18
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
Using 1/2” of mortar to set the brick, “R” for the mortar is calculated as follows:
mortar
“R”M = rM x TS = 0.20 x 1/2" = .10
Next, a 3/4" marble slab set in 1/2" mortar cov- ers the brick, “R” for the marble and mortar becomes:
marble
“R”M = rM x TS = 0.05 x 3/4" = .038 mortar
“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 val- ues” when multiple materials are used.
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
When installing the hearth exten- sion be careful not to block the
Max. Thickness Of Hearth Extension When |
Fireplace Is On The Floor |
Figure 43 |
Secure the hearth extension to the floor to prevent possible shifting.
FINISH TO YOUR TASTE
There are a wide variety of “finished looks” for these fireplaces, from formal wall decor with elaborate mantels to rustic wood paneling or warm brick facings.
Only noncombustible materials like stone, tile, brick, etc., may overlap the black front facing. Do not extend these materials beyond the black facing and into the firebox area. Be sure not to interfere with the installation and operation of glass doors or block the upper or lower grilles. Seal all joints between the black facing and wall surrounds to prevent air intrusion. Use noncombustible caulking material only to seal the black metal facing to the surround material on the finished wall.
Combustible materials may project beyond the sides of the fireplace opening as long as they are kept within the shaded areas illustrated in Figure 44.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Combustible |
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Materials |
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Allowed In |
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| Fireplace |
Shaded Area |
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“Safe Zone” |
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| 1" |
| 7" |
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| 45 |
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12" |
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| Min. Distance To |
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| 7" | |
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| Protected Side Wall | |
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| 12" |
| Min. Distance To |
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| Unprotected Side Wall | |
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Figure 44 |
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ACCESSORY PARTS AND COMPONENTS LIST FOR MODELS BCD36MH AND BC36MH
The accessory parts and components shown on Pages 18 and 19 are to be used only with your BCD36MH or BC36MH fireplace system.
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 call:
LHP
1110 West Taft Avenue
Orange, CA 92865
INSTALLATION COMPONENTS
The following items are available for use in the installation of this appliance.
Blower Kit is installed as a standard component on model BCD36MH (optional kit for model BC36MH)
Forced Air Blower Kit | 36L32 | BFK36 |
