12
1) Place the Mason-Lite Fireplace hearth base on top of your
non-combustible floor or metal base. For concrete slabs,
supporting floor needs to be rated at ASTM 90.
2) a)
Combustible Floor Installations:
Mix up a batch of mortar and place hearth slabs on
top of cement board which sits on top of the Raised
Metal Platform (see Figure 18). All-thread rods should
stick up through the holes on the hearth slabs.
HEARTH PIECE
ALL-THREAD 12”
WASHER/NUT
CONCRETE BOARD
(NOT PROVIDED)
METAL
BASE
INSULATION
BLANKET
WASHER/NUT
WASHER/NUT
ALL-THREAD 6”
PLYWOOD SHEATHING
EMBER SHIELD
(UNDER FP OPENING)
FLOOR JOIST
BRACKET
Figure 18
b)
Non-combustible Floor Installations:
Draw an outline of the hearth area based on the
dimensions shown in Figure 19. Position Hearth slabs
and mark rebar center locations.
Figure 19
Four 26ga.galv. 4” wide
Hearth Ember Shields
required (not supplied)
LH Hearth 2nd
RH Hearth 1st
53”
28”
Apply mortar
between joints
2” min
overlap typ.
Drill 4 inches into concrete slab and secure the four
pieces of rebar with epoxy (Figure 20).
Drill Ø5/8” hole
x 4” deep
Epoxy #3 rebar
centered into hole.
Use ITW Epoxy or
Simpson Epoxy.
For concrete
foundations
less than 6”
thick, drill
slanted.
Figure 20
3)
Before installing the side walls, confirm placement of
outside combustion air side block (if required), this can
be installed either side depending on which side is
accessible to outside combustion air. Prepare side wall
footprint with the prepared mortar.
4)
Keep the assembly of the next sections of the firebox
side walls moving up, keeping components moist, mixing
mortar as you need it and properly threading mortar as
you stack each section, one onto the next. Constantly
check for squareness and levelness while building each
MFPST43 Fireplace Assembly
MFPST43 Fireplace Assembly
Field Assembly Procedures
Field Assembly Procedures
a) Mixing the MASON-LITE mortar – The mortar comes
premixed and should be dry. Be sure to use clean water and
work it up into a mixture that is pasty but not lumpy. If it’s
too thin and the surfaces don’t stay moist, the components
will not adhere. Load the mixture into a standard grout bag.
b) Apply about ½” (one-half inch) thread of mortar. The mortar
bead should be approximately ½” (one-half inch) away from
all edges. The mortar has a considerable amount of holding
power so do not overload the components with too much
mortar. Keep the components moist at all times!
c) Some mortar will “ooze out” when placing components
together, this is normal. Wipe excess away with a trowel. Do
not cover component surfaces completely with mortar. Do
not apply the mortar in thick bands even if the component
you are working with is larger than the rest. You will want to
apply “stripes” of mortar in these situations.
d) Make sure components are level. It’s extremely important
that you pay careful attention to how you are assembling
the Mason-Lite Fireplace since every component builds on
the next. If you have to make any kind of an adjustment,
do not try to do it “by loading an opening” with mortar, this
will only result in a fireplace that will not be plumb or level.
Use wood shims instead.
You will find these small wood
shims supplied with the Mason-Lite Fireplace
and
you can nudge them in between openings to achieve the
precision you need in making component adjustments.
Once you have inserted any shims, you will want to
cover any gaps that may have resulted with the mortar.
