Gas Fireplace Hearth Size

This particular gas fireplace requires a non combustible hearth with a thermal rating of r 1.

Gas fireplace hearth size.

The thickness of the hearth should be a minimum of 4 inches. The bottom of the damper should be a minimum of 8 inches above the top of the fireplace opening. This part of the fireplace is called the throat. A hearth must extend a minimum of 300mm 12 inches in front of the fire or stove and 150 mm 6 inches to the side of the fire or stove see diagram 4.

Units that have sealed fronts direct vent units may allow less of a hearth per manufacturer recommendations based on overall size and temperature of the sealed unit. The hearth also needs to extend 8 inches to each side of the opening. Or bigger the front extension needs to be increased to at least 20 and the side extensions to at least 12 beyond the fireplace front. Under some circumstances the minimum depth of a hearth plate is 12mm see below.

So while i am not personally aware of any gas fireplace that requires hearth protection if it is raised 6 off of the floor it will be important to consult the installation manual for the specific fireplace you are installing. The hearth must project at least 36 inches out in front of the fireplace if the fireplace doors open to expose the flames to open air. A fireplace hearth should extend at least 16 past the front edge of the fireplace and at least 8 beyond each side of the fireplace opening. Where the fireplace opening is 6 sq.

If your damper is not at least 8 inches above this spot you will have smoking problems for sure. I urge you to read the pamphlets i have mentioned from the brick industry association. Be sure to check with a professional what size of hearth is required for your particular location and fireplace situation. How deep should a hearth be.

Side clearance to combustibles.