-42 INSTALLATION INSTRUCTIONS
Figure 23 - Position the Hearth Extension
15. 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.
Seal the crack between the hearth extension and
fireplace with a bead of noncombustible sealant.
See Figure 23. Apply a noncombustible finishing
material of your choice to the hearth extension.
16. Finishing Material
Do not install combustible materials over the face
of the fireplace! This poses a safety hazard and
may start a fire.
You may only use noncombustible
material over the face of the fireplace.
a. Combustible Material
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.
b. Noncombustible Material
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.
c. Noncombustible Sealant Material
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 metal fireplace front.
17. Mantel
A combustible mantel may be positioned no lower than
12 above the top of the fireplace opening. See Figure
6, page 9. 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
metal surfaces of the fireplace. This mantel clearance
is in accordance with
Section 7-3.3.3 of ANSI/
NFPA211
.
18. Glass Doors
This fireplace has been tested and listed for use with
doors as specified in Section C, Fireplace System
Components. Please refer to the manual packed with
each set of doors for installation instructions.
19. Chase Top
Construct a chase of desired materials maintaining a
minimum 2 air space around the chimney.
