By Louis Iannaco
NEW YORK—The Greater New York Floor Coverers Industry Promotional Fund presented “Understanding and Diagnosing Concrete Floor Moisture Conditions to Prevent Floor Covering Failures” on Oct. 18.
The educational discussion was designed to bring architects, designers and contractors together and onto the same page regarding the issue of concrete moisture.
The well-attended seminar filled its scheduled two-hour time slot but could have gone much longer as the meeting was full of information regarding multiple aspects of concrete moisture, including terminology, industry standards and third-party testing. Questions such as, “Where does moisture come from?” and “Moisture Testing: Why, How and Who?” were also covered during a comprehensive PowerPoint presentation given by panelist and concrete moisture expert Christopher Capobianco, sales and technical specialist for Spartan Surfaces.
The event’s esteemed participants also included Al Baer, president of Baer’s Rug & Linoleum; Lee Eliseian, president of Independent Floor Testing and Inspection (IFTI), and industry concrete moisture guru Larry Press, director of Flooring for Helmitin Adhesives, all of whom answered questions posed by various sources through Capobianco and attendees during a Q&A session, as no stone or concrete slab was left unturned.
When it came to the subject of terminology, a main point brought forth was the confusion between cement and concrete, as well as the differences in curing and drying. “This is arguably one of the key areas where things go wrong on new construction sites with regard to concrete,” Capobianco said, “because an assumption is made that when concrete is cured it’s ready for a floor.”
Curing and drying are two completely different things, he explained. “Curing is a chemical reaction that binds all of the ingredients together, while drying is what happens after that. They don’t happen at the same time. The standard we all hear about—28-day curing time—doesn’t mean you’re putting a floor down on day 30.”
Methods of curing as well as the differences of on-grade and below-grade were brought up on how concrete moisture relates to each. In discussing where moisture comes from, factors such as liquid water in the mix, water vapor from the ground and external sources like drainage problems, slab coming into contact with wet soil from sprinklers and landscaping being too close to the building were also covered.
Capobianco noted the No. 1 aspect coming out of the meeting for him was how “events like this stress the importance of communication between the flooring and construction trades, meaning architects, general contractors, flooring contractors, flooring manufacturers and adhesive producers. The more we can communicate with each other, the more likely we will have specifications written that avoid some of these problems we’re having in the field.”
In how best to prevent the problems from concrete moisture, one of the main points he made in his presentation noted a guideline from ASTM F710: “All concrete slabs shall be tested for moisture regardless of age or grade level.” Afterwards, he reiterated that point, stressing “the importance of testing absolutely every concrete slab there is. That one line from ASTM F710 says it all.”
IFTI’s Eliseian discussed, among other things, the differences between the calcium chloride and relative humidity tests, noting one of the ways the seminar was effective for contractors was showing how “they can position themselves out of the liability loop when it comes to concrete slab moisture issues. If they can get away from that where they are just doing the installation, I believe it would make for a much healthier environment.”
As Press noted, concrete moisture is not a new phenomenon. “This has been going on since the ’30s, but the construction habits introduced regarding speed, money, HVAC not being on, etc., and with all the pressure on the general contractor to get it done under any circumstances, no one wants to pay for it. And then after the fact, it costs more. If they would set aside money in the front and say, ‘OK, we’re going to open up the slabs, we’re going to provide heating and ventilation [as well as other preventative measures],’ there would be no issues.”
Leslie Levy, a freelance draftswoman specializing in AutoCad and design development for architects, interior designers and contractors, agreed with Press, saying new construction practices and changing materials have combined to increase floor covering failures due to moisture in concrete, and existing slabs can conceal problematic moisture conditions.
“This event brought together key stakeholders—manufacturers, installers, designers, inspectors—to share their expertise, perspectives and concerns, and learn from one another what each can do to prevent or minimize failures,” she explained. “The value of this is obvious, since it is far less expensive to approach a potential problem proactively, and even better to avoid creating one.”
For Levy, the seminar served “to call my attention to the delicate chemistry that plays between concrete slabs and their coverings. The next time I’m called upon to draw another commercial floor finish plan or the design for a residential room below grade, I’ll be certain to point out the importance of assessing slab conditions. And for every concrete slab I draw, I’ll ask what finish materials are to cover it, and when.”
Martin Murdoch, executive vice president of contractor M.E. Sabosik Associates, said, “The ability to talk with the A&D community to explain the problems on our side” was key for him. “There is a lot of disconnect between the two. And by bringing the A&D community in to understand those differences gives us the ability to work some of these problems out.”
According to architect Ernest Naples, while the seminar was titled, “Understanding and Diagnosing Concrete Floor Moisture Conditions to Prevent Floor Covering Failures,” he came away with much more, including learning about the issues that can contribute to the success or failure of flooring over concrete, such as the “moisture content of a concrete floor system must be allowed to dissipate to acceptable levels before flooring is applied, and slabs on or below grade must be installed over a vapor barrier.”
He also noted how improper handling and storage of floor covering materials from manufacturer to job site, as well as temperature and humidity prior to and during installation, can result in floor covering failures. And, much like Murdoch and Capobianco, Naples believes “communication among owners, the design team, suppliers, the contractor and subcontractors—including pre-construction meetings—is critical [and] all involved fully understand the issues that will insure a successful floor covering installation, and will act upon them.”