Steven Fechino
Today many mason contractors not only lay brick and block, many are now installing thin veneers as a way to better control schedules and diversify their ability to pick up additional work on projects that require additional skills. Sometimes when thin veneers are involved, it seems like a new thing, but they have been around for many years.
Not every project will go well (my first one was a disaster) and many projects will require you to answer some tough questions. The following is more for reference than reading. I broke down what each association governs and the important ASTM’s (American Society for Testing and Materials) that may answer that question on thin veneers when it arises.
The main associations
- Masonry Veneer Manufacturers Association (MVMA)-Providing guidance in the application and design of adhered manufactured stone veneers. Manual published for use is an Installation guide and detailing options for compliance with ASTM C 1780, 4th edition, 2nd printing
- National Concrete Masonry Association (NCMA) represents the concrete manufacturers and distributors
- International Code Council (ICC-ES) provides acceptance criteria for industry products through evaluation and testing.
- International Building Code (IBC) is the governing code that recognizes the minimum requirements of a building product. The IBC does not govern single-family townhomes up to three stories, single-family or duplex construction
ASTM
The ASTM is a very detailed group of standards that many contractors do not have direct access to unless they are a member of a committee. The following list is the standard number and title along with a quick description of what the standard represents. If the standard looks interesting, you can search it online and get a full description of the standard and the opportunity to purchase the standard. Standards are not typically shared by industry professionals.
- ASTM C1063 Standard Specification for Installation of Lathing and Furring to Receive Interior and Exterior Portland Cement-Based Plaster-This standard is broad to the industry referring to suspended ceilings, hangers, and runners attachments, nails, screws and weep screed placements. It is especially useful in the dos and don’ts of lath placement and attachments.
- ASTM C1384 Standard Specification for Installation of Lathing and Furring to Receive Interior and Exterior Portland Cement-Based Plaster- This standard specification discusses the additives or admixtures that are combined with conventional mortar to enhance one or more properties. The properties that are affected by the admixtures range from bond strength, workability, and rate of water retention and absorption to list the few that directly relate to adhered masonry. Most admixtures today are pre-blended at the manufacturing plant to ensure consistency in all aspects of performance.
- ASTM C1670 Standard Specification for Installation of Lathing and Furring to Receive Interior and Exterior Portland Cement-Based Plaster- This standard is important for the consistency and quality of manufacturing the cementitious stone veneer units. This specification addresses the mix matrixes, tolerances, durability, finishes, and admixtures that make up the stone masonry veneer units.
- ASTM C270 Standard Specification for Mortar for Unit Masonry- This standard specification is the basis for determining the properties and testing of your mortar used in reinforced and non-reinforced construction of unit masonry. This standard breaks down the material into two classifications, proportional specification, and property specifications. Mortars that fit in this standard would be considered a conventional mortar.
- ASTM C847 Standard Specification for Metal Lath- This standard specification is for the manufacturing of lath when used with Portland cement and plaster adhered masonry veneers. The standard discusses the different types of laths available, both with and without backing materials directly attached to the lath.
- ASTM C1059/C1059M Standard Specification for Latex Agents for Bonding Fresh To Hardened Concrete- The Standard discusses the application of latex bonding agents for applications far beyond adhered masonry veneers, however, this outlines the application by brush, broom, and spray when placing new concrete against hardened concrete such as the topcoat to base coat joint. This is for the external use of latex modifiers where admixtures will be outlined in C1384
- ASTM 1714/C1714M Standard Specification for Installation of Lathing and Furring to Receive Interior and Exterior Portland Cement-Based Plaster- This addresses the rigid measures used to maintain consistent ratios used in mortars that fall into the category of ASTM C270. Mortars discussed in this standard are pre-blended masonry mortars at a manufacturing plant as a method of maintaining quality and consistent performance in the test results
- ASTM C1780 Revision of C1780 – 13 Standard Practice for Installation Methods for Adhered Manufactured Stone Masonry Veneer- This is a standard that has equal value to the manufacturers, designers, and contractors that work in adhered masonry veneers. This specification covers a list of definitions that pertain to the installation of the veneers, placements of the substrate backer board and preparation, different types of lath, installation of the cementitious base
Hopefully, you will never be in a position to answer a question by doing this level of research, but now you can file this away and know you have a quick cheat sheet if you ever need it.