Products : Setting : Thick Bed Mortar : Thick Bed Bedding Mortar

Thick Bed Bedding Mortar

Pre-blended underlayment specifically designed to float a mortar bed for ceramic tile. It is easy to mix and use, eliminating the need for site mixing of sand and cement. Thick Bed Bedding Mortar's 3:1 mix ratio provides a high-strength surface ideal for tiling commercial and industrial installations.

  WHERE TO BUY Not all products are sold at all stores. Please call the distributor to ensure product availability.
Have a question?


Key Features

  • Pre-blended; no job-site blending required
  • Easy to mix and use


Applicable Standards

American National Standards Institute (ANSI) ANSI A108.1 of the American National Standards for the Installation of Ceramic Tile ASTM International (ASTM)

  • ASTM C109 Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2-in.or [50-mm] Cube Specimens)
  • ASTM C627 Standard Test Method for Evaluating Ceramic Floor Tile Installation Systems Using the Robinson-Type Floor Tester 

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

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

Suitable Substrates

  • Interior or exterior floors
  • Concrete, masonry
  • Gypsum wallboard (interior dry areas)
  • Exterior Grade Plywood (interior dry areas)

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.

Application Over Plywood Substrates

Do not apply directly to plywood. Use vapor barrier and metal lath. Plywood floors, including those under resilient flooring, must be built to industry standards. Deflection should not exceed L/360. For questions about proper subfloor installation, call Technical Services.

Movement Joint Placement

Expansion joints and cold joints, as described in ANSI A108.01, should never be bridged with setting material. They must be brought through the tile work and filled with an appropriate elastomeric sealant, such as Custom's® 100% Silicone. Contact Custom's® Technical Services for the proper treatment of control or saw cut joints. Refer to TCNA EJ171, F125 and F125A.

Health Precautions

This product contains Portland cement and free silica. 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. Do not breathe dust; wear a NIOSH approved respirator. KEEP OUT OF REACH OF CHILDREN. DO NOT TAKE INTERNALLY.

Limitations to the Product

  • Do not apply directly over wood, metal, fiberglass, plastic and OSB panels lightweight concrete, gypsum underlayment, OSB, particle board, hardwood or Parquet floors.

Mixing Ratios

Mix with 2.4 L (2-1/2 quarts) of cool clean water or, for added strength, mix with 1.2 L (1 1/4 quarts) Thin-Set Mortar Admix and 1.2 L (1-1/4 quarts) of cool, clean water and 22.68 kg (50 lbs) powder together to a semi-damp, dry-pack consistency.

Application of Product

Refer to ANSI A108.1 A, B, or C for installation methods.

Curing of Product

Curing time is affected by ambient and surface temperatures and humidity. Use the following as a guideline. Allow 24 hours before grouting or light traffic.

Cleaning of equipment

Clean with water before material dries.


Store in a cool, dry area.

Product Maintenance

Properly installed product requires no special maintenance.

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.

Coverage Chart


Thickness Min Coverage Max Coverage
1/2" (13mm) 9 ft² (0.8 m²) 11 ft² (1 m²)
1" (25mm) 4.5 ft² (0.4 m²) 5.5 ft² (0.5 m²)

© 2016 Custom Building Products. All Rights Reserved.