Products : Surface Prep : Waterproofing Membranes & Underlayments : Custom® 9240 Waterproofing and Anti-Fracture Membrane

Custom® 9240 Waterproofing and Anti-Fracture Membrane

A flexible, seamless waterproofing membrane with a liquid-applied polymer and reinforcing fabric that bonds to a variety of substrates and is ideal for heavy duty service installations. Designed for waterproofing tile and stone installations, Custom® 9240 also provides protection from fractures to 1/8" (3 mm) over shrinkage and other non-structural cracks.

  • Features & Benefits
  • Technical Documents
  • Warranty Information

Key Features

  • Waterproofing membrane rated for extra heavy-duty service
  • Anti-fracture protection up to 1/8" (3 mm)
  • Listed with IAPMO for use as a shower pan liner

Suitable Substrates

  • Concrete, cement mortar, masonry
  • Cement Backerboard
  • Exterior Plywood and OSB (interior, dry areas only)
  • Exterior Decks – Contact Technical Services
  • Post-Tension Concrete – Contact Technical Services
  • Lightweight Concrete (min. 2000 psi compressive strength)
  • Gypsum-Based cement topping (min. 2000 psi compressive strength)
  • Existing ceramic tile and resilient flooring

Composition & Materials

Custom® 9240 is a liquid-applied polymer with a reinforcing fabric.


  • Rated for extra heavy duty service
  • Forms flexible, seamless waterproofing for varying substrates
  • Provides anti-fracture protection to 1/8" (3 mm) for shrinkage and non-structural cracks
  • Meets Uniform Plumbing Code specifications for use as a shower pan liner


  • Do not apply to surfaces that may drop below 40°F (4°C) within 72 hours of application.
  • Do not apply over wet surfaces or surfaces subject to hydrostatic pressure.
  • Do not use to bridge or cover over existing expansion, control, construction, cold or saw cut joints; use Crack Buster® Pro Membrane for control, cold or saw cut joints.
  • Do not use as an adhesive.
  • Do not use as a wear surface; the membrane must be covered with tile or other permanent flooring.
  • Do not use solvents in conjunction with the membrane


  • 6 gallon (22.7 L) pail of liquid
  • 6" x 75' (0.15 x 22.85 M) fabric roll
  • 36" x 100' (0.91 x 30.5 M) fabric roll
  • Kit 6 gallon (22.7 L) pail of liquid and either 6" x 75' (0.15 x 22.85 M) or 36" x 100' (0.91 x 30.5 M) fabric roll

Technical Data

Applicable Standards

American National Standards Institute (ANSI) ANSI A108.01, A108.13, A108.17, A118.10 and A118.12 American National Standards for the Installation of Ceramic Tile ASTM International (ASTM)

  • ASTM C627 Standard Test Method for Evaluating Ceramic Floor Tile Installation Systems Using the Robinson-Type Floor Tester
  • ASTM D638 Standard Test Method for Tensile Properties of Plastics

Tile Council of North America (TCNA) TCNA Handbook for Ceramic Tile Installation, TCNA Method EJ171, F125 & F125A


Technical Data Sheet Technical Data Sheet - French Technical Data Sheet - Spanish Material Safety Data Sheet - English Material Safety Data Sheet - French

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 Custom® 9240 Waterproofing and Anti-Fracture Membrane 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

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