With lighter weights, lower material costs, and potentially easier applications than the real McCoy, manufactured stone is an increasingly popular choice for building pros.
"You'd be hard-pressed to find a residential development that doesn't have some sort of stone veneer on it some place," says Dave Barrett, president of United Stone Veneer.
Made of a cement mix shaped by molds and colored by chemical pigments, manufactured stone is adhered to surfaces rather than anchored. Although used mostly as an accent on a home's exterior, it's increasingly installed as cladding or as an interior detail, says Michael Weber, director of residential programs for the Portland Cement Association.
The initial appeal of manufactured stone started with fireplaces. Now its use has expanded to include exterior cladding, accents, and even wine cellars and outdoor spaces.
Because of its light weight, manufactured stone is increasingly popular in remodeling, where homes may lack the structural reinforcement to support the load of natural stone, Len Przybylski, owner of Trilite Stone, says.
The product often is installed by masons, but can be applied by other contractors. Bill Dentinger, a mason from B&D Associates in St. Paul, Minn., who installs natural and manufactured stone, questions manufacturers' claims that the faux stone is cheaper and easier to install. While the material cost is lower, "we haven't noticed that the labor's gotten that much cheaper," he comments.
Manufactured stone sales have increased almost every year since the product's introduction in the 1960s, says Weber, with its greatest spike during the past seven or eight years. But usage remains low. By the end of 2004, manufactured stone was just more than 2.4 percent of exterior cladding square footage for single-family detached homes, according to the Portland Cement Association.
Despite growing acceptance, homeowners in large areas of the country–particularly those rich in naturally occurring stone–remain unfamiliar with the product. "The first hurdle you have with someone who's not at all familiar with building products is, 'Why manufactured stone?'" says Geoffrey Turner, owner and president of Crown Hill Stone, a manufactured stone producer. "But then you explain the advantages."
Originally, colors were mixed in a variety of "garage-type operations" by dabbing powder containing iron-oxide pigments into molds, says Barrett. But the hues lacked patina and created a homogenous look. "It was very honest and very gray, brown, beige, and charcoal," says exterior color consultant Miriam Tate, of the Costa Mesa, Calif.-based Miriam Tate Co., which works with Owens Corning's Cultured Stone.
In contrast, today's shades consist of primary and tertiary colors overlaid to create depth. Although earth tones remain constant, new purples, burgundies, and greens add vibrancy, Przybylski says.
For instance, Cultured Stone's Bucks County offers a range of natural colors with an overall green hue. Bucks County and chardonnay, a combination of rose and camel tones, are the company's two best-selling products, says Bob Heath, marketing leader for Owens Corning Cultured Stone. Meanwhile, Crown Hill Stone has seen a trend toward lighter colors and blends, says Turner.
Owens Corning is applying the same techniques to manufacturing faux bricks under the name Cultured Brick. "In clay brick, often the colors are limited to the clay and raw materials in the burning process. We can create any combination of colors without any reliance on a raw material," Heath says.
Eldorado Stone also is introducing a new brick line, which sports colors that are worn and weathered.
In the Mix
For a variety of reasons, companies add synthetic fibers, water repellants, and other elements into the cement mix. For example, Crown Hill uses a synthetic fiber to improve durability and strength–particularly during transport, Turner says.
Depending on its intended use, some manufacturers coat the faux stone with a sealant. Przybylski recommends using sealants for fireplaces in high-traffic family rooms to prevent chips and stains. A number recommend applying the sealant on site. Turner says, "It will have better protection and greater penetration if it's applied in the field."
An added bonus of field-applied sealant is protection for the mortar, which is a stone veneer's weakest point, according to the Crown Hill Stone executive. Applicators should coat the sealant uniformly over the stone and mortar but avoid over-spraying.
A Variety of Looks
The evolution of manufactured stone has been driven in part by the variety of architectural styles appearing on streets across the country, Tate says. Today manufacturers offer a variety of looks, from field stone that might complement Tuscan-style architecture to more chiseled, honed stones that recall a castle.
Manufacturers also are blending stone shapes, such as pairing a mountain ledge consisting of thin, jagged pieces with larger, round field stone to break up horizontal lines, Przybylski says.
Colorful mortar is another way to create a unique look, Tate says. While a prairie-installed dry-stack ledgestone might be installed with no visible mortar, a dress fieldstone can be fully mortared in a complementary shade such as butterscotch.
Applying manufactured stone in a balanced way remains a universal challenge, says Tate. For example, builders should avoid adhering the faux stone to only one side of a house, which results in all color and textural weight being overdone on that side and underdone on the others, she says.
Although sales at United Stone Veneer have increased 40 percent to 75 percent each year since 1999, Barrett questions how long the industry can sustain that momentum. Instead, he predicts steady, stable demand.
As for aesthetics, Tate says there is room for even more styles, predicting formal, more precise stone arrangements. Additionally, the increasing popularity of contemporary architecture will provide a "blank canvas" for sculptural, cleaner lines in stone veneers, she contends.
Owens Corning. Cultured Stone River Rock, shown in a Mackinac finish, is intended to mimic the round and random shapes of stones tumbling downstream in Northern forest riverbeds, says the manufacturer. 800-255-1727. www.culturedstone.com.
United Stone Veneer. Styled to mimic the appearance of traditional European cobblestone streets, Cut Cobblestone manufactured stone is available in nine varieties. Shown in Leighton, its array of hues such as chardonnay, shade mountain, and Pennsylvania limestone are designed to resemble natural stone. 877-424-4442. www.unitedstoneveneer.com.
Eldorado Stone. RomaBrick–shown here in Bracciano, a blend of reds and burnt blacks–features a longer profile and wider proportions intended to evoke ancient Rome, says the manufacturer. Irregular in shape, the manufactured stone can vary from 9 inches to 10-1/4 inches in length and 1-1/2 inches to 2 inches in height. 800-925-1491. www.eldoradostone.com.
Crown Hill Stone. Alleghany Stack manufactured stone, shown in Chatauqua Blush, was developed to create the look of a dry lay–meaning no visible mortar. Alleghany Stack can be blended with a variety of the company's other products to create a unique look. The product is colorfast, weatherproof, and durable and no heavy foundations or footings are required for installation, the company says. 800-295-1120. www.crownhill.com.
Trilite Stone. Splitrock, shown in Lake Country, combines the rough, textured stone of the Splitface style with the smooth, rounder edges of the company's River Rock product. The product is a handcrafted lightweight stone veneer, made from individually selected stones using a unique blend of portland cement with natural aggregates and pigments, the company says. 888-786-6626. www.trilitestone.com.