7
that the minimum distances shown in Table 2 and
Figure 2 are met.
O. Install the hearth and or hearth extension. En-
sure the Table 2 and Figure 3 clearances and dis-
tances are maintained. Ensure that the hearth and
flooring under and in front of the hearth are made
of fully non-combustible materials, not just a non-
combustible floor covering. When the hearth in-
stallation is complete, you are now ready to install
the exterior.
3.3 Exterior finishing
The exterior finish of an indoor fireplace will vary as
compared to an outdoor application and may be lim-
ited depending on location in the home and framing
that encompasses the fireplace. Mantle and exterior
veneers may be fabricated stone, thin veneer or full
bed depth natural stone, tile, brick or stucco.
If the exterior finish is going to be stucco, stain, tile
or manufactured thin stone wrap outside of firebox
with metal lathe. Attach metal lathe to firebox using
concrete nails, tapcons, masonry or concrete anchors.
Natural stone, full bed depth or thin veneer, full size
brick, concrete pavers, CMU block, etc. do not re-
quire metal lathe.
Ensure same refractory mortar is used.
4.0 Installation of Chimney
Either one of two types of chimney may be installed,
the Stone Age masonry chimney system consisting,
of proprietary outer blocks and clay flues, or metal
pipe chimney pipe tested and certified to UL 103
standards for the US and ULC S604 standards for
Canada.
4.1 Stone Age Masonry System
The Stone Age Masonry chimney system consists of
stacking Stone Age chimney blocks and installing a
clay flue inside.
A. Place a clay flue inside the chimney block. The
holes in each corner of the chimney block allow the
placement of rebar and mortar for additional rein-
forcement, if desired.
B. Continue with stacking the outer blocks and
clay flues until the desired height is reached. Mor-
tar the flue sections together, and mortar the chim-
ney block sections together. There will be dead air
space between the flue and chimney block sections.
See Figure 20.
C. The chimney is completed by stacking as many
flue sections as necessary to reach chimney height.
Chimney plumbing can either be straight through
the ceiling and through the roof, or if the fireplace
is installed on an outside wall, the chimney can be
external to the house. When needed offset blocks
can be used for the chimney and should be engi-
neered to structurally support the offset with CMU
or custom fabricated steel post and or angle iron
capable of supporting the weight and height of the
chimney. Never exceed more than a 30 degree an-
gle when offsetting a chimney. See Figure 21.
D. Masonry chimneys taller than 24 feet should be
tied into the surrounding structure for additional
Offset
Blocks
CMU
Figure 21. Offset Blocks and CMU Support
Figure 20. Masonry Chimney Assembly
Summary of Contents for NA48
Page 13: ...13...
