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USG Levelrock® Brand 3500 floor underlayment is a high-quality, versatile engineered cementitious underlayment for indoor use in light-commercial and renovation construction. It can be easily applied over wood and concrete subfloors at a thickness of up to 3 in. Its high compressive strengths at low thicknesses provide superior underlayment performance for higher-traffic areas and minimize floor damage from trades. High production rates, lightweight with high compressive strength and fire resistance make USG Levelrock® Brand 3500 floor underlayments ideal alternatives to lightweight concrete floor applications. USG Levelrock® Brand 3500 FR floor underlayment is a high-quality, versatile engineered cementitious underlayment reinforced with fibers that improve impact strength. A cost-effective solution for indoor use in light-commercial and renovation construction, USG Levelrock® Brand 3500 FR engineered cementitious underlayment can be easily applied over wood and concrete subfloors at a thickness of up to 3 in., and can be applied to concrete surfaces without mechanical profiling. High compressive strengths at low thicknesses provide superior underlayment performance for higher-traffic areas and minimize floor damage from trades. High production rates, lightweight with high compressive strength and fire resistance make USG Levelrock® Brand 3500 FR floor underlayment an ideal alternative to lightweight concrete floor applications. Levelrock® Brand 3500 pre-sanded floor underlayment is a pre-sanded version of the 3500 product. It allows for ease in application at the jobsite. USG Levelrock® Brand 3500, 3500 FR and 3500 Pre-Sanded Floor Underlayment products may assist in obtaining LEED credits 5.1 and 5.2.