Materials | Manufactured Stone
By Jim Cooper,
National Director for Artisan Masonry Stone Veneers
All photos courtesy of Echelon Masonry.
For light commercial building such as hospitals, retail buildings and senior living facilities, manufactured stone veneers are offering cost-savings, speed of installation and great looks. Rather than having a painted block building, communities are demanding—often through government-approved ordinances—that buildings blend in to local surroundings and have better aesthetics. That is where stone veneer comes into play and for developers and builders, where new technology in masonry can help achieve this at a better cost and with higher performance. The choices in manufactured stone veneers have expanded, which can lend both performance and customized aesthetic advantages. And, the manufacturing processes to achieve certain performance characteristics have greatly advanced.
Technology advances and performance
Traditionally, both lightweight and full-depth stone veneers have been manufactured through a wet-cast process using latex molds for lightweight veneers. In wet-casting, natural stones are arranged in a pattern with latex sprayed on the stones to create a mold. When it came time to cast the veneers, the molds were hand-painted with the colorant specified to resemble a particular variety of stone. The resulting veneers were only colorized on the outermost layer. If the veneers chipped accidentally, or purposely cut during installation, the non-colored aggregate on the interior was exposed. In addition, special corner and trim pieces are needed to obtain finished, real-stone looks without sacrificing color consistency.
By comparison, a new mold technology known as the dry-cast production method offers significantly longer life spans and results in a dimensionally stable product. The proprietary process is similar to paver technology, and begins by scanning natural stone and turning those scans into patented mold technology. A low-moisture mixture of fine aggregates, cement, admixture and integrated colorant are densely compacted into the molds, then stripped from them and cured in a high‐humidity environment. It also contains water repellents in the mix and uses 40 percent less water than wet-cast in the process. The resulting veneers contain only 6-percent moisture, whereas wet-cast has 33 percent. So the dry-cast veneers are more resistant to de-icing salts that are sprayed on sidewalks, while wet-cast stone tends to soak that in and disintegrate.
Dry-cast veneers are perfect for ashlar, stacked, and square applications that require a stacked look while resisting freeze/thaw, water absorption and fading, typically at significantly less cost than wet-cast veneers. It is well suited for retail and light commercial construction for speed of installation and versatility.
In addition, the lightweight and full-depth veneers manufactured through dry-casting offer a PSI strength that is two to three times stronger than traditional veneer and have color integrated throughout the unit, which eliminates the need for special corner pieces and reduces waste caused by chipping. The dry-cast veneer process has the ability to create colors, textures, widths and profile sizes similar to natural stone, which also allows the two materials to be used together. But when might you use a lightweight or thinner profile vs. a full-depth profile?
Full-depth vs. lightweight veneers
Choosing full-depth vs. lightweight veneers can vary by personal taste and comfort level, and largely depends on the application. Wall height can be a factor as well. It is rare, but manufactured lightweight veneers, which use adhered masonry, may have less of a comfort level when installed on a high wall in the rare case one were to come loose. In that application, the builder or retailer may prefer to spend more on a cavity wall to accommodate a full-depth veneer, which is typically 3 5/8 inches. Stone veneers are easy to match to natural stone, which are cut to the same width as a full-depth or thin veneer. Full-depth veneers have a bed depth like a brick, so you can mix those as well. Many customers will choose lightweight veneers as an economical facade, such around a retail building or a senior living facility, which is a huge opportunity, as mixed material looks of siding, stucco, and stone foundation facades and accents are trending.
Another advantage for dressing up a light commercial building is to blend manufactured stone and brick. A sill is still required to separate them, but the bed depth accommodates a set-in product like full-depth veneer, although the cost is higher than an adhered application.
Manufactured stone veneer color choices
When measuring wet- vs. dry-cast advantages, consider that dry-cast colors can be customized onsite, especially for an architecturally distinctive structure more so than retail. A recent largescale, 40,000-square-foot museum did just that to match colors in the natural environment, and then saved significant costs by blending manufactured full-depth veneers with locally sourced stone. The colors of nature were easily blended onsite in a way that the architect desired.
For national retailers, manufactured stone veneers add speed and economy to the building process, but also can dress up buildings more effectively than painted block with little effort. For example, a popular trend for retail is to do integral colors of split-face block combined with Quik Brik, a manufactured structural concrete brick that can provide the look of brick but can cost half of what a cavity wall required for brick would cost. As more aesthetics in communities come into play, look for more retail buildings to adopt the mixed material veneer look, which will likely be manufactured thin or full-depth based on cost. Smaller retailers, condos, hotels, and senior living facilities are going in this direction to blend in nicely with the community and meet local ordinances.
The exploding trend of senior living facilities due to the aging baby boomer population are a prime example of making a residence building feel like home, both on the exterior and interior. These structures are typically 1 – 5 stories, with a band of stone veneer around the lower level and stucco or siding on the upper wall. Manufactured lightweight veneers can provide the beautiful textures and colors, but with much higher performance, low moisture and low cost.
For light commercial application exteriors, it pays to look at the overall project—what are the aesthetic needs, moisture considerations, the de-icing chemicals used and will the project require a cavity wall or more decorative adhered aesthetic look. For long-term performance, dry-cast manufactured stone veneers provide easy installation, fewer headaches, significant cost savings and a fast and easy installation for any light commercial project.
Jim Cooper is the National Director for Artisan Masonry Stone Veneers—part of the Echelon Masonry portfolio of products from Oldcastle Architectural. Previous to his role with Oldcastle, Cooper worked for Cultured Stone as a national sales manager. Visit www.EchelonMasonry.com.