CoatingsPro Magazine

JUL 2017

CoatingsPro offers an in-depth look at coatings based on case studies, successful business operation, new products, industry news, and the safe and profitable use of coatings and equipment.

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Page 34 of 68

34 JULY 2017 COATINGSPROMAG.COM Science Behind It Why the Need for Moisture Mitigation? By Ben Grier, Global Product Manager, and Chris Brana, Product Manager, at LATICRETE A ddressing moisture emissions in substrates, such as concrete slabs, should be a key component of proper surface preparation, included with ensur- ing that the slab is clean and meets International Concrete Repair Institute's (ICRI) Concrete Surface Profiles (CSP). It is imperative early on to address any moisture concerns in the substrate before applying any self-leveling underlayments or finished flooring installations. If not addressed, this could result in additional costs and repair time for flooring installation failures in the long run. A s an industr y, we are being proactive in dea ling w ith moisture mitigation and addressing the increase of moisture-sensitive f loor ing and applications. One such solution may be a moisture bar r ier, so what does that mean? What Are Moisture Vapor Barriers, and What Do They Do? Moist u re vapor ba r r iers a re u sed on conc rete to help m it igate moist u re em issions a nd proh ibit t he moist u re i n t he sl ab a nd g rou nd f rom com i ng up i nto t he coat i ng s ystem. Moist u re m ig rat i ng f rom below a water proof s ystem cou ld c au se bl ister i ng a nd ot her prem at u re fa i lu res. T hese moist u re vapor ba r r ier produc ts shou ld a l so comply w it h i ndu st r y st a nd a rd s, for e x a mple t he y shou ld meet or e xceed A S T M F3010: Standard Practice for Two-Component Resin Based Membrane-Forming Moisture Mitigation Systems for Use Under Resilient Floor Coverings. Idea l ly t he y shou ld be fa st- c u re, genera l ly less t h a n 24 hou rs, h ave low vol at i le orga n ic compou nd ( VOC) content, a nd h ave low odor. T he y t y pic a l ly a re epox y- bor ne a nd c a n be si ng le - or t wo - component s ystems. On projects such as the Tex as Motor Speedway, a vapor bar r ier w i l l of ten be used. Dif ferent mater ia ls can be found in both the g round and concrete. T hese can be par tic les, chemica ls, ca lcium, and limes. T hese mater i- a ls leaching can be obser ved on some concrete retaining wa l ls where a white substance covers cer tain areas. T here, water w ith ca lcium chlor ide (or sa lt) mig rated through the concrete — the water evaporated and lef t behind the sa lt deposits. T his is simi lar to how it wou ld work on a slab. W hen elevated moisture in concrete mi xes w ith one or severa l of the mater ia ls, it can create a ver y cor rosive solution that w i l l attack the bond point for whatever w i l l be on the sur face. In this case, that bond point is the f loor coating system. What Is DRYTEK Moisture Vapor Barrier, and How Does It Work? DRY TEK Moisture Vapor Barrier is an example of one of these moisture mitigation systems. It is a chemically enhanced epoxy that resists chemicals that could potentially lead to a future failure. It may be used as an underlayment for resinous flooring as well as other types of commercial floor- ing systems. DRY TEK Moisture Vapor Barrier is a single-coat, two-component, 100 percent solids, low odor, liquid-applied, two-part epoxy coating specifically designed for controlling the moisture vapor emission rate from new or existing concrete slabs prior to installing underlayments, decorative toppings, and most resinous coatings. DRY TEK Moisture Vapor Barrier exceeds ASTM F3010 standard with a perm rating of 0.052 grains per hour per square foot per inch of mercury Hg (3 ng/hr. • m 2 • Pa) at only a 12-mil (304.8 microns) thickness. It ensures protection of moisture/pH sensitive floor coverings. It reduces moisture vapor emissions rates (MVERs) from ≤25 to below 3 pounds per 1,000 square feet per 24 hours (170 μg/(s • m 2 )). You can use it on concrete up to 100 percent RH/14 pH. Per ASTM F3010, a concrete slab coated with DRY TEK Moisture Vapor Barrier must have a tensile pull-off strength of 200 psi (1.4 MPa) or greater when tested in accordance with ASTM C1583: Standard Test Method for Tensile Strength of Concrete Surfaces and the Bond Strength or Tensile Strength of Concrete Repair and Overlay Materials by Direct Tension (Pull-off Method). Conclusion Moisture mitigation is a key component to properly prepar- ing the concrete surface, and it should not be ignored. Concrete lives and breathes; it acts as a sponge to absorb moisture from a wet area and disperses it into a dr y area, so if the ground is wet and the slab is coated, it w ill w ick upward. A moisture barrier w ill help you be proactive in avoiding premature coating failures on your f loor. CP

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