When you see a stone fireplace, it might evoke a strong emotion in you for a number of reasons. To a very slight degree I think it’s hard coded into our DNA, as stones have been used for hundreds of thousands of years to contain campfires and indoor fires in castles and cottages. It’s perfectly normal to see outdoor fireplace stone used both in a decorative way as well as crudely stacked to contain flames and embers.
Outdoor stone fireplaces are a very popular amenity you might discover if you tour model homes in the Southwest and far West. Visit the Midwest and you’ll see quite a few of these in backyards. GIs returning from World War II took a fancy to outdoor barbecues that also served as a small fireplace. There is a difference indeed as an outdoor fireplace doesn’t really have a flat cooking surface like a barbecue.
I happen to have a cast-stone fireplace in my New Hampshire lake house. Cast stone is simply artificial rock made from concrete. When you pour pigmented concrete into special rubber molds, you can create castings that will fool, at a distance, all but the most seasoned geologist. Some cast stone is remarkably realistic.
Stone-fireplace designs are as plentiful as leaves on a forest floor in autumn. I’ve seen spectacular stone fireplaces that are 20 or more feet high, rustic stone fireplaces that have custom-carved stone-fireplace mantels and quaint stone fireplaces in modest homes. You can use flat stone, small rounded boulders or coarse volcanic rock. It’s just a matter of the style and the type of rock that matches the color scheme and feel of the room.
When you start to think about your stone fireplace surround, be sure to consider the scale of the stone with respect to the size of the room and the amount of stone that’s you’ll see. If you plan to have just a small amount of stone exposed in the room, and the ceiling is low, it may be better to go with a smaller-sized stone. Scale is everything. If in doubt, be sure to consult with a residential architect or interior designer. The best way is for you to go see as many stone fireplaces as possible taking note of those that look best to you and those that feel too heavy or awkward. Take stone fireplace pictures and great notes. Once you discover the stone fireplace of your dreams, recreate it as closely as possible in your home.
I’ve seen some fascinating stone fireplace surrounds. Perhaps the most impressive one I’ve ever seen can be found in the lobby of the Grove Park Inn located in Asheville, North Carolina. The lintel stone that bridges the top of the fireplace is massive. The scale of the stones is exactly in keeping with the size of the huge lobby. There’s a natural stone fireplace at each end of the lobby. They burn logs in these massive fireplaces, not cordwood!
Keep in mind that the stone used in a stone veneer fireplace needs to be durable and not susceptible to heat damage. Limestone, granite and dense metamorphic rocks can stand up to heat with no issues. Avoid soft rocks, slate or any other rock that crumbles fairly easily. The inside of the firebox should absolutely be built with hard firebrick set in fireclay, not mortar. Mortar used in between firebrick almost always crumbles when subjected to the repeated heat of fires. Fireclay is the preferred material as the joints between the brick are small, and the fireclay tends to vitrify with each fire.
Your stone fireplace hearth should be planned with great care. It needs to meet the minimum building-code requirements, but it also needs to be practical. If you decide to have a raised hearth, be aware that they can be too high or too low. I would never have a hearth higher than 17 inches and not much lower than 6 inches. If you can’t visualize your hearth, have a carpenter make up temporary hearth using plywood. Create the actual firebox using large sheets of cardboard for scale. Sit on the plywood hearth to see if it’s comfortable. Try to load wood and tend the imaginary fire to make sure the hearth is not too deep.