11
Combustible Floor Installations
Combustible Floor Installations
8” Metal Base
The Mason-Lite Metal Base ensures the minimum 8” (eight
inch) clearance above combustible flooring is maintained.
A layer of 1/2” minimum Concrete Board is required on
the top and mid section below as shown in
Figure 17
. The
required sizes are shown in the table below.
1/2” Thick Cement Board Dimensions
Model
A1
A2
B1
B2
MFPST-43
53”
28”
48”
23”
Figure 17 MFPST43 Metal Base Assembly
26 ga. galv.
Hearth Ember
Shields
Anchor Bracket All-Thread Rods are secured to the
bottom flange
of the Metal Base with eight (8) flat washers and eight (8) Nuts.
Place fiber blanket
underneath base
Four (4) All-Thread Rods
are secured to the
top
flange
of the Metal Base
with eight (8) flat washers
and eight (8) Nuts.
53”
28”
▲
!
IMPORTANT:
Remember to tighten up nuts below the floor after fireplace
installation in order to take up any slack in the threads.
Hearth Ember Shield:
Metal safety stripping is required between the front of the
Fireplace Hearth and Hearth Extension (not supplied). A 26
gauge galvanized 4” wide metal strip can be used. The length
needs to extend 2 inches beyond each side of the fireplace
opening. If two strips are used, make sure they overlap at
least two inches in the middle. The strip is placed about 2” into
the underside of the platform at the front of both openings on
the fireplace.
Note: When using an on-site-constructed hearth extension,
you may use a sand-cement grout between the hearth and
extension instead.
What You Will Need
What You Will Need
You will find that the MASON-LITE Fireplace is designed
to be completely assembled on-site, consisting of interlocking
precast parts. You will need a thin-set type mortar for bonding.
The parts of the fireplace are made of Mason-Lite’s incredibly
strong blend of specialty cement and a light weight aggregate.
IMPORTANT! When applying mortar, it is imperative that the
concrete blocks be maintained moist (not soaking) so they
don’t absorb the water out of the mortar and cause adhesion
to fail. Frequently run a damp sponge to the parts before
mortar is applied!
The installation of an anchor plate/damper is required
but not supplied. You may purchase it from any chimney
manufacturer or MFI. Also, an optional combustion air inlet
MFP4-AK can be obtained from MFI.
Refractory Firebrick Liners also need to be installed. These
should be a minimum of 1-1/8” (one and one-eight inches)
thick. The liner will be applied within the walls and hearth area
of the firebox.
Materials needed for concrete slab
(non- combustible) installation
•
Eight (8) pieces 3/8” rebar x 36” long (included with unit)
•
Eight (8) pieces of rebar x 12” long (included with unit)
•
Epoxy for securing rebar in footing / foundation
•
Three (3) - 90 lb. bags of ready mix concrete with 1/4” or
smaller aggregate
•
Mason-Lite Mortar (one 50 lb. bag)
Materials needed for combustible
wood floor installation:
•
Eight (8) pieces 3/8” rebar x 36” long (included with unit)
•
Eight (8) 12” long, 1/2-13 UNC All-Thread with (24) nuts
and washers
•
8 inch Metal Base.
•
1” ceramic fiber blanket the size of the hearth base to go
under the metal base.
•
½” cement boards.
•
Four or more fasteners to attach metal base to floor joists
•
Mason-Lite Mortar (at least one 50 lb. bag)
•
Three (3) - 90 lb. bags of ready mix concrete with 1/4” or
smaller aggregate.
Tools needed for both above installations:
• One 4’ level
• Roto-hammer with ½” drill bit
(needed for concrete slab
install only)
• Drill motor with mixer blade (to mix Mason-Lite Mortar)
• Two empty 5 gallon buckets (to mix Mason-Lite Mortar)
• One wheelbarrow
and shovel to mix concrete.
• Grout bag
• Triangular masonry trowel
• Rubber hammer
• Sponge and water bucket to wipe down and moisten parts
prior to applying mortar.
