Products : Setting : Additives : CustomCrete® Latex Mortar Admix

CustomCrete® Latex Mortar Admix

NOTE:  This product has been discontinued.

Formulated to be used with Thick Bed Mortar or as an additive to a site-mixed sand and cement blends to form a high strength thin-bed mortar. Adds flexibility and shock resistance for use in heavy traffic conditions in industrial, commercial and institutional installations. Frost-resistant, it's excellent for exterior use in cold climates. Also for use in wet areas and underwater installations such as pools and fountains. Use as an additive with Thick Bed Mortar or to a site-mixed sand and cement blend.

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Key Features

  • Mix with Thick-Bed Mortar or a basic sand and cement mix 3:1
  • Adds shock resistance and flexibility
  • Excellent for exterior use and underwater installations


Applicable Standards

American National Standards Institute (ANSI) ANSI A108.5; A118.4; A118.11 of the American National Standards for the Installation of Ceramic Tile

Tile Council of North America (TCNA) TCNA Handbook for Ceramic Tile Installation, TCNA Method EJ171

Conformance to Building Codes

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

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
  • Up to 1 point towards IEQ Credit 4.1, Low-Emitting Materials – Adhesives & Sealants

Suitable Tile Types

  • Vitreous, semi-vitreous or non-vitreous tile: ceramic, mosaic, quarry, cement body tile
  • Impervious porcelain and glass tile
  • Brick and stone veneer
  • Cement-based precast terrazzo
  • Natural stone tile

Suitable Substrates

  • Concrete, mortar beds, masonry, Portland cement plaster
  • WonderBoard® Lite cement backerboards
  • Liquid applied waterproofing membranes such as RedGard® and Custom® 9240
  • Crack prevention sheet membranes such as Crack Buster® Pro
  • Exterior Grade Plywood (interior residential and light commercial dry areas)
  • Gypsum wallboard (interior dry areas)
  • Existing ceramic tile
  • Fully-bonded sheet vinyl flooring
  • Plastic laminates
  • Cutback adhesive (see preparation instructions)

General Surface Prep

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

Surfaces must be structurally sound, clean, dry and free from grease, oil, dirt, curing compounds, sealers, adhesives or any other contaminant that would prevent a good bond. Glossy or painted surfaces must be sanded, stripped and cleaned of waxes, dirt or any contaminants. Concrete must be cured 28 days and accept water penetration. Concrete must be free of efflorescence and not subject to hydrostatic pressure. Concrete slabs should have a broomed or brushed finish to enhance the bond. Plywood flooring including those under resilient flooring must be structurally sound and meet all ANSI and deflection requirements. For questions about proper subfloor installation, call Technical Services. Smooth concrete surfaces, existing glazed tile, terrazzo, or polished stone should be roughened or scarified. Sheet vinyl must be-well bonded and stripped of old finish. Roughen the surface by sanding or scarifying, rinse and allow to dry. Expansion joints should never be bridged with setting material. Do not sand flooring materials containing asbestos. Ambient temperature, surfaces and materials should be maintained at a temperature above 50° F (10° C) or below 100° F (38° C) for 72 hours.

Health Precautions

Do not take internally. Avoid eye and skin contact. If eye contact occurs, immediately flush with water for 15 minutes and consult a physician.

Limitations to the Product

Bonding to Concrete Surfaces

Concrete or plaster must be fully cured and must accept water penetration. Test by sprinkling water on various areas of the substrate. If water penetrates, then a good bond can be achieved; if water beads, surface contaminants are present, and loss of adhesion may occur. Contaminants should be mechanically removed before installation. Concrete must be free of efflorescence and not subject to hydrostatic pressure. Concrete slabs should have a broomed or brushed finish to enhance the bond. Smooth concrete slabs must be mechanically abraded to ensure a good bond.

Bonding to Plywood Surfaces

Plywood floors, including those under resilient flooring, must be structurally sound and must meet all ANSI A108.01 Part 3.4 requirements. See TCNA F150. For questions about proper subfloor installation, call Custom® Building Products.

Bonding to Backerboards

WonderBoard® Lite Backerboard may be installed over plywood subfloors as an alternative to an additional layer of plywood,. Refer to TCNA F144.

Bonding to Existing Surfacing Material

Plywood flooring must be structurally sound and meet all ANSI and deflection requirements. Resilient flooring or plastic laminates must be well-bonded, clean and free of all contaminates. Roughen the surface by sanding or scarifying, rinse and allow to dry. Do not sand flooring containing asbestos. For existing well-bonded ceramic tile, mechanically abrade with carborundum stone. Rinse and allow to dry. When sanding we recommend the use of an approved respirator.

Bonding to Cutback Adhesive

Adhesive layers must be removed as they reduce mortar bond strength to cement surfaces. Use extreme caution as 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. Do a test bond area first, to determine desirable results. Refer to the RFCI Pamphlet, "Recommended Work Practices for Removal of Resilient Floor Coverings", for further information.

Mixing Ratios

Thoroughly mix a 50 lb (22.68 kg) bag of mortar with 5 quarts (4.73 L) CustomCrete® Latex Mortar Admix to a smooth, paste-like consistency. For a sand/cement site mix, dry blend one 94 lb (42.68 kg) bag of Portland cement with one 100 lb (45.36 kg) bag of #60 silica sand and mix with 5 gallons (18.93 L) of CustomCrete®.

Mixing Procedures

Mix by hand or use a low speed (150-200 RPM) 1/2" (13 mm) drill. Let slake or stand 5-10 minutes, stir again and use. Stir occasionally to keep fluffy, but do not re-temper (add more additive). When properly mixed, troweled ridges will stand with little or no slump.

Application of Product

Refer to the Thick Bed Mortar directions for proper surface preparation and application instructions.

Curing of Product

Allow to cure for a minimum of 24 hours before grouting or light traffic, depending upon temperature and humidity. In areas that will be continually wet (e.g. swimming pools, fountains), it's recommended that the completed installation be cured a minimum of 14 days and allowed to thoroughly dry before water submersion. Curing times vary with weather conditions and humidity; special conditions may require curing up to 28 days.

Cleaning of equipment

Clean with soap and water before material dries. Cured material is difficult to clean from surfaces.


Keep from freezing. Close container after each use.

Product Maintenance

Properly installed product requires no special maintenance.

Expected Wear

Properly installed tile will last for more than 60 years.

Ordering Information


  • 5 gallon (18.93 L) pail
  • 55 gallon (208.19 L) drum

Warranty Information

Product Warranty

Obtain the applicable LIMITED PRODUCT WARRANTY at or send a written request to Custom Building Products, Inc., Five Concourse Parkway, Atlanta, GA 30328, USA. Manufactured under the authority of Custom Building Products, Inc. © 2017 Quikrete International, Inc.

Coverage Chart


Trowel Size Min Coverage Max Coverage
1/4" x 1/4" x 1/4" (6 x 6 x 6 mm) square-notch 80 sq. ft. (7.4 M²) 100 sq. ft. (9.3 M²)

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