Osburn 1100 MODEL INSERT Owner's Manual page 10

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 27" (686 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 27" (686 mm) above the top of the insert. If the depth of the shelf is not listed in
the table, add 21" (533 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 30" (762 mm) above the top of the insert
(21" (533 mm) + 9" (229 mm)).
SHELF POSITIONING
MAXIMUM SHELF
DIMENSION (X)
6" / 152 mm
8" / 203 mm
10" / 254 mm
12" / 305mm
SHELF POSITION
(I)
27" / 686 mm
29" / 737 mm
31" / 787 mm
33" / 838 mm
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