SITE CONDITION
• Building must be fully enclosed including doors, windows and roof.
• Interior ambient temperature must be 50ºF at least one day before installation and maintained at “a minimum of” 50ºF temperature for a minimum of 5-7 days after installation or until dry.
• Adequate ventilation must be maintained until the moisture in the gypsum has been allowed to evaporate. This requirement is typically a minimum of 5 to 7 days, but may be longer depending on thickness of underlayment, humidity and conditions in the local environment.
• Subfloor must be a minimum of L/360, broom swept clean with all excess wallboard mud removed and all holes patched.
• Wood construction must be with tongue and groove subfloor (OSB or plywood).
• For installation on concrete substrates the subfloor must be fully cured (minimum 28 days). Moisture tests should be performed to assure proper hydration under ASTM F1869 to assure MVE level is less than 3.0 lb. per 1000 square feet.
• For below grade applications or over a crawl space, vapor barriers must be applied.
SUBFLOOR PREPARATION
Subfloor must be properly primed. Use GSL PRIMER on all surfaces. Approved priming methods include: roller, soft bristle broom, brush or spray. All supporting surfaces shall be structurally sound, solid, free of movement and well bonded. They shall be dry, free of dust, oil, grease, tar or other contaminants that may act as a bond breaker. Deflection cannot exceed L/360.
Priming
Dilute GSL Primer before application. Dilute 1 part GSL Primer concentrate to 4 parts potable water (1:4). Using a long handle roller, soft bristle broom, brush or sprayer, apply GSL Primer at a coverage rate of 270-320 sq. ft. per gallon of primer solution. Coverage rate varies depending upon surface porosity. Ensure a complete and uniform coverage. Allow to become very tacky or dry (about 1 hour).
Mixing
Follow DEPENDABLE, LLC guidelines and specifications. GSL is only to be installed by trained contractors approved by Dependable, LLC.
Compressive Strength
3200 – 4500 psi
Substrate
Plywood, OSB, concrete, precast concrete and approved acoustical treatment are acceptable. Wood substrate must be of proper thickness, tongue and groove construction and properly fastened. Concrete should be clean, dry and free of obvious structural problems. All substrates must be properly sealed and primed before the GSL floor underlayment is applied.
Storage
Material should be kept in a dry area. Avoid ambient temperature below 50°F and above 110°F for prolonged periods. Shelf-life of six months.
APPLICATION
• Multiple lifts: Multiple lifts may not require a primer with GSL. Second lift can be accomplished upon an initial set that can handle the load of the hose operator and finisher.
NOTE: Temperature and humidity levels affect the drying characteristics of GSL. However, unlike Portland cement materials, GSL may be force dried with the use of heat or fans once set.
LIMITATIONS / PRECAUTIONS
• DO NOT USE IN EXTERIOR APPLICATIONS. For Interior use only
• GSL is NOT a wear surface.
• DO NOT INSTALL WITHOUT TONGUE AND GROOVE SUBFLOOR unless utilizing back bracing or filling all joints.
• CHECK JOIST DEFLECTION and assure performance greater than L/360
• ASSURE BUILDING IS COMPLETELY INCLOSED including doors, windows and roof.
• INSTALLATION TEMPERATURE MUST BE 50ºF and rising.
• PROVIDE ADEQUATE VENTILATION after placement of GSL until dry.
DO NOT USE…
• Where hydrostatic pressure (water) is present or moisture emissions exceeds level permitted for installed floor covering.
• Where surface or ambient temperature falls to or below 50°F 72 hours before or after installation.
• As a trowelled patch or at less than natural minimum flow thickness.
• Exterior, exposed applications or as a wear surface.
