Heat & Glo XLR-PB-CE Owner's Manual page 46

FIREPLACE OPENING
43 cm TO 44 cm
Figure 13.4 Required Fireplace Opening Height
Note: The lower cover panel must be pushed all the way
down. The outer finishing flanges should line up. The
fireplace opening must be between 43 cm and 44 cm for
the decorative fronts to fit correctly. See Figure 13.4.
Finish and Sealing Joints
All joints between the finished wall sheating and
the appliance must be sealed with non-combustible
materials. Sealants, such as caulk or mastic used to
seal the gap between the wall and the fireplace, should
be rated at a minimum continuous exposure to 300°
F. Wall board joints can be taped and sealed with
combustible drywall tape.
Finishing Around Opening with Gypsum Wallboard
Gypsum wallboard (drywall) joints adjacent to the
fireplace opening require special attention to minimize
potential development of cracking. Hearth and Home
Technologies recommends the following steps to
minimize potential cracks in the finished drywall around
the fireplace opening:
• When installing gypsum wallboard around the fireplace,
install the hole for the fireplace opening in a single
wallboard sheet, if possible. This will minimize the joints
adjacent to the fireplace opening.
• The factory-supplied non-combustible board and the
gypsum wallboard must join on the structural framing,
where applicable. Wallboard and non-combustible
board should be fastened to the framing with at least
3,2 cm long screw fasteners, located within 3,8 from
each corner, and at no more than 30,5 intervals along
the joint length.
• The wall-board joints should be finished with a Taping
Coat, followed by at least two subsequent Finish Coats
of joint compound.
46 Heat & Glo • XLR-N-CE, XLR-PB-CE • 2198-900 Rev. J • 5/12
• For the initial Taping Coat, it is critical that a general-
purpose chemically hardening joint compound, such as
SHEETROCK™ Brand Durabond™ Setting-Type Joint
Compound, be used to fill the joint and embed the mesh
tape. Fiberglass-mesh tape is recommended because it
will provide a more crack-resistant joint than one finished
with paper tape. Let the Taping Coat properly cure before
applying subsequent Finish Coats.
• For the second and third finishing coats, it is acceptable
to use a light-weight joint compound and standard
application, curing and sanding methods.
• Do not operate the fireplace during the drywall finishing
process. Allow the finish coat to cure for at least 24
hours prior to using the appliance.
Painting
If desired finishing includes a painted wall, 100% acrylic
latex with compatible primer is recommend around the
appliance. Oil-based or standard acrylic paints may
discolor due to heat exposure.
Wallboard Joint-Crack Prevention and Repair
Wallboard joints around the fireplace will be affected by
exposure to elevated temperatures, along with other en-
vironmental and structural factors. The specific methods
presented in the previous section will help prevent or
minimize development of cracks.
If a crack does emerge adjacent the fireplace, it can be
permanently repaired by filling it with spackling paste or
paintable latex caulk, followed by repainting.