Engineered and manufactured building products may look like traditional natural building materials, but that doesn’t mean you should treat them like the materials they are meant to look like.
Manufactured Stone Veneer (MSV) is a porous, lightweight concrete mixture that has the appearance of natural stone. It is readily available in many different textures, shapes, and colors, and, when properly specified, detailed, and installed, it can be a viable alternative to using natural stone. MSV has the benefit of being lighter, easier to cut, and easier to handle compared to natural stone, potentially making it a more cost-efficient exterior cladding system than natural stone.
But it is not a stone product, and it shouldn’t be treated like a natural stone product.
If you have ever had manufactured stone veneer masonry installed on the exterior of a building, and the installer didn’t maintain the proper clearance to grade, or worse, ran it below grade, then chances are it was installed incorrectly.
That’s not my opinion, that’s what the MVMA suggests.
The MVMA, the Manufactured Veneer Masonry Association, is a trade association that represents the major manufacturers of manufactured stone veneer (MSV) products.
It may not entirely be your fault. And you certainly are not alone. In fact, masonry stone veneer is only one manufactured product made to resemble a traditional building material that cannot be treated like its natural analog, but that’s the subject for another article. Another is cement board siding, but that’s the subject of another article.
Interestingly, many of the photographs of completed projects that manufacturers use on their websites and in their published marketing materials show their products that appear to be installed contrary to their own recommendations.
A Beginner’s Guide
Cultured Stone is one of the largest brands of MSV products. In fact, it’s name has become synonymous with MSV to most people, like Band-Aid is to adhesive bandage or Xerox is to photocopy. In my opinion, they do the best job of explaining exactly how their products should, and shouldn’t, be used.
In Cultured Stone’s, A Beginner’s Guide to Manufactured Stone Veneer, the manufacturer suggests that it’s “…important to consider every last detail during the design phase…” And to that end, they have“…put together this guide to help you and your clients better understand manufactured stone veneer…”.
Your architect and installer would do well to heed their advice.
The MVMA’s guide specifications state that you must install MSV in accordance with manufacturer’s instructions and in accordance with MVMA Installation Guide for Adhered Manufactured Stone Veneer, ASTM C 1780, and applicable Codes.” Putting it more simply, to do this, you must:
While the aesthetic design possibilities and potential cost savings of manufactured stone veneer materials over natural stone products is evident, the architect and installer need to consider the final as-built condition in order to reap those benefits without compromising durability, voiding the warranty, or risking exposure to liability.
The architect / installer must carefully consider and properly detail the product where MSV meets grade, and it must be properly installed.
One design strategy is to use a different material to a height of at least 4 inches above finished grade. This presents a challenge on sloping sites as building products cannot readily be installed at an angle without careful detailing and a lot of cutting, increasing labor costs and material waste.
Also, it is highly unlikely that the installer will know exactly where the landscaper will set the final grade after the installer’s work on the project is completed, leaving it to the general contractor to coordinate the construction in place with the approved contract documents prepared by the architect.
A better strategy is to create a “water table” of a more durable material at a height in excess of the required 4-inch clearance, stepping down with the sloping grade, and accounting for some field coordination between the MSV installer and the landscape contractor.
The strategy used to handle the limitations inherent in this product is at the discretion of the architect. In any case, this product must be detailed and clearly dimensioned to indicate the architect’s design intent. Standard details provided by the manufacturer may need to be modified to suit site conditions and achieve the desired aesthetic effect the architect intended.
During construction, it would be wise for the architect to assure that the MSV is installed in accordance with the approved construction documents, the applicable building codes, and the manufacturer’s latest installation instructions; another strong argument for always providing Construction Phase Services on every project.
As with any building product, architects, installers, and building owners are advised to take the time to research, read, and fully understand the manufacturer’s literature, and then use own their professional judgment when using, designing, and installing these products. Failure to understand the implications and limitations of these products may void the product warranty, produce costly maintenance issues for the owner, and create potential liability for the architect and installer.
IF YOU HAVE ANY QUESTIONS, CALL ME. THE FIRST CALL IS FREE.
DRAWINGS WILL COST A LITTLE MORE.
David Del Vecchio, AIA, is a licensed architect in NJ, NY, CT, PA, MA, and FL; a Certified Interior Designer; a LEEDap Accredited Professional; an RCS Building Inspector; and an NCARB Certificate holder.
His practice includes custom residential design, professional office design, and commercial building design for busy, discerning clients who know what they want, have the financial means what they want, and want it done right the first time.
He also helps his clients (insurance carriers, attorneys, architects, interior designers, contractors, home owners, commercial landlords, and municipalities) resolve complicated construction claims.
“If it’s important to you, it’s a priority for me.”