RECOMMENDED SPECIFICATION FOR GYP-CRETE 2000®/3.2K FLOOR UNDERLAYMENT FOR WOOD FRAME COMMERCIAL CONSTRUCTION
Summary
This is the recommended specification for Gyp-Crete 2000/3.2K Floor Underlayment for wood frame commercial construction.
Section Includes
- Gyp-Crete 2000/3.2K gypsum cement
- Maxxon Floor Primer
- Maxxon Overspray
Quality Assurance
Installer's Qualifications: Installation of Gyp-Crete 2000/3.2K shall be by an applicator authorized by the Maxxon Corporation using Maxxon approved mixing and pumping equipment.
DELIVERY, STORAGE AND HANDLING
General Requirements: Materials shall be delivered in their original, unopened packages, and protected from exposure to the elements. Damaged or deteriorated materials shall be removed from the premises.
SITE CONDITIONS
Environmental Requirements: Before, during and after installation of Gyp-Crete 2000/3.2K, building interior shall be enclosed and maintained at a temperature above 50 degrees F (10 degrees C).
Products
Materials
Gypsum Cement: Floor underlayment Gyp-Crete 2000/3.2K gypsum cement as manufactured by the Maxxon Corporation, Hamel, MN. All others must receive prior approval.
Sand Aggregate: Sand shall be 1/8 inch (3 mm) or less, washed masonry or plaster sand, meeting requirements of Maxxon Corporation Sand Specifications 101.
Mix Water: Potable, free from impurities.
Subfloor Primer: Maxxon Floor Primer
Sealer: Maxxon Overspray
Mix Designs
General Requirements: Mix proportions and methods shall be in strict accordance with product manufacturer recommendations.
EXECUTION
PREPARATION
Condition and Cleaning of Subfloor: Subfloor shall be structurally sound. General Contractor shall clean subfloor to remove mud, oil, grease, and other contaminating factors before the arrival of the Gyp-Crete 2000/3.2K underlayment crew.
Leak Prevention: Fill cracks and voids with a quick setting patching or caulking material where leakage of Gyp-Crete 2000/3.2K could occur.
Priming Subfloor: Prime the subfloor using the Maxxon Floor Primer. Priming instructions may vary according to the type of substrate, multiple coats may be necessary.
Expansion Joints: Allow joints to continue through the Gyp-Crete 2000/3.2K at the same width.
APPLICATION OF CEMENTITIOUS FLOORING
Scheduling: Application of Gyp-Crete 2000/3.2K shall not begin until the building is enclosed, including roof, windows, doors and other fenestration. Install after drywall installation unless tenant finish requirements identify partitioning after the pour.
Application: Place Gyp-Crete 2000/3.2K at 3/4 inch (19 mm) minimum over wood frame. Spread and screed Gyp-Crete 2000/3.2K to a smooth surface. Except at authorized joints, place Gyp-Crete 2000/3.2K as continuously as possible until application is complete so that no Gyp- Crete 2000/3.2K product slurry is placed against Gyp-Crete 2000/3.2K product that has obtained its initial set.
Drying: General Contractor shall provide continuous ventilation and adequate heat to rapidly remove moisture from the area until the Gyp-Crete 2000/3.2K is dry. General Contractor shall provide mechanical ventilation if necessary. Under the above conditions, for 3/4 inch (19 mm) thick Gyp-Crete 2000/3.2K, 5-7 days is usually adequate drying time. To test for dryness, tape a 24 inch by 24 inch (609 mm by 609 mm) section of plastic or high density rubber mat to the surface of the underlayment. After 48-72 hours, if no condensation occurs, the underlayment shall be considered dry. Perform dryness test 5-7 days after pour.
PREPARATION FOR INSTALLATION OF GLUE DOWN FLOOR GOODS
Sealing: Seal all areas that receive glue down floor goods with Maxxon Overspray according to the Maxxon Corporation's specifications. Any floor areas where the surface has been damaged shall be cleaned and sealed regardless of floor covering to be used. Where floor goods manufacturers require special adhesive or installation systems, their requirements supersede these recommendations.
Floor Goods Procedures: See the Maxxon Corporation's "Procedures for Attaching Finished Floor Goods to Maxxon Underlayments" brochure for guidelines for installing finished floor goods. This procedure is not a warranty and is to be used as a guideline only.
FIELD QUALITY CONTROL
Slump Test: Gyp-Crete 2000/3.2K mix shall be tested for slump as it's being pumped using a 2 inch by 4 inch (50 mm by 101 mm) cylinder resulting in a patty size of 8 inches (203 mm) plus or minus 1 inch (25 mm) diameter.
Field Samples: At least one set of 3 molded cube samples shall be taken from each day's pour during the Gyp-Crete 2000/3.2K application. Cubes shall be tested as recommended by the Maxxon Corporation in accordance with modified ASTM C 472. Test results shall be available to architect and/or contractor upon request from applicator.
PROTECTION
Protection From Heavy Loads: During construction, place temporary wood planking over Gyp-Crete 2000/3.2K wherever it will be subject to heavy wheeled or concentrated loads.