Products : Surface Prep : Self-Leveling Underlayments : LevelQuik® RS (Rapid Setting) Self-Leveling Underlayment

LevelQuik® RS (Rapid Setting) Self-Leveling Underlayment

Helps level floors prior to the installation of ceramic tile, natural stone, resilient flooring, carpet, wood and other floor coverings. This quick-setting underlayment can be applied to 1.5" (3.8 cm) thick in one pour and seeks its own level in minutes. With proper installation, the use of LevelQuik® RS can achieve an extra heavy rating for high impact use in food plants, dairies, breweries and kitchens. LevelQuik RS may be applied to in residential structures with floor joists up to 24" o.c. Formulated using Controlled Cure Technology®, LevelQuik RS helps eliminate installation problems such as bond failure, crumbling and staining of resilient flooring caused by the free moisture found in traditional underlayments.

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Key Features

  • Seeks its own level in minutes
  • Levels from feather edge to 1.5" in one pour
  • Walkable in 4 hours
  • Exceeds TCNA requirements for ceramic tile installations


Suitable as an Underlayment for:

  • Vitreous, semi-vitreous or non-vitreous tile
  • Ceramic, mosaic or quarry tile
  • Impervious porcelain and glass tile
  • Cement-based precast terrazzo
  • Natural stone tile
  • Carpet
  • Wood, parquet
  • Vinyl composition tile (VCT)
  • Sheet vinyl flooring
  • Laminated flooring


  • Can be applied from feather edge to 1.5" (3.8 cm) thick in a single pour
  • Reduces bond failure and crumbling of resilient flooring
  • Cures fast and develops high early strength for quick installation
  • Rated for Extra Heavy use per ASTM C627
  • Rated for Residential use over wood subfloors with joists to 24" (61 cm) per ASTM C627


Applicable Standards

ASTM International (ASTM)

  • ASTM C1708 Standard Test Methods for Self-leveling Mortars Containing Hydraulic Cements
  • ASTM C627 Standard Test Method for Evaluating Ceramic Floor Tile Installation Systems Using the Robinson-Type Floor Tester
  • ASTM F1869 Standard Test Method for Measuring Moisture Vapor

Resilient Floor Covering Institute (RFCI) Recommended Work Practices for Removal of Resilient Floor Coverings
Tile Council of North America (TCNA) TCNA Handbook for Ceramic Tile Installation, TCNA Method EJ171
American National Standards Institute (ANSI) ANSI A108.01 and A108.02 of the American National Standards for the Installation of Ceramic Tile

Conformance to Building Codes

Installation must comply with the requirements of all applicable local, state and federal code jurisdictions.

Composition of Product

LevelQuik© is a proprietary dry blend of copolymers, cements, and inorganic chemicals.

Environmental Consideration

Custom® Building Products is committed to environmental responsibility in both products produced and in manufacturing practices. Use of this product can contribute towards LEED® v3 certification:

  • Up to 2 points towards MR Credit 5, Regional Materials

Suitable Substrates

  • Absorbent concrete
  • Non-absorbent concrete
  • Lightweight concrete
  • Gypsum-based underlayments
  • Existing ceramic tile
  • Cement terrazzo
  • Exterior grade plywood
  • OSB
  • Cutback adhesive residue
  • Prepared VCT

General Surface Prep

USE CHEMICAL-RESISTANT GLOVES, such as nitrile, when handling product.

All surfaces must be structurally sound, clean, dry and free from contaminants that would prevent a good bond. Concrete must be fully cured. Concrete surfaces should be primed with LevelQuik Latex Primer. Smooth concrete surfaces, existing glazed tile, terrazzo, or polished stone may need to be roughened or scarified. For increased performance in demanding applications, concrete surfaces can be mechanically profiled and prepared by shotblasting, sandblasting, water-jetting, scarifying, diamond-grinding or other engineered approved methods (reference ICRI CSP 3 standards for acceptable profile height). CUSTOM's MBP Multi-Surface Bonding Primer may be used as an alternative to profiling the surface.

Block penetrations in the substrate and walls to prevent leveler from flowing into adjoining rooms. Perimeter space, created with foam strips or by other means, may be required over suspended slabs when product is applied in thick applications.

Movement Joint Placement

Movement joints are required for perimeters and other changes of plane in all installations. See TCNA Detail EJ171 for recommendations.


Prime all surfaces with LevelQuik Latex Primer or appropriate surface primer before application.

Joints or Cracks in Substrate

Expansion joints and cold joints, as described in ANSI A108.01, should be carried from the substrate up through the tile or flooring surface and filled with an appropriate elastomeric sealant, such as Custom's® 100% Silicone Caulk. For the proper treatment of control or saw cut joints and cracks for flooring, refer to ASTM F710. For tile installations, refer to TCNA Details EJ171, F125 & F125A. Contact Custom's® Technical Services for additional information.

Health Precautions

This product contains Portland cement. Avoid eye contact or prolonged contact with skin. Wash thoroughly after handling. If eye contact occurs, flush with water for 15 minutes and consult a physician. Use with adequate ventilation; do not breathe dust and wear a NIOSH approved respirator. If ingested, do not induce vomiting; call a physician immediately.

Limitations to the Product

  • Do not bond directly to hardwood, Luan plywood, particle board, parquet, cushion or sponge-back vinyl flooring, metal, fiberglass or plastic. Contact CUSTOM technical services for recommendations.
  • Do not use when the temperature is below 50°F (10°C) or above 90°F (32°C).
  • Do not use as a permanent wear surface.
  • Do not use on sloped surfaces that require drainage.
  • Precautions should be taken when applying over post-tensioned concrete, pre-stressed concrete or prefabricated concrete planks. Contact CUSTOM technical services for further details.
  • For installations over metal decks, contact CUSTOM technical services for recommendations.
  • This product is suitable for use in exterior conditions as an underlayment in areas that are not prone to water immersion or prolonged exposure to temperatures above 120°F (50°C).

Bonding to Concrete Surfaces

Contaminants or curing compounds should be mechanically removed before installation. Concrete must be free of efflorescence and not subject to moisture beyond the floor covering manufacturers' limits or hydrostatic pressure. Lightweight concrete surfaces must have a tensile strength in excess of 200 psi (1.4 n/mm²).

Bonding to Plywood Surfaces

Plywood floors, including those under resilient flooring, must be structurally sound and must meet all industry guidelines. A 2.5 lb/yd² metal lath must be fastened every 6" - 8" (15 - 20 cm) with fasteners that have a galvanized or corrosion-resistant coating over primed surface. A minimum of a 1/2" pour is required for single layer plywood; for multi-layered plywood, the lath must be fully encapsulated. For questions about proper subfloor installation, call Custom Technical Services.

OSB Underlayments

OSB underlayments should be coated with 10-15 mils of RedGard® Waterproofing and Crack Prevention Membrane prior to priming with LevelQuik Latex Primer. A 2.5 lb/yd² metal lath must be fastened every 6" - 8" (15 - 20 cm) with fasteners that have a galvanized or corrosion-resistant coating. A minimum of 1/2" (12.7 mm) of LevelQuik RS can be applied over this properly prepared OSB.

Bonding to Gypsum Surfaces

Gypsum-based underlayments must obtain a minimum 2000 psi (13.8 MP) compressive strength. The underlayment must be sufficiently dry and properly cured to the manufacturer’s specifications for permanent, non-moisture permeable coverings.  Surfaces must be structurally sound and subject to deflection not to exceed the current industry standards.  Surfaces shall be free of all grease, oil, dirt, dust, curing compounds, waxes, sealers, efflorescence, or any other foreign matter.

All Gypsum surfaces should be primed with a properly applied sealer or a primer coat of RedGard, consisting of 1 part RedGard diluted with 4 parts clean, cool water. Mix in a clean bucket at low speed to obtain a lump-free solution. The membrane can be brushed, rolled or sprayed to achieve an even coat. Apply the waterproofing coat to the floor at a rate of 300 sq. ft.l (7.5 sq. m/L). Drying time depends on site conditions, but is normally less than 1 hour. Extremely porous surfaces may require 2 coats. At this point, LevelQuik Latex Primer and LevelQuik RS can be applied to the primed lightweight or gypsum based surface. Refer to the individual product data sheet or packaging directions for application instructions. Expansion joints must be installed in accordance with local building codes and industry guidelines.

Bonding to Cutback Adhesive

Adhesive layers must be removed. Use extreme caution; adhesives may contain asbestos fibers. Do not sand or grind adhesive residue, as harmful dust may result. Never use adhesive removers or solvents, as they soften the adhesive and may cause it to penetrate into the concrete. Adhesive residue must be wet-scraped to the finished surface of the concrete, leaving only the transparent staining from the glue. To determine desirable results, do a test bond area before starting. Refer to the RFCI Pamphlet "Recommended Work Practices for Removal of Resilient Floor Coverings" for further information.

Mixing Ratios

Mix the entire 50 lb (22.68 kg) bag of powder with 5.25 - 5.75 quarts (5 - 5.4 L) of clean, cool water.

Mixing Procedures

Mix 50 lb. (22.68 kg) bag of powder with the appropriate amount of clean, cool water. Slowly add powder to water while mixing with a heavy-duty 1/2" (13 mm) electric drill and an “egg-beater” mixing paddle at minimum 650 RPM. Thoroughly mix for 2 minutes to a lump-free consistency. Do not overmix. Overmixing or moving the mixer up and down during the mixing process could trap air, which could shorten the pot life or cause pinholing during application and curing.

Application of Product

Apply LevelQuik Latex Primer according to the specifications on its technical data sheet prior to the application of LevelQuik RS.

Pour LevelQuik RS, then spread with a long-handled gauged spreader. LevelQuik RS will seek its own level during the first 20 minutes. For featheredging and touch-ups, use a smoothing tool. Can be applied up to 1.5" (3.8 cm) thick in one application. If a second layer is required, install immediately after the first layer has set to a walkable hardness. If the first layer has dried over 12 hours, re-prime before second application. The surface will dry to a walkable hardness in 2 - 4 hours. For pumping and large scale applications, contact Custom's Technical Services Department for more information.

Curing of Product

Install non-moisture-sensitive ceramic tile or stone in 4 hours; most floor coverings can be installed after 16 hours. Drying time can vary with temperature and humidity. Test for moisture content before applying vinyl or wood flooring to the surface of the self-leveling underlayment.

Cleaning of equipment

Clean with water before the material dries.

Product Maintenance

Properly installed product requires no special maintenance. LevelQuik® RS is not recommended as a finish or wear surface.

Expected Wear

Properly installed tile will last for more than 60 years.

Ordering Information


50 lb (22.68 kg) bags

Warranty Information

Product Warranty

Custom® Building Products warrants to the original consumer purchaser that its product shall be free from defects in material and workmanship under normal and proper usage for a period of one year following the date of original purchase. Custom's® sole liability under this warranty shall be limited to the replacement of the product. Some states, countries or territories do not allow the exclusion or limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you. This warranty will not extend to any product which has been modified in any way or which has not been used in accordance with Custom's® printed instructions. Custom® makes no other warranties either expressed or implied. This warranty gives you specific legal rights, and you may have other rights that vary from state to state or from one country/territory to another.  This warranty is not transferrable.

Warranty Duration

When LevelQuik® RS (Rapid Setting) Self-Leveling Underlayment is used as a part of a qualifying full installation system of CUSTOM products, the installation can qualify for up to a lifetime system warranty. CUSTOM will repair and/or replace, at its discretion, the affected area of the system. For more information, find details and limitations to this warranty at

Product Videos


Coverage Chart


1/8" (3.18 mm) 50 ft² (4.6 M²)
1/4" (6.35 mm) 25 ft² (2.3 M²)
1/2" (12.7 mm) 12.5 ft² (1.15 M²)
1" (25.4 mm) 6.25 ft² (0.56 M²)
1.5" (38.1 mm) 4.17 ft² (0.38 M²)

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