9
The framing vary with each application and with the
front trim installed. Refer to the installation instructions
of the front trim chosen for more information.
Planning Wall Finish
Non-Combustible Materials Specifications
Non-combustible materials 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.
Materials that are reported as passing ASTM E 136,
Standard Test Method for Behavior of Materials in a
Vertical Tube Furnace at 750 °C shall be considered
non-combustible materials.
Combustible Materials Specifications
Materials made of or surfaced with wood, compressed
paper, plant
fi
bers, plastics, or other material that can
ignite and burn, whether
fl
ame proofed or not, or
plastered or unplastered shall be considered
combustible materials.
Non-combustible cement board—ZC applications
With most front trims, the 530
fi
replace installed in
a zero clearance application will require a ½” [13 mm]
thick non-combustible cement board or equivalent,
to be used as a wall surface immediately above the
unit—see front trim installation manual for more
information.
Extending the cement board well beyond the minimum
shown will help avoid cracking due to di
ff
erential
expansion of materials. Pre-drill cement board with
oversized holes and do not over-tighten screws to avoid
cracking due to heat expansion.
Standard gypsum wall board may be used beyond the
perimeter of the cement board although it is preferable
not to change materials to help avoid cracking.
Finishing around trims
Additional non-combustible material such as tile and
others may be applied over top of the wall surface or
you may choose to leave it
fi
nished clean with no tile.
Be aware that a trim is always required and that the
wall
fi
nish thickness must be taken into account for
all installations.
Avoiding Cracking Wall Finishes
If a clean
fi
nish with no tile, etc. is desired, joints in the
non-combustible board and the transition to gypsum
board will require special attention if future cracking is
to be controlled.
Shrinkage and di
ff
erential movement of the framing
and non-combustible wall board can transmit cracking
through to tiles, etc.
Be aware that temperatures on the non-combustible
wall surface above the appliance can exceed 185°F.
Below are some tips on how to best avoid any cracking:
• Allow materials to dry thoroughly before
fi
nishing the
wall. Cement board has the ability to absorb up to 30
percent of its weight in water and may shrink as much
as 1/8” over a 48” length when drying from a saturated
condition. Running the
fi
replace for an extended period
before
fi
nal
fi
nishing will help drive out moisture.
• Always pre-drill screw holes through cement board
and use screws with self-milling head.
• Always use mesh tape over joints.
• Always stagger joints in wall board.
• Behind joints, double up studs or use studs “on the
fl
at” to add extra support to the joint. Adhesive on
the backside of wall board behind any joints can help
control di
ff
erential movement.
• Use multiple, thinner coats of joint compound and al-
low to dry thoroughly between coats.
• Ensure framing materials are dry.
• After
fi
nishing the wall, introduce heat gradually to slow-
ly dry any excess moisture rather than drying too fast.
• Avoid notching cement board or tiles around corners
of window opening and instead provide a joint that
intersects the corner.
• Avoid using large, one-piece slab of material with a
cut-out in the middle as a surround for the
fi
replace.
Expansion above the opening will cause cracking at in-
side corners. Provide a joint that intersects the inside
corner to avoid cracking.
Framing
Cracks
Provide joints either here or here
Wall Finish
