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Page 8 September 1, 2008
Isle Royale Wood Stove
250-5763C
Calculating Alternate Floor Protection

Material

Thermal Conductivity: k value
The k value indicates the amount of heat (in BTU’s) that will ow
in 1 hour through 1 square foot of a uniform material 1 inch thick
for each degree (F) of temperature difference from one side of
the material to the other. The LOWER the k factor means less
heat is being conducted through the non-combustible material
to the combustible material beneath it. The k value of a mate-
rial must be equal or smaller then the required k value to be
acceptable.
(BTU) (inch)
(foot2 (hour) (oF)
Thermal Resistance: R value
The R value is a measure of a material’s resisteance to
heat transfer. R value is convenient when more than one
material is used since you can add the R values together,
whereas you can not do this for k value. The HIGHER the R
factor means less heat is being conducted through the non-
combustible material to the combustible material beneath it.
The R value of a material must be equal or larger then the
required R value to be acceptable.
Converting k to R:
Divide 1 by k and multiply the results times the thickness in
inches of the material.
R = 1/k x inches of thickness
Converting R to k:
Divide the inches of thickness by R.
k = inches of thickness/R
Calculatons:
Example: Floor protection requires k value of 0.84 and 3/4 inch
thick.
Alternative material has a k value of 0.6 and is 3/4 inch thick.
Divide 0.6 by .75 = k value of 0.80. This k value is smaller than
0.84 and therefore is acceptable.
WHEN LOCATING YOUR STOVE consider safety, conve-
nience, trafc ow, and the fact that the stove will need a
chimney and chimney connector. It is a good idea to plan
your installation on paper, using exact measurements for
clearances and oor protection, before actually beginning the
installation. If you’re not using an existing chimney, place the
stove where there will be a clear passage for a factory-built
listed chimney through the ceiling and roof.
AVOID FIRE: Maintain the designated clearances to combus-
tibles. Insulation must not touch the chimney. You must main-
tain the designated air space clearance around the chimney.
This space around a chimney is necessary to allow natural
heat removal from the area. Insulation in this space will
cause a heat buildup, which may ignite wood framing. NOTE:
Clearances may only be reduced by means approved by
the regulatory authority having jurisdiction.
WE RECOMMEND that you have a qualied building inspec-
tor and your insurance company representative review your
plans before and after installation.
LOCATING YOUR STOVE