The assembled wood fireplace is packaged
with:
1 - One envelope containing the literature pack-
age which consists of the homeowner's
manual, installation instructions, warranty
and combustion air cover (located in the
firebox).
2 - One Combustion Air Kit (90L83).
3 - Two Door Sets.
IMPORTANT: PLEASE READ AND
UNDERSTAND THESE RULES TO
FOLLOW FOR SAFETY.
SAFETY RULES:
WARNING
To avoid the risk of damaging
fireplace materials and increasing the risk of fire, do not use the
fireplace to cook or warm food.
2
1. Before starting your fireplace installation,
read these installation instructions carefully
to be sure you understand them completely
and in entirety. Failure to follow them could
cause a fireplace malfunction resulting in
serious injury and/or property damage.
2. Always check your local building codes.
The installation must comply with all local, regional, state and national codes and
regulations.
3. These fireplaces must be installed with
Security Chimneys FTF8 (8" inside diameter)
Chimney System only. These systems are
intended for use in any application where
a traditional masonry type fireplace would
apply. The chimney system must always
vent to the outside of the building.
4. To ensure a safe fireplace system and to
prevent the build-up of soot and creosote,
inspect and clean the fireplace and chimney
prior to use and periodically during the heating season.
5. Burn approved fuels only as defined in the
Homeowner's Care and Operation Manual.
6. DO NOT use charcoal or coal under any
circumstances.
7. NEVER use gasoline, gasoline-type lantern
fuel, kerosene, charcoal lighter fluid, or
similar liquids to start or “freshen up” a fire
in this fireplace. Keep any flammable liquids
a safe distance from the fireplace.
8. NEVER leave children unattended when there
is a fire burning in the fireplace.
9. Always keep flue damper open when heat is
present in the fireplace.
10. Before servicing, allow the fireplace to cool.
Always shut off any electricity or gas to the
fireplace while working on it. This will prevent
any possible electrical shock or burns.
11. This fireplace is not intended to heat an
entire home or be used as a primary heat
source. It is designed to ensure homeowner
comfort by providing supplemental heat to
the room.
12. Always ensure that an adequate supply
of replacement combustion air from the
outside of the house is accessible to the fire
to support normal combustion. Fireplaces
consume large volumes of air during the
normal combustion process.
• In the event the home is tightly sealed with
modern energy efficient features, the combustion air kit (provided) may not provide
all the air required to support combustion.
• The manufacturer is not responsible for any
smoking or related problems that may result
from the lack of adequate combustion air. It
is the responsibility of the builder/contractor
to ensure that adequate combustion air has
been provided for the fireplace.
13. Always ensure that the air inlet to the fireplace
is free from debris and any other obstructions
that can block the entrance of air.
14.DO NOT use a fireplace insert or any other
product not specified by the manufacturer of
this LHP appliance for use with this fireplace.
All gas log sets must be operated with the
damper clamped open.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
WARNING
This fireplace has not been tested
with an unvented gas log set. To
reduce risk of fire or injury, do not
install an unvented gas into
this fireplace.
15. "Smoke free” operation is not warranteed
nor are we responsible for inadequate system draft caused by mechanical systems,
general construction conditions, inadequate
chimney heights, adverse wind conditions
and/or unusual environmental factors or
conditions beyond our control.
16. Never, under any circumstances, install
a fireplace, chimney component or any
accessories, that has visible or suspected
physical damage as a result of handling
or transportation. These items should be
inspected by your distributor or qualified factory representative to ensure safe condition.
When in doubt, consult your distributor.
17. For additional safety considerations and
complete operating instructions, refer to
the Care and Operation Manual provided
with the fireplace.
TOOLS AND BUILDING SUPPLIES
NORMALLY REQUIRED
ToolsSupplies
Phillips screwdriver
Hammer
Saw and/or sabersaw
Level
Measuring tape
Plumb line
Electric drill and bits
Pliers
Square
PRECAUTIONS
The most important areas of concern dealing
with the installation of factory-built fireplaces
are clearances to combustible materials, proper
assembly of component parts, height of the
chimney system, the proper use of accessories
supplied by the manufacturer and the techniques
employed in using finishing materials applied to
the wall surrounding the fireplace, hearth extensions and wall shields. Each of these topics will
be covered in thorough detail throughout this
manual. Please give each your special attention
as you progress with your installation.
Note: These fireplace systems are not difficult
to install. However, in the interest of safety, it is
recommended that the installer be a qualified or
certified “tradesman” familiar with commonly
accepted fireplace installation and safety techniques as well as prevailing local codes.
The CST38MH Series is a radiant-heat, twosided fireplace with standard glass doors and
an outside combustion air kit is provided.
A steel grate is also included to properly position the fire and limit the amount of fuel. IF A
REPLACEMENT GRATE IS NEEDED REPLACE
THE GRATE WITH MODEL SGR-38B ONLY.
Note: Illustrations shown reflect “typical”
installations with nominal dimensions and
are for design and framing reference only.
Actual installations may vary due to individual
design preferences. However, always maintain
minimum clearances to combustible materials
and do not violate any specific installation
requirements.
These fireplaces have been tested and listed
by OMNI Test Labs (Report No. 116-F-20-4) to
U.L. standard 127. These units are intended for
installation in Manufactured Homes, residential
homes and other buildings of conventional
construction including commercial.
These fireplace systems are designed for installation in accordance with the National Fire
Protection Standard for chimneys, fireplaces
and solid fuel burning appliances; NFPA 211latest edition and in accordance with codes
such as the BOCA Basic/National Codes, the
Standard Mechanical Code and the Uniform
Building Codes.
TYPICAL INSTALLATION
Chimney and
Termination
Firestop
Thimble
WARNING
Failure to use manufacture
provided parts, variations in
techniques and construction
materials or practices other than
those described in this manual
may create a fire hazard and void
the limited warranty.
WARNING
Do not pack or fill required air
spaces with insulation or other
material. No material is allowed
in these areas. Secure the
airspace around the chimney
with the firestop/thimble before
completing the installation.
Maintain 2" clearance between
chimney and thimble.
WARNING
If insulation is used, the fireplace
must not be placed directly
against it. Insulation or vapor
barriers, if used, must first be
covered with gypsum board,
plywood, particle board or other
material to assure insulation
and vapor barriers remain in
place.
When complete these fireplace systems consists of four basic “sub-systems”:
1. The Fireplace
2. The Chimney and Termination
3. Glass Doors
4. Combustion Air Kit
CLEARANCES AND HEIGHT
REQUIREMENTS
The fireplace opening must be kept a minimum
of 8" (203 mm) from a protected combustible
side wall. A perpendicular side wall can not be
closer that 18" (457 mm). If there is a continuous perpendicular side wall closer than 18" from
the fireplace opening, it must be protected with
a 40" x 40" x 1/2" (1016 mm x 1016 mm x 13
mm) wall shield constructed of a durable noncombustible material with an equal or greater
insulating value than k=.84 BTU IN/FT2 HR °F
(refer to Pages 18, 19 and 20).
As with all chimney installations, avoid overhead
obstructions such as trees, power lines, etc.
Additionally chimney terminations must meet
certain clearance to roof requirements detailed in
the paragraph titled Ten-Foot Rule Summary.
The fireplace and chimney system must be
enclosed when installed in or passing through
a living area where combustibles or people may
come in contact with it. This is important to prevent possible personal injury or fire hazard.
For questions, please call your distributor or
the manufacturer. Special restrictions apply to
the front and facing of the fireplace and nearby
walls (See Pages 18, 19 and 20).
CHIMNEY SYSTEM
These fireplaces are designed and code listed
for use with Security Chimneys FTF8 chimney
System only. Always use Security Chimneys
FTF8 chimney components with these fireplaces.
Do not modify or alter these components as
this may cause a potential serious hazard and
void the Warranty.
*Construction Materials:
• Framing Materials • Paneling
• Particle Board • Flooring
• Dry Wall • Plywood
• Noncombustible Insulating Materials
• Etc.
Chimney Height
The total height of your Fireplace systems from
the surface the fireplace rests on to the chimney
top must not exceed 80' (24.4m) and must also
meet minimum system height chart.
Figure 1
Outside Combustion Air Kit
The fireplace may be placed on or near normal
construction materials*. The combustion air
kit, firestop spacer and roof flashing (not chase
flashings) may be placed directly on or against
normal construction materials.* The chimney
and fireplace outer wrapper require a minimum
2" and 1/2" air space to combustibles respectively.
A combustible mantel may be installed 12" above
the opening of the fireplace as per NFPA 211latest edition.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Minimum System Height
Security's FTF8 Pipe
Vertical Installation15' 0"
One Offsets16' 0"
Two Offsets25' 0"
Table 1
3
Wall
Covering
Black Portion Of Frame
Not To Be Covered With
Combustible Materials
Safe
Zone
30°
11-3/8”
18”
Door
Opening
1”
Insulate Joists
Same As Ceiling
Draft Stops
Firestop
CTDT
Termination
Note: NonCombustible
Chase
Flashing
Must Be
Used To
Cover
Chase
Opening
Optional
Insulation
In Outside
Walls Of
Chase
8'
Level
Ground Level
Damper
Closed
Damper
Open
Lintel
Solid
Fireplace
Continuous
Surface
Base
Insulation
(Thermal Barrier)
Base Requirements
Note: Local codes may not require firestopping
at the ceiling levels for outside chimney enclosure installations. However, it is recommended
for safety and the reduction of heat loss.
WARNING
Do not obstruct the collar openings around the base of the chimney at the top of the fireplace.
Do not insulate the chase cavity
with blown or fill type insulation
materials.
ASSEMBLY OUTLINE
Before You Start
Check your inventory list to be sure you have
all the necessary parts supplied in good usable condition. Check also for any concealed
damage.
Check the operation of the damper. The damper
is controlled through the use of a control lever
located within the firebox opening at the top
center just behind the firebox lintel (Figure 3).
The control lever snaps into place at the extreme
range of motion, up and back in the closed
position. When pulled forward and down, the
damper is open.
Figure 4
WARNING
This fireplace and chimney
system is not approved for use
in a bedroom or any room used
for sleeping.
Carefully consider the position of the fireplace
opening with respect to the location of adjacent
or nearby stairwells, bath or kitchen exhaust
fans and/or return air registers for forced air
furnaces/air conditioners that could cause a
smoking fireplace condition if the house is
tightly insulated.
4
Front Face
Model Shown
Figure 2
Chimney Enclosure
Construct a box-like framed structure to enclose
the fireplace and chimney within the confines
of the manufactured home, not necessarily
above the roof line.
As with all chimney installations, avoid overhead
obstructions such as trees, power lines, etc.
The chimney/fireplace enclosure should be
constructed and insulated just like any outside
wall. In a cold climate, we recommend the base
of the chimney/fireplace enclosure should also
be insulated between the solid continuous floor
beneath the fireplace and the chase bottom.
Insulation in a cold climate installation is not
required for safety.
When locating the fireplace, consideration must
be given to combustibles and final finishing. For
an example of this, see Figure 5 and confine
the final location of combustible finish materials
to the "Safe Zone".
DO NOT permanently place furniture or other
items such as decorative pillows within 60" of
the fireplace front face.
Figure 3
LOCATION OF FIREPLACE
Carefully select the proper location for heat
circulation, aesthetics, chimney obstructions
and clearance to side wall(s). With proper preplanning, a slight adjustment of a few inches
can save considerable time and expense later
during construction and assembly.
Figure 5 - Clearances
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
ASSEMBLY STEPS
Hearth
Extension
Floor
Hearth
Extension
Metal Safety
Strips
Floor
Hearth
Extension
Floor
Hearth
Extension
Metal Safety
Strips
Platform
Note: The following steps represent the normal
sequence of installation. Each installation is
unique, however, and might require a different
sequence.
1. Position firebox prior to framing or into
prepared framing.
2. Install the chimney system.
3. Install outside combustion air kit.
4. Plumb gas line if a decorative gas appliance
will be used. (Gas connections should only
be performed by an experienced, licensed/
certified tradesman).
5. Install both “All-GlassTM” door assemblies.
6. Complete finish wall material, surround and
hearth extension to your individual taste.
7. Inststall the glass doors provided.
Study the three dimensional illustration (Figure
1) to get a general idea of each element of your
fireplace system.
PRE-INSTALLATION NOTES
2. Measure the square footage of the floor space
to be occupied by the system, surrounds and
hearth extensions.
3. Note the floor construction, i.e. 2 x 6’s, 2 x
8’s or 2 x 10’s, single or double joists, type
and thickness of floor boards.
4. Use this information and consult your local
building code to determine if you need additional support.
CAUTION
Do not block the heat-circulating
air inlet and outlet ports. Doing
so may result in a potential fire
hazard.
CAUTION
The structural integrity of the
manufactured home floor, wall,
ceiling and roof must be maintained.
INSTALLING THE FIREPLACE
Step 1. Slide the fireplace into prepared framing
or position fireplace in its final position
and frame later.
The fireplace may not be recessed into a
combustible floor. Maintain the floor to hearth
clearance established by the fireplace lower
front face.
Step 2. Insert the provided metal safety strips,
beneath the fireplace as illustrated
(Figures 6 and 7). The safety strips
should overlap 1/2" for continual
coverage of the floor.
Note: Safety strips are not required when fireplace rests on a noncombustible surface.
The fireplace may be installed directly on a
combustible floor or raised on a platform of
an appropriate height. Do not place fireplace on
carpeting, vinyl or other soft floor coverings. It
may, however, be placed on flat wood, plywood,
particle board or other hard surfaces. Be sure
fireplace rests on a solid continuous floor or
platform with appropriate framing for support
and so that no cold air can enter the room from
under the fireplace.
The fireplace may be positioned and then the
framing built around it, or the framing may be
constructed and the fireplace positioned into
the opening.
Usually, no special floor support is needed for
the fireplace, however, to be certain:
1. Estimate the total weight of the fireplace
system including chimney and surround
materials such as brick, stone, etc., to be
installed. Shipping weights for the fireplace
may be found on Page 7.
The firestop thimble supplied with the unit must
be used on a manufactured home installation.
The firestop thimble must extend completely
though the roof cavity to the outermost plane
of the roof (See Figures 21, 22 and 23).
Maintain 1" clearance between the thimble and
the chimney.
If you plan to raise the fireplace and hearth
extension, build the platform assembly then
position fireplace and hearth extension on
top. Secure the platform to the floor to prevent
possible shifting.
CLEARANCES
Minimum clearance to combustibles for the
appliance is as follows: sides - 1/2" (12.5 mm),
floor - 0" (0 mm), adjacent wall - 18" (457 mm),
ceiling - 37-1/2" (953 mm).
Figure 6
Figure 7
Note: Install the hearth extension only as il-
lustrated.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
5
Metal
Safety Strips
2" Min.
(51 mm)
Platform
Metal
Safety Strips
*
2" Min.
(51 mm)
*
*
4 x 6 Header
Spacer
2 x 4 False
Header
No Combustible
Materials in
Shaded Areas
No
Combustible
Materials in
Shaded Areas
IMPORTANT
Under no circumstances can the
fireplace top spacers (Figure
13) be removed or modified,
nor may you notch the header to
fit around or be installed lower
than the spacers. The header
may be in direct contact with
the top spacers but may not be
supported by them.
Figure 8
Figure 9
The safety strips should extend in front and
sides of the fireplace opening 2" (51 mm) . In
the event a wooden support is used to elevate
the fireplace above the floor, a “Z” type safety
strip should be fabricated and used to protect
the front surface of the wood support as well
as the floor beneath the hearth extension (see Figures 8 and 9). The safety strips should be
tacked down to prevent possible movement.
Figure 10
If the appliance is to be elevated above floor
level, a solid continuous platform must be
constructed.
The header may rest on the top metal spacers,
but must not be notched to fit around them.
Consult all local codes.
Figure 11
Figure 12
6
Note: The “Z” type safety strip is not supplied.
Step 3. Refer to fireplace drawings and speci-
fications on Pages 7 and 8 for framing
dimensions and details. False header
may be positioned directly on top of
the fireplace spacers (see Figures 10, 11 and 12).
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
7" Min.
(178 mm)
23 ¹⁵⁄₁₆"
(608 mm)
42 ³⁄₄"
(1086 mm)
49"
(1245 mm)
40 ¹⁄₄"
(1022 mm)
4 x 4
Header
2 x 4
False Header
(Optional)
42 ³⁄₄"
(1086 mm)
49"
(1245 mm)
FIREPLACE SPECIFICATIONS
39-1/4"
(997 mm)
23-15/16"
(608 mm)
25-3/16"
(640 mm)
8"
(203 mm)
Front View
Top View
End View
12-1/2"
"
(318 mm)
48-3/4"
(1238 mm)
8-9/16"
8-13/16"
(217 mm)
3-7/8"
(98 mm)
42-1/2"
(1080 mm)
(224 mm)
Outside (combustion)
Air Inlet
12-1/2"
(318 mm)
48-3/4"
(1238 mm)
10-1/2"
(267 mm)
5-3/4"
(146 mm)
21"
(533 mm)
5-1/4"
(133 mm)
32"
(813 mm)
39-1/4" (997 mm)
38" (965 mm)
FOAK-6 Outside
Air Kit (provided)
Right Side of
Fireplace
Product Reference Information
Cat.
ModelShip.
No.
H4629 CST38MH237 lb.29.6 cu. ft.
Due to Lennox' ongoing commitment to quality,
all specifications, ratings and dimensions are
subject to change without notice.
All framing dimensions calculated for 1/2" dry wall
at the fireplace face. If sheathing the chase or
finishing with other thickness materials, calculations will need to be made.
See Page 8 for Ceiling and Roof Framing
Dimensions
Diagrams & Illustrations Not to Scale
OTL Report No. 116-F-20-4
Weight
Notes
Ship.
Volume
Outside (combustion) Air Kit
Required in Manufactured Home Installations
Figure 13
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
End View
Front View
7
FRAMING WALL VARIATIONS
A
B
Ceiling Framing
C
D
Roof Framing
Nailing
Flange
Framing
Stud
As many as six (6) different framed wall configurations can be constructed to enclose the
Fireplaces. The following illustrations depict
these variations of wall enclosures. Several of
these designs may incorporate book shelves,
wood storage boxes, etc.
CST38MH - Wall Types
Framing Dimensions for Ceiling
Framing Dimensions for Ceiling
Inches (millimeters)
Figure 17
Figure 14
“C” Type Wall
“T” Type Wall
“L” Type Wall
“H” Type Wall
“Y” Type Wall
Parallel Wall
Flue TypeAB
FTF8, Vertical
at 2" (51 mm)
FTF8 Offset 30°
At 2" (51 mm)
16 1/2"
(419 mm)
16 1/2"
(419 mm)
16 1/2"
(419 mm)
27"
(686 mm)
Figure 15
Framing Dimensions for Roof
Inches
FTF8 at 1" (USA)
Pitch
0/12
6/12
12/12
* Perpendicular to roof ridge
CD*
16 1/2"16 1/2"
16 1/2"
16 1/2"
19"
23 1/2"
Figure 16
Step 4. The fireplace should be secured to side
framing members using nailing tabs. Use 8d
nails (Figure 17).
Note: The nailing tabs are exempt from the
fireplace clearances described on the fireplace
clearance label.
INSTALL THE COMBUSTION AIR KIT
(required in Manufactured Home installations)
Outside air drawn into the fireplace supplies
air to the fire for combustion. The outside air
kit (FOAK-6, Cat. No. 90L83) must be installed
before the fireplace is framed and enclosed in
the finished walls.
Install the air intake Collar (provided) as shown
in Figure 18.
There is a one-hand operated shut-off valve
located in the enclosed corner of the fireplace
opening behind the screen. Refer to label for
directions of operation. The combustion air
damper should be fully open when the fireplace
is in operation and fully closed when the fireplace is not in use to prevent outside air from
entering your home.
Connect the 6” (152 mm) Class 0 or Class 1 air
duct to the outside air collar on the appliance
with the tie strip in the outside air kit (provided).
See Figure 18.
Route the Class 0 or Class 1 air duct out the
back or side wall, up through the ceiling or floor
joists to an outside wall. The air duct should be
located above snow level.
Outside combustion air may be run upwards
or vertically through framing and ceiling joists,
with the hood installed through an outside
wall and 3' (914 mm) below the termination.
Ducting may also be run downward through
floor joists and under the home to a ventilated
crawlspace not considered part of the living
area of the home.
8
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Cut or frame a hole through the outside wall for
Air Inlet Assembly
(Attach To Floor)
Non-Combustible
Class 0 Or Class 1
6 Inch Air Inlet Duct
Actuator
Arm
Clamp
Securely
At Top And
Bottom
Vented Crawl Space
the installation of the duct inlet hood. A 6 1/2”
(151 mm) diameter hole is sufficient. Feed the
loose end of the flexible air duct through the
hole cut for the inlet hood and attach to collar
on inlet hood using the tie strip provided. Insert
hood into opening. Secure in place with the
No. 8 x 1-1/2” screws provided or with nails
driven through holes in hood flange. Seal with
noncombustible waterproof silicon type caulking. If additional length of duct is necessary,
purchase locally available Class 0 or Class 1
ducting. The duct may extend up to 50' (15.2
m) in any direction.
Note: Do not terminate combustion air kit in
attic space under any circumstances.
CAUTION
CAUTION
In no event may the total duct for
bringing in outside air exceed
50' (15.2 m).
Step 2. Using standard construction framing
techniques, construct opening for chimney route up through the ceiling(s) and
roof or through an outside chase.
Framing must maintain adequate mini-
mum air space clearance at all times.
CAUTION
Allow minimum 2" (51 mm)
chimney air space to combustible framing members throughout vertical or offset chimney
installation. Also maintain air
space on top of the fireplace
as defined by the spacers and
standoffs.
Never locate the air inlet where
it could be blocked by shrubs,
leaves, snow drifts, etc. Never
locate the air inlet in garage or
any area where there is another
fuel burning appliance or products emitting combustible gases
such as paint, gasoline, etc.
In cold climates, it is recommended that the combustion air
duct be insulated.
Figure 18 - Outside Combustion Air Kit
INSTALLING THE CHIMNEY SYSTEM
Step 1. Check flue damper for proper operation.
To open, push handle up and release.
Damper will open automatically. To
close, pull handle down and release
damper will fall to the closed position.
Note: The damper may be operated from both
firebox openings.
A minimum 2" (51 mm) air space must be
reserved for all combustible materials extending for any continuous length surrounding the
chimney.
Reference Figures 15 and 16 on Page 8,
which specify minimum ceiling and roof dimensions.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
9
For new construction, to determine chimney
Plumb Line
Firestop Spacer
F8FS-2
Room Above
Firestop Thimble
FM8-AT2
Attic Above
2”
Clearance
Minimum
Note: Trim Thimble/
Extension To Desired Length
And Pitch At The Rood Line
14" Min.
Pitched Roof
Pitched Roof
Bow Roof
14" Min.
Outer Pipe Of
Chimney
Outer Pipe Of
Chimney
Outer Pipe Of
Chimney
14" Min.
Thimble
FM8-AT2
13"
Thimble
FM8-AT2
Thimble
FM8-AT2
Thimble
Extension
F8-TE26-2
Thimble Cathedral
Ceiling
14" Min.
Outer Pipe Of
Chimney
Use Adjustable Thimble
FM8-AT2 For All Ceiling
Piches, From Flat To
3/12 Pitch.
center line, use plumb line from roof or ceiling above fireplace to center of flue collar on
fireplace.
For remodeling, plumb to center of flue collar
from ceiling above, drive nail through ceiling
from below to mark position, then mark and
cut to passage from above ceiling (around nail)
(Figure 19). Then plumb from ceiling or roof
level directly above hole which has just been
completed.
Figure 19
Step 3. Position appropriate thimble/firestop
Note: If there is a room above ceiling level,
firestop spacer must be installed on the bottom
side of the ceiling. If an attic is above ceiling
level, firestop spacer must be installed on top
side of ceiling joist (Figure 20).
spacer combination at ceiling and nail
temporarily with two (2) 8d nails or
equivalent fasteners (see Figures 21, 22 and 23). Use thimble/firestop spacer,
model FM8-AT2, if chimney penetrates
ceiling vertically. If chimney penetrates
ceiling at 30˚ angle (offset) chimney use
Model F8FS30-2. Use one fastener on
opposite sides to hold thimble/firestop
spacer combination in position. Nail
permanently, using at least two (2) more
fasteners, after chimney sections have
been assembled through the thimble/
firestop spacer combination and after any
necessary adjustments have been made.
Firestop spacer must be secured by at
least four (4) fasteners when completely
installed.
Figure 21
Ensure the thimble penetrates the roof opening.
The thimble must extend completely through the
ceiling or roof cavity to the outermost plane of
the roof. Note: Thimble extensions (F8-TE26-2)
are available from your dealer for constructions
in which the distance between the outside of the
roof and the inside of the ceiling exceeds 13".
The thimbles and their extensions provide for
zero clearances to combustibles and must be
used at the ceiling/roof in manufactured homes
(Figures 22 and 23).
Figure 22
WARNING
Do not allow insulating materials to
be blown into the space inside the
thimble and the chimney. To do so
could result in a fire hazard.
Figure 23
Step 4. Note: Chimney sections are con-
structed with a unique locking tab
design, which ensures an immediate,
tight assembly between sections. Plan
your chimney requirements carefully
before assembly as chimney is difficult
to disassemble after installation. If
disassembled, the tabs might become
damaged. Be certain tabs are properly
formed to ensure locking tabs engage
properly.
The Security Chimneys FTF8 chimney system
is a two piece chimney, which snap together
from the fireplace up. Start with the inner flue
section with the lanced end up, snap lock it in
to the matching collar on top of the fireplace.
At all subsequent joints, the upper flue section
fits into the preceding flue section. Each piece
snaps together by means of locking tabs (9
locking tabs per joint). Check each piece by
pulling up slightly from the top to ensure proper
engagement before installing the next section.
If the flue has been installed correctly, it will not
separate when you test it. Also, the inner flue
joint where each section is joined should be
tight and flat without gaps (Figure 24).
Figure 24
Outer pipe section installs in just the opposite
way; the lanced end goes down and each new
section goes OVER the outside of the previous
section installed (Figure 25).
10
Figure 20
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Locking Tabs
(Lances)
FTF8-S4 Stabilizer
2" (51mm) Min. Air Space
to Combustibles
FTF8 Chimney
FTF8 Flashing
Do Not Seal
Figure 25
Note: Assemble one component of chimney at
a time (inner section first, then outer section
last) before proceeding with the next complete
section.
Step 5. The height of vertical chimney pipe sup-
ported only by the fireplace must not
exceed 30'. Chimney heights above 30'
must be supported by a Model FTF8-S4
stabilizer installed at 30' intervals.
Note: The Model FTF8-S4 adds 3" net effective
height to the total chimney system.
Install the Model FTF8-S4 stabilizer by fitting
inner section down into respective section of
proceeding flue pipe and locking outer stabilizer
section into place over the outer chimney pipe.
Position for proper clearance through framed
opening and nail straps securely (under tension
in “shear”) into place on framing. Use 8d nails.
Attach successive lengths of chimney pipe
directly to stabilizer using same techniques as
described in Step 4 (Figure 27).
Next, slide roof flashing over extended chimney
section that previously has been installed above
the roof opening in Step 4. Slide flashing all the
way down until the flashing base rests flat on
the roof (Figure 28). Again, check the vertical
position of the chimney and the minimum air
space to combustibles.
Continue to assemble the chimney up through
framed ceiling opening. Assemble just enough
to penetrate the roof flashing openings (Figure
26). Always maintain 2" (51 mm) minimum
air space to combustible materials and always
check each pipe joint (inner and outer) to ensure
proper engagement. Check vertical alignment
of chimney so that it projects from the roof in
true vertical position.
Figure 26
Security's chimney sections do not need to be
screwed together. Additional reinforcement is
not necessary except in certain offset conditions
(refer to Page 16, Figure 38).
Figure 27
Note: Do not apply excessive pressure to any
subsequent chimney sections following the
stabilizer when installing. Ensure each subsequent chimney section is securely attached by
testing as noted in Step 4.
Step 6. Select the proper Security Chimneys
roof flashing based on pitch of roof.
Use chart below for selection:
Roof PitchFTF8
Flat to 6/12F8-F6
6/12 to 12/12F8-F12
Table 2
Figure 28
Step 7. Secure flashing by nailing along the
perimeter into roof using 8d nails or
equivalent fasteners. If shingled roof,
slide upper end and sides of roof flashing under shingles (trim if necessary),
seal the top and both sides of the
flashing to the roof with roof caulking.
Cover fastener heads with roof caulking
(Figure 29).
Figure 29
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
11
Step 8. The standard Security Chimneys FTF8
Roof Ridge
120°
CTD
Termination
Chimney
roof flashing assemblies include a
storm collar. Slide the storm collar over
outer chimney, rest on flashing spacers
and align with top surface of flashing.
Insert tab in slot, pull tight and bend
tab back over slot. Seal storm collar
to outer chimney with roof caulking or
mastic around entire circumference of
pipe. Also add extra roof caulking to the
tab/slot area to seal completely against
water penetration (Figure 30). Check
all joints very carefully to ensure no
water intrusion can take place.
Step 9. FTF locking bands, Model FLB, may
be required if the chimney extends
too high above the roof flashing. As
a general rule, if the chimney extends
more than 6' above the roof flashing,
the use of locking bands is advisable
to strengthen the chimney assembly.
Align the locking band at the chimney
joint. Locking bands wrap around pipe
joints equally covering the joints of both
pipe sections. Use the nut provided and
TIGHTEN snugly. Do not overtighten as
this might damage the chimney section
(refer to Figure 25).
Figure 32
Locking Band
Figure 30
Mastic
or Roof
Caulking
Note: If chimney extends more than 8' (2.4 m)
above roof surface, guy wires are also recommended. Use three (3) guy wires, attach to
locking band assembly, extend and secure to
roof in a triangular pattern (Figure 31). Guy wires
are not supplied by the manufacturer.
Figure 31
Step 10. Using an FTF8-CTD Round Termination:
1. Hold the CTD over top of last chimney section
(Figure 32).
2. Center inner slip section in inner flue pipe-
slip down.
3. Center outer locking section over outer flue
pipe. Push down until locking tabs are firmly
engaged.
4. Pull up slightly on CTD to ensure locking
joint has firmly engaged.
Note: It is recommended that all exterior
exposed metal fireplace components; such as
terminations, flashings, storm collars and/or
flue be painted with a premium quality, high
temperature, rust preventative paint designed
for metal. This is especially important when
installations are made in abnormally adverse
or corrosive environments; such as near lakes,
oceans or in areas with consistently high
humidity conditions. Consult the paint manufacturers instructions for proper preparation
and application.
12
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Figure 33
Less than
10' (3 m)
10' (3 m)
3' (914 mm)
Min.
2' (610 mm) Min.
3' (914 mm)
Min.
TEN FOOT RULE SUMMARY
The minimum chimney height above the roof
and/or to adjacent walls and buildings is specified by all major building codes.
If the horizontal distance from the peak of
the roof is less then 10' (3 m), the top of the
chimney must be at least 2' (610 mm) above
the peak of the roof.
If the horizontal distance from the chimney
edge to the peak of the roof is more than 10'
(3 m), a chimney height reference point is established on the roof surface located horizontally
10' (3 m) from the chimney edge. The top of the
chimney must be at least 2' (610 mm) above
this reference point. In all cases, the chimney
cannot be less then 3' (914 mm) above the roof
at the edge of the chimney.
The 2' in 10' rule is necessary in the interest
of safety, but does not ensure smoke-free operation. Trees, buildings, adjoining roof lines,
adverse wind conditions, etc., may require a
taller chimney should the fireplace not draft
properly (see Figure 33).
FTF8 CHIMNEY COMPONENT
CALCULATIONS
The minimum installed height of the completed
fireplace system is 15". The maximum system
height is 80' 0".
To determine the number of chimney sections
and chimney components required, follow
these steps:
1. Determine total vertical height of the fireplace
installation. This dimension is the distance
from the surface the fireplace sets on to the
point where smoke exits from the termination.
2. Determine the number of chimney compo-
nents required, except chimney sections.
This would include thimbles, extensions,
roof flashing, etc.
quired by subtracting total combined height
of all pre-selected components (fireplace
and chimney components from total desired
height).
Reference Vertical Elevation Chart and determine the number of chimney sections (quantity
and length) required. in Table 4 on Page 15.
SPECIAL OFFSET INSTRUCTIONS
To clear any overhead obstructions, you may
offset your chimney system using Security
Chimneys 30° offset and return elbows. Use
two elbows - an offset elbow to initiate the
offset and a return elbow to terminate it. A
30° offset elbow, angling in any direction, may
be the first component used off the top of the
fireplace flue collar. Maintain 2" minimum air
space to combustibles from chimney sections.
See Figures 41 and 42.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
13
A
1
C
1
B
1
B
2
C
2
A
2
Figure 34
Stabilizer
A
1
20' Max.
(6m)
B
1
10' Max.
(3m)
A
1
C
1
B
1
B
2
C
2
A
2
FTF8-E30
Return Elbow*
FTF8 Chimney
Sections
FTF8-30
Offset Elbow*
A
B
48"
(1219 mm)
* Part of Offset/Return Package, Model FTF8-ES30.
OFFSET ELEVATION CHART
A B FTF8-ES30 Number of FTF8 A B
Offset Height Offset/Return FTF8-S4 Chimney Sections Offset Height
together, or a section or sections of chimney
may be used between, but do not exceed 20'
(6.1 m) in total length between elbows (Figure
35). If sections of pipe exceed 10' (3 m) between
elbows, a chimney stabilizer must be used at
the midpoint. The stabilizer support straps
must be attached under tension (in shear) to
structural framing members above. When two
sets of offset elbows are used, the maximum
combined length of chimney used between
elbows cannot exceed 20' (6.1 m) (Figures 35 through 37). Example: If C1 = 10' (3m) then
C2 cannot exceed 10' (3 m).
If an offset exceeds 6' in length, each chimney
joint beyond the first 6' of offset to the return
elbow, must be secured by a No. 8 x 1/2" sheet
mental screw located at the underside of the
joint (Figure 38).
Maximum offset of the chimney system is 30°.
Two offset elbows must not be assembled to
form a 60° offset. However, two sets of offset
and return elbows may be used on a single flue
system, provided the total height of the system
exceeds 25' (7.6 m).
Return elbow support straps must be securely
attached under tension (in shear) to structural
framing members above.
OFFSET CALCULATIONS
1. Use Offset Chart to determine amount of
horizontal offset (A) and height (B) for various
chimney sections.
2. Use “Height of Chimney Only” column to
determine combinations of pipe used above
return elbow to achieve desired heights. Reference Components Effective Height Chart in
Figure elevation chart section.
3. Use Elevation Chart as job estimator only.
Add necessary firestop spacers and stabilizers
as required. Firestop spacers must be used as
shown in Figures 20 and 21 and stabilizers as
shown in Figure 27.
INSTALLING OFFSETS
First, review Offset Elevation Chart (Table 3)
and Figure 34 on Page 14.
OFFSET ELBOW ASSEMBLY
Offset elbows install the same as chimney
sections. First, snap the inner section INTO
the preceding inner section of flue. Check connection by pulling up slightly to ensure a tight
fit. Next, the outer sections snap locks OVER
the preceding outer section of chimney. Again,
check outer section by pulling up slightly to
ensure proper connection is made.
RETURN ELBOW ASSEMBLY
Return elbows install the same way as round
terminations and stabilizers:
Step 1. Hold return elbow over top of last
chimney section.
Step 2. Center inner slip section into inner flue
pipe-slip down.
Step 3. Center outer locking section over outer
chimney pipe-push down until locking
joint has firmly engaged.
Step 4. Pull up slightly on return elbow to
ensure locking joint has firmly engaged.
Step 5. Secure support straps to framing
members by nailing under tension in
sheer (Figure 40).
Figure 38
A 1/8" (3 mm) diameter hole must be drilled in
the chimney joint using a 1/8" (3 mm) diameter
drill. Hole should be drilled in center of joint
overlap (Figure 39). Be sure to drill only through
the outer chimney casting. Do not puncture
the inner flue.
Figure 39
Step 1. Determine the offset distance where
chimney is to pass through the first ceilingdimension “A.” To find this point on your
ceiling, first determine the center point for a
vertical chimney following the instructions for
vertical installation.
Measure height to the ceiling from the top of
fireplace-dimension “B.” Use Offset Elevation
Chart to find dimension “A.” Mark point where
you will drive your nail to show the center point
for your offset ceiling cut.
Step 2. Proceed by using the Straight Up Installation Instructions for cutting and framing
ceiling and roof openings.
Note: See “Framing and Dimension” Chart for
the sizes of the ceiling and roof openings. The
size of the roof opening varies with the degree
of pitch of the roof.
Figure 40
Note: The return elbow assembly performs the
same function as a stabilizer. Consider this when
determining the need for a stabilizer.
Note: Do not apply excessive pressure to any
subsequent chimney section following return
elbow assembly when installing. Ensure subsequent chimney sections are securely attached
by testing as noted above.
16
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
CHIMNEY OFFSET 30° THROUGH FLOOR
F8FS30-2
Firestop
Spacer
FTF8-S4
Stabilizer
2" (51mm)
Min. Air
Space
2" (51mm)
Min. Air
Space
30° Firestop
and Attic Above
10'
(3m) Max.
Attic Space
2" (51mm)
Min. Air
Space
30° Firestop
and Room Above
10'
(3m) Max.
Room Above
2" (51 mm)
Min. Air
Space
F8FS30-2
Firestop
Spacer
FTF8-S4
Stabilizer
Pivot Pin
Roller
Pin
Upper Door
Guide Track
Spring Clip
OR CEILING
It may be necessary to assemble the chimney
at 30° when passing through the floor or ceiling area. Use the F8FS30-2 firestop spacer as
shown in Figures 41 and 42.
Support the chimney at floor or ceiling penetration with a FTF8 stabilizer if distance of chimney
below ceiling is 10' (3 m) or more. Maintain 2"
(51 mm) minimum air space to combustibles
from chimney sections. The chimney must
pass vertically through the attic space.
Figure 41
Make a careful inspection of all parts before
installing the doors to ensure they are undamaged and complete. There will be two (2) glass
door assemblies for both sides of the CST38MH
fireplace.
Note:
• Design characteristics of a dual-opening
fireplace (whether masonry or factory-built)
may cause it to not draft properly and smoke.
For this reason, glass doors are required with
model CST38MH fireplaces.
• Upper door pivot pins can also be loosened
for adjustment purposes; however, it is easier
to loosen lower pins.
CAUTION
If an optional brass or stainless
door was purchased, remove the
plastic protective coating from
the doors before assembly and
installation. Failure to remove
the coating before first use will
result in damage to the finish.
Figure 43
Figure 44
GAS LINE INSTALLATION
Figure 42
GLASS DOORS
The Fireplaces require the use of the standard
glass doors (provided). The use of any other
non-listed door on these fireplaces may result
in a potential fire hazard and is not recommended.
CAUTION
Do not touch the doors with your
hands while the fireplace is in
use. Always use door handles.
Doors will become very hot when
fireplace is in use.
WARNING
These fireplaces should be operated only with the doors fully
closed (Figure 44).
The Fireplaces have been approved to accept
a 1/2" (13 mm) gas line for an approved gas
appliance. Always have the appliance installed
by a qualified, licensed plumber in accordance
with all local building codes. The gas line may
enter either end of the fireplace.
CAUTION
Plumbing connections should
only be performed by a qualified, licensed plumber. Main
gas supply must be off when
plumbing gas line to fireplace
or performing service.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
17
If you’re installing a gas line, connect it before
12"
(305 mm)
Min.
6"
(152 mm)
Finished Wall
Spacer
Combustible
Mantel
and Trim
12"
(305 mm)
Max.
False
Header
1 ¹⁄₂"
(38 mm)
Fireplace Opening
the fireplace is framed and enclosed in the
finished wall. The gas knockout is determined
by a 1-1/8" (29 mm) round indentation located
at the bottom and slightly off center in the
side refractories. THE KNOCKOUT IS ALWAYS
REMOVED FROM INSIDE THE FIREPLACE. DO
NOT REMOVE THE KNOCKOUT UNLESS YOU
ARE INSTALLING A GAS LINE. If removal is at-
tempted from the outer wrapper, side-refractory
damage may occur. With a medium-sized hammer, lightly tap the surface of the indentation.
The refractory material is very thin in this area
and is easily removed. Once a small hole has
been made, continue tapping until you have
reached sufficient diameter for the gas line to
fit through. The entire knockout does not have
to be removed. Remove insulation in the gas
line channel.
Install a 1/2" (13 mm) gas supply line through
fireplace wall for connection to a decorative
gas appliance inside the firebox. Outside, the
gas supply line must connect to a gas shut-off
valve usually recessed flush into the wall or floor.
The valve should be controlled by a removable
valve key for safety.
Always plumb gas line installation per local
codes. Check all connections using a gas leak
test solution (also referred to as bubble leak
solution). Note: Using a soapy water solution
(50% dish soap, 50% water) is an effective
leak test solution but it is not recommended,
because the soap residue that is left on the
pipes/fittings can result in corrosion over time.
Never test any gas line connection with a match
or open flame.
IMPORTANT
Repack insulation material in
square hole around gas line,
interior and exterior, to seal.
For all areas, this provision is intended only
for connection to a decorative gas appliance
incorporating an automatic shut-off device and
complying with the standard for Decorative Gas
Appliances for installation in vented fireplaces,
ANSI Z21.60. Install in accordance with the
National Fuel Gas Code, ANSI Z223.1.
COLD CLIMATE INSULATION
If you live in a cold climate, it is especially
important to seal all cracks around the fireplace and wherever cold air could enter the
room with noncombustible material. Surround
material must be caulked where it meets the
black metal facing of the fireplace to avoid
cold air intrusion. Use noncombustible caulking material only on fireplace facing to seal.
Also, the outside air inlet duct should be
wrapped with noncombustible insulation to
minimize the formation of condensation. Do
not place insulation materials directly against
the chimney sections.
Note: 2" (51 mm) air space must be preserved
for all materials extending for any continuous
length adjacent to the chimney.
It is especially important to insulate between
the studs of an outside chase cavity and under
the floor if the floor is above ground level. Do
not place insulation directly against the fireplace
or chimney system.
FIREPLACE FINISHES
Mantels and Trim
It is sometimes best to frame your fireplace after it is positioned and the chimney is installed.
Frame enclosure for chimney and fireplace with
2 x 4’s (or heavier) lumber.
Note: The header may rest on the two (2) metal
top spacers on top of the unit but the header must
not be notched to fit around the spacers.
In all installations, combustible mantels and
trim may be installed 12" (305mm) above the
opening as per NFPA 211-latest edition. and
Figure 45. If a mantel is of a noncombustible
material, it is exempt from the requirements as
long as it does not interfere with the operation
of glass doors.
Figure 45 - Mantel Clearances
Hearth Extensions and Wall Shields
A hearth extension must be installed with all
fireplaces. Its purpose is twofold. It protects a
combustible floor in front of the fireplace from
both radiant heat and sparks and it distinguishes
the prescribed hearth extension area from other
non-protected surfaces.
The hearth extension must extend beyond
the front and both sides of the fireplace side
openings. Use a hearth extension constructed
of a durable noncombustible material having
an equal or better (lower k value) insulating
value of k = .84 BTU IN/FT2 HR °F or a thermal
resistance that equals or exceeds r=1.19 HR
°F FT2/BTU IN. A minimum 3/8" (10 mm) thick
noncombustible material is all that is required
over a noncombustible or slab floor.
If there is a continuous perpendicular side
wall closer than 18" (mm) from the fireplace
opening, it must be protected with a 40" x 40"
x 1/2" (1016 mmx 1016 mm x 13 mm) wall
shield (see Figure 46) constructed of a durable,
noncombustible material having an equal or
better (lower k value) insulating value than k =
.84 BTU IN/FT2 HR °F. A continuous protected
side wall can not be closer than 8" (203 mm)
from the fireplace opening.
Secure the hearth extension to the floor to
prevent possible shifting.
18
CAUTION
When using the decorative gas
appliance, the fireplace damper
must be set in the fully open
position.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
B
A
C
C
Protected
Side Wall
D
40"
40"
A
B
D
C
C
Wall Shield Required
Where Less Than 18".
Adjacent Wall is Never
Allowed Closer
Than 8".
Hearth Extension Dimensions
A16"
B28-1/2"
C8"
D44-1/2"
Note: To convert inches to millimeters divide by .03937.
Figure 46
Methods of Determining Hearth Extension and Wall Shield
Equivalents - To determine the thickness required for the alternate
material when either the "k" value or "r" value is known, use either the
k formula or r formula.
Example: If Micore 160 is to be used for the hearth extension fireplace,
how thick must this material be?
kM = k value per inch of alternate material
rM = r value per inch of alternate material
TM = minimum thickness required for alternate material
TS = standard thickness of the alternate material
kL = k value per inch of listed material
rL = r value per inch of listed material
TL = minimum thickness of listed material
Note: An asterix "*" indicates, it is a value taken from Table 5.
Using the k formula:
Minimum k-value (per Inch) of Specified min.
thickness of = alternate material (kM) x thickness
alternate k-value (per inch) of listed
material (TM) of listed material (kL) material (TL)
TM (inches) = kMx TL
*.84
TM (inches) = *.35 x 1"
*.84
.416 (inches)= .416 x 1"
Answer - The minimum required thickness of the Micore 160 is .417," therefore round up to nearest standard thickness available which is 1/2."
Using the r formula:
Minimum r-value (per Inch) Specified min.
thickness of = of listed material x thickness
alternate r-value (per inch) of listed
material of alternate material material
TM (inches) =
r
Lx T
rM
TM (inches) = *1.19 x 1"
* 2.86
.417 (inches)= .416 x 1"
Answer - The minimum required thickness of the Micore 160 is .417," therefore round up to nearest standard thickness available which is 1/2."
Listed Material
k (per inch) r (per inch)Listed Min.Thickness
Listed Material .84
** Approved Alternate Materials for Floor/Hearth Protection
** If the hearth extension material(s) that is intended to be used is NOT listed
on Table 5, the material can still be used if the material(s) is noncombustible.
However, the manufacturer of the material must provide either the listed k-value
per inch or r-value per inch with listed thickness so that the minimum thickness
required for the hearth can be calculated (per instructions on this Page and/or
L
as specified in the NFI Certification manuals).
Note: Also see NFI (National Fireplace Institute) Certification Manuals showing
other exceptable caluculation methods and acceptable alternate materials
which can be used.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
19
Maximum Thickness of Hearth Extension
when Fireplace is on the Floor.
5 ⁵⁄₈"
*
(143 mm)
Max.
*
5 ¹⁄₈" (130 mm)
If “C” Style Door
Is Used.
8" (203 mm)
11 ³⁄₈"
(289 mm)
30˚
Combustible
Materials Allowed
in Shaded Area
1" (25 mm)
Minimum Distance
to Protected Side Wall
4 ⁵⁄₈"
(118 mm)
18"
(457 mm)
Minimum Distance
to Unprotected Side Wall
Calculating Minimum Thickness if
Multiple Materials are Used
At times it is important to know what
combination of materials are acceptable for use
as floor protection. The “R values” are used to
determine acceptable combinations of materials
because “R values” are additive where r and k
values are not.
“R value” = 1/k = "r" x thickness of material
used
Example: Given that the required “R value”
for a suitable floor protector used must be
equal to or greater than:
“R” = rL x TL = 1.19 x 1” = 1.19."
If it is desired to elevate a marble hearth
extension to a level of 5” or more above
the floor surface. What combination of
noncombustible materials can be used to
accomplish this?
If common brick is used so that the 3-1/2”
dimension is the height, “R” for the common
brick becomes:
brick
“R”M = rM x TS = 0.20 x 3-1/2" = .70
WARNING
The crack between the fireplace
and the hearth extension must be
sealed with a noncombustible
material.
WARNING
When installing hearth extension
in front of a non-circulating fireplace model, the fireplace must be
raised if height of hearth extension
exceeds 5-3/4" above the bottom of
fireplace (Figure 47).
When installing the hearth extension be careful not to block the
heat-circulating air inlet grill on
circulating models.
Only noncombustible materials like marble,
stone, tile, brick, etc. may overlap the black
front facing, but be careful not to interfere
with the operation of the glass doors. Seal
all joints between the black facing and wall
surrounds to prevent cold air intrusion. Use
noncombustible caulking material only to seal
the black metal facing to the surround material
on the finished wall.
Combustibles may also project beyond the
sides of the fireplace opening as long as they
are kept within the shaded areas, as illustrated
in Figure 48.
Using 1/2” of mortar to set the brick, “R” for
the mortar is calculated as follows:
“R”M = rM x TS = 0.20 x 1/2" = .10
Next, a 3/4" marble slab set in 1/2" mortar covers the brick, “R” for the marble and mortar
becomes:
“R”M = rM x TS = 0.05 x 3/4" = .038
“R”M = rM x TS = 0.20 x 1/2" = .10
The sum of all “R values” is: .70 + .10 +. 038
+ .10 = .938
This would NOT be an acceptable combination
of material for the hearth extension since the
total calculated “R value” of the materials used
is under the required “R value” of 1.19. An
additional layer of insulating materials must
be used.
Note: Also see NFI Certification Manuals for
expanded explanation on calculating “R values” when multiple materials are used.
mortar
marble
mortar
Figure 47
FINISH TO YOUR TASTE
There are a wide variety of “finished looks”
for your Fireplace from formal wall decor with
elaborate mantels to rustic wood paneling or
warm brick facings.
Figure 48
ACCESSORY PARTS AND COMPONENTS
LIST FOR MODEL CST38MH
The accessory parts and components shown on
Pages 21 and 22 are to be used only with your
CST-38MH fireplace system. Separate installation instructions are packaged with all combustion air kits and chimney terminations.
If you encounter any problems or have questions concerning the installation or application
of this system, please contact your distributor.
For the name of your nearest distributor, please
call 1-800-953-6669.
The manufacturer reserves the right to make changes at any time, without notice, in design, materials, specifications, prices and also to discontinue colors, styles and products. Consult your
local distributor for fireplace code information.