The American Society of Testing Methods (ASTM) International Committee F06 on Resilient Floor Coverings has approved a new standard, ASTM F2419; Standard Practice for Installation of Thick Poured Gypsum Concrete Underlayments and Preparation of the Surface to Receive Resilient Flooring. This standard was adopted to ensure that thick poured gypsum concrete underlayments are an acceptable surface to receive resilient floor coverings. The standard also promotes a better understanding of gypsum concrete underlayments, which are widely used in structures throughout North America for fire resistance, sound control and to provide a smooth, flat surface for finished floor coverings.
Prior to its adoption, no standard for the installation of gypsum concrete underlayments existed even though millions of square feet are installed annually. ASTM Committee F06 accepted the challenge of developing an industry standard.
The Task Group responsible for creating the much-needed standardization was F06.40.04 Thick Poured Gypsum Concrete Underlayments, under the jurisdiction of F06.40 Practices, which is part of F06, Resilient Floor Coverings. ASTM Technical Committees are comprised of highly qualified, industry specific professionals from around the globe. When a standard is written and finally approved, it is the result of many months or years of submissions, data analysis, committee debate and ballots by experts in the field.
This was precisely the course taken in the creation of ASTM F2419. The Standard was adopted by a committee of resilient flooring manufacturers, adhesive manufacturers, gypsum concrete underlayment manufacturers, moisture meter manufacturers, consultants to the floor covering industry, testing labs and other industry professionals. ASTM F2419 is a milestone in the path embarked upon by Committee F06 to ensure consistent resilient floor covering applications, specifically addressing the concerns of the resilient floor covering industry and manufacturers to establish approved guidelines for gypsum concrete underlayments.
- Minimum compressive strength of 2000psi (13.8 MPa) for use over wood subfloors per ASTM C472
- Minimum compressive strength of 3000psi (20.7 MPa) for use over concrete subfloors per ASTM C472
- 3/4" (19mm) minimum thickness over wood subfloors
- 1/2" (13mm) minimum thickness over cast in place concrete
- 1"(25mm) minimum thickness over sound mat
- Maximum subfloor deflection of L/360
- Continuous ventilation required until the underlayment is dry
- Moisture testing prior to installation of resilient floor coverings
- Priming in accordance with the recommendations of the resilient floor covering manufacturer
Additional guidelines within the Standard define proper subfloor preparation, requirements for a minimum ambient temperature of 50°F (10°C) which must be maintained before, during and after installation and the provision of adequate ventilation necessary to assure proper drying of the gypsum concrete underlayment. Installations should be completed only by an applicator recommended by the gypsum concrete manufacturer. Since satisfactory performance of the finished flooring depends, in part, on the condition of the thick poured gypsum concrete underlayment, it should be protected from heavy traffic via wheeled or concentrated loads by using temporary walking boards until the underlayment is dry.
The practice does not address the structural adequacy of the wood panel or concrete subfloor, nor does it supersede in any manner the thick poured gypsum concrete underlayment manufacturer's, adhesive manufacturer's or resilient flooring manufacturer's written instructions. Consultation with each individual manufacturer for specific recommendations is advised.
Suppliers of gypsum concrete underlayments, such as Hacker Industries, Inc., support the new standard and believe by providing definitive guidelines for product quality that the understanding between trades will improve. To give an example of this support for the standard, Hacker Industries, Inc.'s TopCoat™êSP contains a built-in color identifier to assure compliance with ASTM Standard F2419's recommendation of a topcoat/sealer. TopCoat™ SP is applied over any floor underlayment to enhance and strengthen the bond between the gypsum floor underlayment and floor covering adhesives.
The work of the Task Group continues today with the development of a standard for the Installation of Self-Leveling Underlayments. All interested parties should attend the next meeting in November of 2006 in Cancun, Mexico.
For referenced ASTM Standards, please visitwww.astm.orgor call (610) 832-9585. The technical contact is Kerry Hacker at Hacker Industries, Inc. Please call (800) 642-3455 or contact via e-mail firstname.lastname@example.org.