MAGNUM MASONRY MANUAL – MAY 1999 PAGE - 7 -
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Excavate a hole to conform to the frost level (approximately 48” deep in the northern climates).
Allow the footing to be in excess of 6” beyond the area needed to install the unit.
NOTE:
If the unit is
being installed on an existing slab, you need 12” of slab thickness to support the masonry chimney.
•
Set up forms and pour the foundation concrete. (A) The foundation must be a minimum of 12 Inches
thick.
NOTE:
Refer to figure ____ for placement of re-bar. Rebar must be used. If large amounts of
brick or stone are to be used or if masonry chimney 19’ or taller is to be used pour the slab of 18”
thick. The fireplace foundation can be located either on an outside wall or on the inside of the
structure.
•
Allow 24 hours minimum to set up before continuing.
•
Lay up 8” x 8” x 16” concrete block from foundation up to ground level. Reduce foundation block
dimensions to accommodate 4” of insulation and 4” of face brick (allow more for stone). Continue
laying block bringing up this same dimension to floor level.
NOTE:
See Figure ____. Decide at this
point whether an ash pit is to be used.
•
If the foundation hole is to be used as an ash pit, install an airtight clean-out door above ground level.
(See Figure ____).
•
Form up and pour 6” concrete slab. Refer to Re-bar requirements (Figure __). A thermo-break of
insulation must surround this slab if installed on an outside wall (see Figure __).
NOTE:
If an ash
dump is to be used, leave a 5” x 10” hole in the slab.
•
Construct the inner chamber wall using 4” x 8” x 16” lightweight Hadite block.
Note:
If installing
adjacent to combustible materials, leave at least 6” of open air space between the inner chamber’s
outside block wall and combustible surface. Cover entire area with fiberglass batts. Do no use
Styrofoam. The two sidewalls of the chamber must be started 4” back from the faceplate to allow for
proper placement of face brick. Allow for a fiberglass insulation buffer between face brick and any
contact with metal.
Note:
Use metal ties to insure a proper seal when joining the face brick wall to
the inner chamber wall.
•
Continue to lay up block until reaching the desired height of the combustion air intake. At this point,
run the 6” intake pipe through the chamber wall and secure with mortar. Leave enough pipe to
accommodate a positive connection from the unit to the outside. The duct must terminate below the
level where it enters the firebox to minimize a reversed flow condition.
INSTALLATION
ELECTRICIAN’S NOTE:
If a fan is to be used, install electrical conduit in the slab allowing
for a serviceable limit switch or thermo-disc to be used. A rheostat to control the blower
speed should be mounted conveniently nearby. Building codes require at least 16” non-
combustible hearth extension across the front of the fireplace opening (See your local listing
for more information).
