Homeowner and landscape designer Nancy Driscoll wants to add a Mexican fireplace to her backyard to provide a fun, relaxing place to entertain. Driscoll also explains that the style of a Mexican fireplace should suit the style of the home it accompanies. (Formal-style homes are best enhanced with higher, formal-style fireplaces, while ranch style, Spanish or contemporary homes look best with a more casual style.)
Here, an informal style not too high off the ground is chosen to suit the family's casual approach to entertaining, as well as the architecture of their ranch-style home. Additionally, the lower height will allow Driscoll's children to access the fireplace for roasting hot dogs and marshmallows. Driscoll explains that it's extremely important to choose a safe site for any outdoor fireplace, one with no flammable branches or plantings that will get in the way. The best choices are paved areas or well-watered lawns; in dry areas, it's a good idea to add a spark arrester(a hood that fits over grills to catch sparks).
Driscoll explains that this project has a modest price tag of about $800 for the do-it-yourselfer; a professional installation will cost around $2,000. However, Driscoll also points out that the physical labor involved in handling the weight of the flagstone makes this project a considerable challenge--on a difficulty scale from 1 to 5, with 5 being the most difficult, Driscoll rates it a "5."
Step One: Laying the Foundation
To get started, the footing is excavated first. The crew, led by stonemason Miguel Raiz, uses a length of mason's line attached to a stake in the center of the circular site of the fireplace to draw three concentric rings with landscaper's spray paint. The first ring marks the inside wall of fireplace, the second ring marks outside of that wall (about a foot outside the innermost circle) and the third ring indicates the boundary of the inner flagstone surround (other pieces of flagstone will be laid on sand farther out in the lawn.
Next, Raiz and the crew dig out the one-foot space of grass between the two smaller circles, digging about six inches deep. This creates a sunken area for the concrete footing that will support the wall.
Then, the dug-out area is fitted with Number Four re-bar, bent into two rings--one is a few inches wider than the other--and held together with wire. The crew uses a special tool to tighten the wire that binds the two rings, but it can also be twisted and secured by hand. Once the two rings are securely fastened together, they are laid inside the dug-out ring to provide reinforcement for the footing.
Finally, the hole is filled with concrete and smoothed on top with a trowel to create a smooth surface to complete the footing.
Step Two: Building the Walls
The inside wall is built with volcanic rock, which will expand and contract with heating and cooling, and won't crack like other types of rock. It's also more cost efficient than firebrick, which is another option for fireplace walls. Volcanic rock also features an attractive natural appearance.
While the ring of concrete footing is still wet, Miguel and his crew remove the turf in four evenly spaced areas inside the ring. These areas will be fitted with four stones that will serve as the supports for holding the bottom charcoal grill (a standard 36" round grate). The most important consideration here is to ensure that the tops of these stones are perfectly level once they're in place, so the grill doesn't tilt.
With the grill panel in place, the crew begins building the fireplace wall by laying the first layer of stones around the grill panel. The mortar is applied along the outside of the rocks where it won't show (the exterior will eventually be covered with the flagstone veneer.)
About eight to 10 inches above the lower grate, the crew repeats the process to create a support for the upper grill panel. (The two grills should be relatively close together so the heat from the charcoal can heat the food on the upper grill .)
After the mortar is allowed to cure overnight, it's time to add the flagstone veneer . Here, two types of rock are used for this step. The first is a smaller size rock , which features tones of rose, buff and gray and will be used for the veneer of the fireplace. The second type of rock-blush-colored Arizona flagstone--features larger, thicker pieces that will work well for the flat surround that borders the fireplace.
Before adding the veneer, the space between the rock wall and outermost ring is dug out (a few inches deep is sufficient) to make the fireplace easily accessible. Then, the mortar is mixed with a color additive that complements the sandy hue of the rocks. The crew also adds a liquid concrete bonding adhesive (available in home improvement centers) to the mortar to ensure that the rocks of the veneer firmly adhere to the volcanic rock of the fireplace wall.
Driscoll explains that creating the veneer is actually quite easy; simply choose rocks that fit together relatively well and use a hammer and chisel to modify edges as needed for a better fit. Use about one inch of mortar on the backs of the stones to hold them in place, and position rocks as desired along the top of the wall. After checking to make sure the rocks on the top edge are level, fill in the spaces between with mortar.
For the flat surround, fill the dug out ring with concrete and allow it to dry for at least 24 hours. Then, lay out pieces of flagstone on the concrete with about 1/2" to 3/4" spaces in between. The stones along the inside of the ring should be fitted relatively closely against the veneer of the fireplace wall. After the mortar has set for about 30 minutes, go back over it with a soft brush or a stick and a sponge to clean and smooth the finish. (This step should also be used for the veneer itself.)
To plant the area around the fireplace, avoid any large plants that might get too close to the heat when the fireplace is in use. Here, Driscoll added two rectangular terra cotta containers of herbs, which include several varieties of rosemary, French thyme, chamomile, Chinese cilantro and parsley. The containers are placed on the large outer stones that border the fireplace surround.
In the patio area, Driscoll adds some colorful bedding plants along the edges as well as several container plants against the walls. She also uses several espaliered plants on trellises, including one camellia pruned to look like a tree and another that is allowed to grow more naturally. Driscoll says that simply attaching the plants to a trellis with plastic twist ties and trimming any forward-growing branches will create an attractive espaliered plant.
Step Three: Completing the Outer Flagstone Surround
To lay the large stones that form the outer surround, choose thick, flat pieces. Once the pieces are arranged as desired, score around the edge of each piece with a shovel. Next, remove each stone and dig out the areas about once inch deeper than the thickness of the stones. Then, lay down an inch of builders' sand in each cavity and put the stones back in place, agitating them slightly back and forth to eliminate air pockets.
For more great flagstone accents, consider adding a veneer to an existing square column (such as a gate post), or build a mailbox support with concrete blocks and finish it with a veneer.
Step Four: Project Review
With Driscoll's Mexican fireplace complete and the patio boasting a beautiful array of new plantings, all that's missing are the barbecue guests!
)
)
