Mendota D30 Installation And Operating Instructions Manual page 24

Marble, Granite and Natural Stones
Marble, granite and other natural stone products are approved for use as mantel, facing and hearth pad materials with the
following limitations and understanding of these cautionary statements:
Never use a one-piece marble, granite or natural stone that is water jet or mechanically cut in a U -shape
as facing material to cover the sides and top areas around this product. Doing so can lead to crack
formation at the inner corners of the U shape due to thermal expansion.
Most marble slabs and marble tiles contain a polyester resin coating while most granite slabs and granite tiles contain epoxy
resin coatings. The polyester resin coatings and the epoxy resin coatings provide structural strength to the stone slabs and
prevent cracking, chipping and breakage during shipping and handling. These coatings also provide a glossy or satin surface
finish and help seal the stone surface.
The polyester resin used on marble slabs can discolor when exposed to temperatures greater than 150
and will structurally fail at temperatures above 230
resistant to discoloring and structural failures up to 3 50
discoloring, flaking or cracking of marble or granite.
Temperatures on facings around Mendota Gas Fireplace inserts
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can reach 350 F directly outside the top convection air gap and
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as high as 210 F at the maximum allowed mantel protrusion
level above the top convection air gap. These temperatures can
discolor polyester resin coated marble facings and can cause the
polyester resin coating to fail near the top convection air gap.
Mendota Fireplace insert cannot guarantee suitability
of use of any marble slabs or tiles that have a
polyester resin coating applied to it and cannot
guarantee against discoloration or structural failure of
marble or polished stone facings that have a polyester
resin coating. Consult with your local stone supplier.
Prior to use of any marble, granite or polished stone facing
material, especially white colored ones, run heat exposure tests on a sample piece. Expose sample pieces to temperatures
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between 275 F and 350 F for a period of eight hours. Compare the heat exposed sample to a control unheated piece and judge
for color changes. Do not use if any color changes are evident.
Mendota recommends the use of honed bare marble and bare stone facing materials or honed bare granite
and epoxy resin coated granite only.
Mendota cautions that due to natural structural defects that can exist within marble and stone pieces, cracking and/or flaking
of the marble or stone is possible and must be considered prior to selection and application around Mendota Fireplace inserts.
Mendota further cautions that proper adhesives be used to attach stone facings. Pay attention to the potential of off-gassing of
chemical vapors from mastic and other adhesives. Improper selection can lead to emission of chemicals with unwanted smells.
85-03-01071
Figure 3-18 Three Piece Stone
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F. The epoxy resin coating used on granite slabs are
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F.Mendota does not assu me any liability for
D30 DEEP TIMBER
Figure 3-19 Top Air Gap
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