Majestic Appliances EWF36A installation instructions Common Materials and Factors

Vermont Castings EWF36A

The top of insulation must be covered with a non- combustible decorative covering or a piece of .018” minimum sheet metal, to protect hearth extension material. (Fig. 25)

Secure the hearth extension to the floor to prevent shifting, using trim molding or other similar means at three (3) outer edges. Seal crack between the fireplace hearth and hearth extension with a noncombustible material. (Figs. 24 and 25)

WARNING: Hearth extension must be installed in accordance with Figure 24. Top of hearth extension must be level with bottom of fireplace.

Example of Determining Hearth Extension Equivalents

To determine the thickness required for any new material:

NEW	K of new material (per inch)	thickness
required =		x of listed
thickness	K of listed material (per inch)	material

Example for Common Brick

T (new) = 5.0/0.458 x 0.50 in. = 5.46 in. (new required thickness).

Alternate noncombustible materials may be used providing the (total) thermal resistance (Rt value) of the alternate material employed is greater than or equal to R = 1.09 Thermal resistance (R) or thermal conductiv- ity (K), may be obtained from manufacturer of the material. Factors are related by the formula K = 1/R. (Fig. 23)

T = given thickness

R = thermal resistance for a given thickness (T) K = thermal conductivity

Noncombustible material with a lower R value may be used, provided thickness of material is sufficiently greater to maintain an equivalent (total) thermal resis- tance (Rt).

COMMON MATERIALS AND FACTORS

Wall Covering

Noncombustible

Decorative

Facing

Seal all cracks between fireplace surround (steel) and wall materials with noncombustible material.

Cast Front

Noncombustible

Decorative

Covering

FP1202

2 x 4 Header - Do not notch at standoffs

NOTE: No material may cover black cast face.

Safety Strips - Must be overlapped 1/2” minimum

MATERIAL	K*	R	MINIMUM
			THICKNESS

EH2416	1.0 in.**
(Majestic Products 0.916 2.18
Company)
Common Brick 5.0 0.10	5.46 in.**
R Value is for ¹⁄₂ inch.
* Units of K = BTU/SQ FT/HR/ßF/IN
** Thickness of Listed Material		FP533ADD

Fig. 23 Hearth extension material factors.

Fig. 24 Sealing gaps.

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