15
Fireplace Finishes & Combustible Trim
Clearances
Hearth Material & Dimensions – Codes are strict regarding the
use of proper materials for hearth extensions and the proper
dimensional characteristics.
All hearth extensions must be made of code-rated,
noncombustible materials such as tile, brick, concrete or
stone. MASON-LITE Fireplaces usually have an opening of
approximately 8 sq. ft. (eight square feet) that translates to a
hearth extension of about 20” (twenty inches) at the fireplace’s
opening and about 12” (twelve inches) extension at each side.
These relative dimensions are also covered by code.
Mantle and Mantle Shelf Clearances
As with any radiant heat fireplace, all MASON-LITE Fireplaces
must comply with building code safety clearances, for units
that have openings of 6 sq. ft. (six square feet) or greater.
For Mantel clearances see
Figure 6
.
Walls that Adjoin – your fireplace cannot be installed closer
than 2 ft. (two feet) to any adjoining walls in the room where
the fireplace is.
Caution in Regards to Combustibles – If any part of the
fireplace or objects in the room (curtains, rugs, paint, cushions,
etc.) start to show warping or discoloration due to heat from
the fireplace, it is time to take immediate action. Do not use
the fireplace until you have figured out how to address the
problem. You are facing a potential fire hazard. MFI cannot be
responsible for the make-up of material on the exterior of the
fireplace you have chosen, nor can MFI be held responsible
for the materials in a room that may be responding negatively
to heat. However, in almost all cases, there is a solution to
the problem, either by making adjustments to airflow or the
modifications to the room itself.
Installing Outside Combustion (make-up) Air
1) The Mason-Lite Fireplace needs enough make-up air
to function properly and some local building codes may
require outside combustion air to be provided. If no make-
up air is provided, improper flue drafting may occur,
creating negative pressure whereby smoke may enter the
home, especially in homes that are very well insulated
and tightly sealed. Check local building codes for specific
requirements.
2) Install Combustion Air Kit MFPST-AK into the Mason-Lite
Firebox through the side wall opening provided. The tubing
that goes out of the firebox wall must feed into a flexible
metal conduit as the source for outside combustible
air. It can go straight out through an outside wall or into
a ventilated crawl space. If crawl space is used, check
codes for proper termination.
3) Be sure that you carefully check the source of the outside
air before you choose the site for your air intake. You don’t
want a place where snow will collect, where it could easily
flood, where bushes or trees will be growing or a location
that is too close to any other structure.
4) Install a screened termination cap to keep out animals.
Figure 27
