All SIERRA Hearthstoves require floor protection when
installed on a combustible surface. For hearthstoves
without the ash pan or catalytic option, you must place your
stove on a anon-combustible floor protector equivalent to
two 3/8' layers of asbestos covered with one sheet of 24
gauge minimum sheet steel. The floor protector must
extend 16" in front of the door side, 12" from the rear side
on rear vents stoves, 8" from rear side on top vent stoves,
8" from the other side of the stove, under the chimney
connection and 2" beyond each side.
MINIMUM CLEARANCE TO COMBUSTIBLES
Rear Vented
Top Vent
Units To
18"
A
Side Wall
18"
26"
B
Back Wall
18"
16"
C
Corner
12'
Flue To
31"
D
Side Wall
30"
18"
E
Back Wall
19"
18"
F
Corner
24"
There are listed non-asbestos floor protectors available at
your local woodstove supplier.
Recommended floor protection is based on a standard of
3/8" Inch of asbestos millboard or equivalent. This is used
as a standard only.
The k, C or R factor that correlates with the floor protector
material used during the test if the room heater is not
provided with a floor protector. The units of measure for k,
C and R factors shall use the same applicable units.
Directions and examples on how to use alternate materials
and how to calculate equivalent thickness shall be shown.
An easy means of determining if a proposed alternate floor
protector meets requirements listed in the appliance
manual is to follow this procedure:
1. Convent specifications to R-value
a. R-value is given - no conversion is needed.
b. K-factor is given with a required thickness (T) in
inches: R=1/k+T
c. C-factor is given: R=1/C
2. Determine the R-value of the proposed alternate floor
protector.
a. Use the formula in step 1 to convert values not
expressed as “R”.
b. For multiple layers, add R-values of each layer to
determine the overall R-value.
3. If the overall R-value of the system is greater than the R-
value of the specified floor protector, the alternate is
acceptable.
EXAMPLE:
The specified floor protector should be 3/4 inch thick
material with a k-factor of .84.
The proposed alternate is 4" brick with a C-factor of 1.25
over 1/8" mineral board with a k-factor of .29.
Step 1: Use formula above to convert specification to
R-value. R=1/kT = 1/0.84 x .75 = .893
Step 2: Calculate R of proposed system.
4" brick of C - 1.25, therefore
R brick = 1/C = 1/1.25 = 0.80
1/8" mineral board of k+ 0.29, therefore
R min.bd. = 1/0.29 x 0.125 = 0.431
Total R = R brick + R brick + R mineral Board
= 0.8 + 0.431 = 1.231
Step 3: Compare the proposed system R of 1.231 to
specified R of 0.893. Since proposed system
R is greater than required, this is acceptable.
Definitions:
3/8 inch millboard has a “K” factor of 0.84. The newer
substitute CERAFORM board has a “K” factor of 0.21.
Your floor protector must have an equivalent or better “K”
factor than the above recommendations.
WARNING: The installation of this stove must comply with
state and local requirements and be inspected by the state
or local building inspector, if required.
This stove is not approved or recommended for use in
mobile homes.
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