Guide Specification for DEPENDABLE GSL LITE
SECTION 03540

Self-Leveling, Lightweight, Polymer Modified, Gypsum Cement-Based Underlayment

Dependable GSL Lite is a lightweight, polymer-modified, gypsum cement, self-leveling underlayment. GSL Lite is a unique product that combines lightweight and versatility. It is designed for those applications where the added weight to the structure is a concern.

It is compatible with most substrates (including lightweight concrete, gypsum, suspended wood floors) as well as most floor covering adhesives.

This guide specification is for use by qualified design and construction professional s only, and must be edited to meet project requirements. For current product information and technical support, call Dependable at 1-800-227-3434.

PART 1 GENERAL

1.01 SUMMARY

1. Section Includes: Floor patching and leveling required prior to installation of floor coverings.  Scope of repair work [is shown on Drawings.] [includes ________________].]
2. Related Documents: Drawings, Conditions of Contract, Division 1 - General Requirements and other
   Contract Documents affect this Section.
3. Related Sections:
   1. Section [01100 – Alteration Project Procedures] [02070 – Selective Demolition for Remodeling].
   2. Section [09000 – Finishes].

1.02 REFERENCES

1. American Society for Testing and Materials:
   1. ASTM C472 - Compressive Strength of Gypsum, Gypsum Plaster, and Gypsum Concrete.
   2. ASTM C348 - Flexural Strength of Hydraulic Cement Mortars.
   3. ASTM C307 - Tensile Strength of Chemical Resistant Mortars, Grouts, and Monolithic Surfacings.
   4. ASTM C266 -Time of Setting of Hydraulic Cement Paste by Gilmore Needle.
   5. ASTM E1155 - Method for Determining Floor Flatness and Levelness Using the "F-Number" System.
   6. ASTM F1869 - Standard Test Method for Measuring the Moisture Vapor Emission Rate of a Concrete Subfloor.

1.03 SUBMITTALS

1. Submit:
   1. Manufacturer's product data sheets and installation instructions to prove compliance with specified requirements.
   2. [Sample of manufacturer's limited warranty and warranty application procedures.]

1.04 QUALITY ASSURANCE

Qualifications:

Contractor shall be knowledgeable and well trained in the use of floor underlayment materials.

The product supplied shall be Dependable, GSL Lite.

The material shall be compatible with concrete, wood, lightweight concrete, gypsum, suspended floors, metal, radiant heat tubing, and other floor substrates as required.The material shall be compatible with most floor covering adhesive, including requirements for surface alkalinity not to exceed a pH of 9.0.The material shall be lightweight.

Field Samples Application: At location on Project selected by [Architect] [Engineer], perform substrate                preparation work using methods proposed for Project. Notify Architect/Engineer to allow observation.                      Install a sample of material using similar techniques that will be used on the project.

The sample size shall be ___ft. x ___ft.  Accepted sample establishes standard for Work. Complete application when no longer needed for reference.

1.05 DELIVERY, STORAGE AND HANDLING

1. Comply with manufacturerâs instructions. Deliver in original, unopened packaging.  Store in dry conditions and protect from direct sun exposure, freezing, and extreme heat [greater then 105°F (41°C)].

1.06 PROJECT CONDITIONS

1. Environmental Requirements

1. Hot weather: Comply with ACI 305. Do not apply in extreme heat [greater than 105°F (41°C.)].
2. Cold weather: Comply with ACI 306. Do not apply when ambient, surface, or material temperature is below 50°F (10°C.).

PART 2 PRODUCTS

2.01 MANUFACTURERS

1. Dependable Chemical Company, phone 1-800-227-3434.
2. Substitutions: Comply with [Instructions to Bidders] [________________] for substitution request procedures.

2.02 MATERIALS

2.03 EQUIPMENT

1. Pumps: Comply with manufacturer’s instructions.
   
   Mixing devices: When mixing by drill and paddle method
   
   The drill should be at least __" in size and capable of generating 150 – 450 RPM.
   
   The paddle may be an epoxy mixer (egg beater / cage), jiffy mixer, rectangular speedy mixer, or other type designed not to entrain or entrap air.

PART 3 EXECUTION

3.01 PREPARATION

1. All substrates, regardless of type, must be solid, sound, clean, and primed.
   
   Concrete substrates: All concrete substrates must be sound, clean, and free of dirt, dust, grease, curing compounds, or any other material which might prevent adhesion. Application over textured surfaces will achieve the best bond. Concrete that has been steel troweled should be mechanically prepared (ie. Bead blast, scarified, etc.). Acid etching is not acceptable.
   
   Lightweight/Gypsum Subfloors: All substrates must be sound, clean and free of dirt, dust, grease or any other contaminant which might prevent adhesion. Remove any soft, dusty layers.
   
   Wooden substrates: All wooden substrates must be sound, clean and free of dirt, oils, or any other material which may prevent adhesion.  Depending upon the movement or deflection of the substrate, a metal lathe may be needed for reinforcement to provide increased flexural strength. Consult technical assistance.
   
   Adhesive residue: Using mechanical means, remove loose, brittle, or thick/heavy accumulations to a minimal well bonded residue. Make sure that proper removal and disposal procedures are used when dealing with asbestos containing adhesive.
   
   Existing tile: Existing ceramic tile, quarry tile, etc. must be well bonded. It must also be clean and free of waxes or any other material that might prevent adhesion.  Glazed or extremely smooth tile may require abrading the surface by mechanical means in order to achieve a proper bond.
   
   The substrate shall be watertight. Any holes, cracks, etc. shall be repaired prior to priming. Patching should be done with a like material, such as Polyskim or Skimcoat.
   
   The substrate shall be checked for moisture. Hydrostatic pressure or excessive moisture must be corrected. Consult technical assistance.

3.02 PRIMING

1. Prime all surfaces with Primer SL. Use a long-handled roller, soft bristle broom, or paint brush to apply Primer SL. Do not dilute. Apply evenly across the surface, removing any puddles or excess primer.  Coverage rates may vary depending upon the substrate and its porosity. Very porous substrates may require multiple coats. A membrane must form on the surface.
   
   Do not apply GSL Lite until the Primer SL is dry [about 1 hour @ 70°F (21°C) and 50% relative humidity]. Apply the GSL Lite the same day as the primer.

3.03 INSTALLATION

1. Mixing
   
   Use a clean mix container. Pour in proper amount of clean, cool water and add the powder slowly. If the mixing device does not produce a lump free mix, try using 2/3 of the water, adding all the powder until wet, and then add the remaining water.
   
   Water / powder ratio is 4 quarts (3.77 liters) of water to 27 pounds (12.15 kg) of powder.
   
   Mix material in a drum with a slow mixer at 150 – 450 RPM using a paddle or similar tool designed to avoid air entrapment. Mix for at least 2 minutes, but not more than 3 minutes to a homogeneous lump free consistency. 
   
   Larger quantities may be mixed in a mortar mixer. Carefully add materials to the mixer being careful to avoid spillage. Do not over water.
   
   Pumps may be used to place GSL Lite. Follow the instructions provided by the pump manufacturer, be careful to ensure proper mixing prior to placement. Please contact technical services for recommendations on pump equipment.
   
   When applying in thickness greater than 1" (25.4mm), aggregate may be added to the mix. GSL Lite may be placed up to 2" (75mm) in thickness in a neat state. Add no more than 15 lbs. (6.75 kg) of aggregate per 27 lb. (12.15 kg) bag. This mix is less flowable and may require further working. A subsequent neat layer may be needed to level and smooth the surface. Follow instructions for bonding additional layers (Section 3.03.A.6).
   
   When adding aggregate to the mix, mix GSL Lite as normal (as described in Step 3) and then slowly add aggregate to the mix. Mix thoroughly, making sure that the aggregate is completely coated.
   
   Pump or pour material on to the substrate. Do not re-temper or add water. GSL Lite is highly flowable for at least 20 minutes [@ 70°F (21°C.)]. The material can be moved with a screed set to an appropriate depth. Pumping should be continuous, being careful not to create any cold joints. Wear spiked shoes while working in the wet material to avoid leaving marks. If a fine edge is desired, the  edge should be steel troweled after initial set, but before it is completely hard. Once the GSL starts to set, stay off the floor until it has reached final set [approximately 2 hours @ 70°F. (21°C)]. (F-1)
   
   If the underlayment is to be placed in layers, allow the initial layer to harden, to the point where the material has lost its evaporative moisture. Next, prime and begin the subsequent application. The subsequent layer should be applied within 24 hours.
   
   The underlayment can receive floor covering when the product has lost its evaporative moisture, in about 24 hours at the minimum thickness at 70°F (21°C).
   
   Direct sunlight, heat, and wind can cause rapid drying of the product which can lead to reduced working time and workability. To avoid rapid drying, provide protection against these elements.
   
   Floor Covering Installation
   
   Most floorcovering is compatible and bonds well to the GSL Lite. Before installing a portland cement based thinset for ceramic, however, seal the GSL Lite with a latex primer/sealer compatible with the thinset. Primer SL or DEPENDABLE White Latex Liquid may be used.

3.04 PRECAUTIONS AND LIMITATIONS

1. Do not use over particle board, presswood, masonite, chipboard, Luaun, or similar dimensionally unstable materials, or any substrate not well bonded or free of movement.
   
   Do not use where surface or air temperature falls below 50°F (10°C) within 72 hours before or after installation or when finished floor is subject to freeze within 7 days.
   
   Do not install where hydrostatic pressure or excessive moisture emissions exceeds level permitted for floor covering to be installed.
   
   Do not use as a troweled patch or at less than natural minimum flow thickness.
   
   Do not use exterior.

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   F-1: The modification to ASTM C472 and ASTM C348 is that the samples are air dried until they are weight stable.
   
   F-2:  When timing is referenced, tests were conducted at 70°F (21°C) with a relative humidity of 50 – 60%.
   
   END OF SECTION