Allied Custom Gypsum 
AccuCrete® Brand Underlayment products are formulated to be used in a variety of floor underlayment applications, and are set apart from the competition by providing superior surface quality for adhered floor goods. All AccuCrete® Brand Underlayments are now available in Green Versions certified by UL Environment®. Allow us to assist you with your upcoming project.
Atlas Tech Products - CA, AZ, NV, NM, UT & CO
Atlas Tech Products provides self-leveling and trowelable floor underlayments to provide a level hard surface prior to installation of tile, wood, carpet and other flooring materials. Tech-Level Premier is self-leveling and can accept coverings after 24 hours. Feather Coat is a fast-drying trowelable skim coat that can accept coverings after 20 minutes.
Duraamen Engineered Products
Päram 5500 is calcium aluminate cement based self leveling concrete overlay for fast rack resurfacing and leveling existing substrates like wood/plywood, ceramic tile, VCT, etc. It can be applied from 1/8in to 1.5in in one pass. It can accept ceramic tiles and natural stone within 3-4 hours after its installation.
The Euclid Chemical Company
The Euclid Chemical Company designs and manufactures concrete and masonry admixtures, curing and sealing compounds, industrial coatings, structural grouts, epoxy adhesives, floor hardeners and toppings along with a comprehensive selection of restoration/repair materials. Marketed under the EUCO, EUCON, TAMMS, DURAL and SPEEDCRETE brands, Euclid Chemical offers a full line of new construction and repair materials.
Hacker Industries 
Hacker Industries, Inc. offers a wide variety of FIRM-FILL brand gypsum concrete underlayments and acoustical control products for use over wood, steel deck, or concrete. With the proven performance of 2 billion square feet installed across North America, our products create a durable, sound-rated and fire-resistance surface for finished floor coverings.
Keene Building Products
Keene Building Products manufacturers 3-dimensional noise control products for multi-family apartments and condominiums to stop impact and airborne noise. Quiet Qurl® products are available with traditional moisture control (MC) fabric, MT (Muffling technology enhancement) and RF (reinforced fiberglass). These range in thickness from 0.125 inch-0.75 inch with underlayments such as gypsum concrete and lightweight concrete.
L&M Construction Chemicals
Since 1962 specifiers and buyers have chosen L & M Construction Chemicals for concrete treatment chemicals. Leaders in decorative, polished concrete with our FGS/PermaShine. Popular products include SEAL HARD, CRYSTEX grout, DURACRETE repair mortars, AQUAPEL water and salt repellents, and other products for concrete construction, protection and repair. We want to be your concrete resource.
Maxxon Corporation 
Maxxon®, the “Green” Floor Specialists, is recognized worldwide as the pioneer and leader in floor technologies. Maxxon provides a full spectrum of floor underlayments, from the original Gyp-Crete to Level-Right Self-Leveling Underlayments. Maxxon underlayments are now always “Green” and Acousti-Mat LPR, Acousti-Mat® II, Enkasonic®, and Acousti-Mat® 3 are made with 40% pre-consumer recycled content.
USG Performance Substrates
USG® is the only gypsum floor manufacturer that produces gypsum products. And only synthetic gypsum is used in Levelrock® Green floor underlayments for up to 94% green composition. In fact, all green Levelrock floor underlayments may contribute towards LEED® credits. See how USG’s world-class research team’s dedication to product development can benefit you.
See also:
09 8500 - Sound Transmission Control Materials for other methods of achieving an STC rating.
For complete Division 03 Concrete products and ingredients listings
Allied Custom Gypsum
AccuCrete® Brand Underlayment products are formulated to be used in a variety of floor underlayment applications, and are set apart from the competition by providing superior surface quality for adhered floor goods. All AccuCrete® Brand Underlayments are now available in Green Versions certified by UL Environment®. Allow us to assist you with your upcoming project.
Atlas Tech Products - CA, AZ, NV, NM, UT & CO
Atlas Tech Products provides self-leveling and trowelable floor underlayments to provide a level hard surface prior to installation of tile, wood, carpet and other flooring materials. Tech-Level Premier is self-leveling and can accept coverings after 24 hours. Feather Coat is a fast-drying trowelable skim coat that can accept coverings after 20 minutes.
Duraamen Engineered Products
Päram 5500 is calcium aluminate cement based self leveling concrete overlay for fast rack resurfacing and leveling existing substrates like wood/plywood, ceramic tile, VCT, etc. It can be applied from 1/8in to 1.5in in one pass. It can accept ceramic tiles and natural stone within 3-4 hours after its installation.
The Euclid Chemical Company
The Euclid Chemical Company designs and manufactures concrete and masonry admixtures, curing and sealing compounds, industrial coatings, structural grouts, epoxy adhesives, floor hardeners and toppings along with a comprehensive selection of restoration/repair materials. Marketed under the EUCO, EUCON, TAMMS, DURAL and SPEEDCRETE brands, Euclid Chemical offers a full line of new construction and repair materials.
Hacker Industries
Hacker Industries, Inc. offers a wide variety of FIRM-FILL brand gypsum concrete underlayments and acoustical control products for use over wood, steel deck, or concrete. With the proven performance of 2 billion square feet installed across North America, our products create a durable, sound-rated and fire-resistance surface for finished floor coverings.
Keene Building Products
Keene Building Products manufacturers 3-dimensional noise control products for multi-family apartments and condominiums to stop impact and airborne noise. Quiet Qurl® products are available with traditional moisture control (MC) fabric, MT (Muffling technology enhancement) and RF (reinforced fiberglass). These range in thickness from 0.125 inch-0.75 inch with underlayments such as gypsum concrete and lightweight concrete.
L&M Construction Chemicals
Since 1962 specifiers and buyers have chosen L & M Construction Chemicals for concrete treatment chemicals. Leaders in decorative, polished concrete with our FGS/PermaShine. Popular products include SEAL HARD, CRYSTEX grout, DURACRETE repair mortars, AQUAPEL water and salt repellents, and other products for concrete construction, protection and repair. We want to be your concrete resource.
Maxxon Corporation
Maxxon®, the “Green” Floor Specialists, is recognized worldwide as the pioneer and leader in floor technologies. Maxxon provides a full spectrum of floor underlayments, from the original Gyp-Crete to Level-Right Self-Leveling Underlayments. Maxxon underlayments are now always “Green” and Acousti-Mat LPR, Acousti-Mat® II, Enkasonic®, and Acousti-Mat® 3 are made with 40% pre-consumer recycled content.
USG Performance Substrates
USG® is the only gypsum floor manufacturer that produces gypsum products. And only synthetic gypsum is used in Levelrock® Green floor underlayments for up to 94% green composition. In fact, all green Levelrock floor underlayments may contribute towards LEED® credits. See how USG’s world-class research team’s dedication to product development can benefit you.