Osburn OB01801 - Manual (Page 9)

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2.4 The masonry fireplace's draft control system
If the fireplace's draft control system is to remain in the masonry fireplace, it must be locked open for
access of the chimney liner or removed entirely. If you remove draft control system from the masonry
hearth, you will need to install the metal plate (27009), supplied with the owner’s manual kit, indicating
that the masonry hearth has been modified. It must be secured inside the masonry hearth, in a visible place
and easy to locate.
2.5 Compliance of a combustible top shelf
To ensure compliance of an existing top shelf or to install any combustible shelf, refer to table below
and Figure 2.5 for a safe installation or to perform changes if necessary. For example, a shelf with a 6’’
depth (152 mm) must be installed at least 22" (559 mm) above the top of the insert (see Figure 2.5).
Different shelf dimensions are listed in the following table in order to facilitate installation. However, no
combustible shelf can be installed at less than 22" (559 mm) above the top of the insert. If the depth of
the shelf is not listed in the table, add 16" (406 mm) to the depth of your shelf to obtain the safe
positioning of your shelf. For example, for a 9" (229 mm) shelf, the safe positioning would be 25" (635
mm) above the top of the insert (16" (406 mm) + 9" (229 mm)).
SHELF POSITIONING
MAXIMUM SHELF
DIMENSION (X)
SHELF POSITION
(I)
6" / 152 mm 22" / 648 mm
8" / 203 mm 24" / 698 mm
10" / 254 mm 26" / 749 mm
12" / 305mm 28" / 800 mm