LEVELROCK RH

LEVELROCK™ Brand Floor Underlayment RH (Radiant Heat) 

Premium poured gypsum flooring underlayment products – Fast application, fast setting allows for return of light traffic within hours – Specially formulated for radiant flooring – UL designs available up to 2-hour fire rating – Smooth crack-resistant surface – Helps maximize sound isolation between floors/units – Applied by USG licensed contractors System Description LEVELROCK™ Brand Floor Underlayment RH (Radiant Heat) is a fast-applying gypsum cement designed by USG for use in both residential and commercial construction. LEVELROCK Brand Floor Underlayment RH (Radiant Heat) is specifically formulated for electrical and hot water radiant heat floor installations. It is formulated to provide compressive strengths up to 3200 psi at a 3/4-inch minimum thickness up to 3-inch maximum thickness. The tough compressive and surface strengths of LEVELROCK Brand Floor Underlayment RH (Radiant Heat) allow for long-term resistance to trade activity typical of single-family home and light commercial construction. It accepts virtually all types of floor coverings such as ceramic tile, carpeting, and wood. The non-shrinking nature of LEVELROCK Brand Floor Underlayment RH (Radiant Heat) locks tubing in place, preventing noise and tube chafing, and its special formulation prevents the high temperature associated with radiant heat floors from breaking down the floor matrix. Product Description USG poured gypsum underlayment products are mixed with sand and water to yield a lightweight slurry. Most radiant heat jobs will be poured at 1-1/2 inch thickness to cover the pipes. A 1-1/2-inch thick gypsum underlayment weighs approximately 14.4 pounds per square foot and has a density of only 115 pounds per cubic foot. System Benefits USG poured gypsum floor underlayment systems provide an economical way to achieve lightweight, fire-resistant, sound-rated floors in residential and light commercial construction. Typical applications are less labor intensive than many other types of construction and provide high fire ratings characteristic of gypsum systems. Higher compressive strengths minimize damage to floors from trades. Physical Properties Typical Compressive Strength (aggregated) ASTM C472 Density (aggregated) 2500-3200 psi 115 lb./cu.ft. Limitations USG poured gypsum floor underlayment systems should not: 1. Be used as a wearing surface. 2. Be installed where continuous exposure to moisture is a possibility (for instance, exterior balconies or shower rooms). 3. Be installed in below-grade applications. 4. Be used with radiant heat systems having prolonged operation temperatures exceeding 150 °F. Installation During the entire installation process, the building must be enclosed and temperature maintained at 50 °F minimum until permanent heating is available. Adequate ventilation must be provided to ensure uniform drying of the installed gypsum floor underlayment, which typically occurs within 10 to 14 days at 1-1/2-inch thickness. Limit design of the subfloor and framing to a minimum of L/360 to prevent undue stress from occurring in the floor fill material, as this stress may produce cracks. Over plywood subfloors, tongue-and-groove edgesupported type plywood is recommended for meeting this deflection criterion. The application of LEVELROCK Brand Primer to the subfloor is necessary to provide maximum bond between the underlayment and the subfloor. Concrete slabs that are receiving gypsum underlayment systems must be properly cured (generally for a minimum of 28 days) prior to the underlayment installation. Concrete slabs should be properly treated with LEVELROCK Brand Primer according to manufacturer’s recommendations.

UL Designs G230, G516, J917, J919, J920, J924, J927, J931, J957, J966, J991, J994, K906, L206, L501, L505, L511, L512, L513, L514, L518, L521, L524, L525, L528, L529, L530, L534, L535, L536, L537, L541, L544. Model Building Code Approvals International Conference of Building Officials (ICBO) Report No. ER-5885 Building Officials and Code Administrators International, Inc. (BOCA) Research Report No. 2152 Southern Building Code Congress International (SBCI) Evaluation Report No. 2114 Specifications Note to Architect These are specifications for the installation of LEVELROCK Brand Floor Underlayment RH (Radiant Heat) covering normal project requirements. For additional data regarding special conditions and applications, please contact your local USG representative.