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Crack-Pac® Flex-H2O™ Polyurethane Crack Sealer

Restoration Products

This product's information may differ depending on the category of use. You are currently viewing details related to Restoration Products. You can also view product information related to the category: Urethane Injection

The Crack-Pac Flex-H2O polyurethane injection resin seals leaking cracks, voids or fractures from 1/32" to 1/4" wide in concrete or solid masonry. Designed to perform in applications where water is seeping or mildly leaking from the crack, the polyurethane is packaged in the cartridge and an accelerator is packaged in the nozzle. When the resin encounters water as it is injected into the crack, it becomes an expanding foam that provides a flexible seal in leaking and non-leaking cracks.

Key Features

  • Can be dispensed with a standard caulking tool
  • Can also be used on dry cracks if water is introduced to affected area
  • Can be used with a reduced amount or without accelerator to slow down reaction time
  • Expands to fill voids and seal the affected area
  • Fast reacting — reaction begins within 1 minute after exposure to moisture; expansion may be completed within 3 minutes (depending on the amount of moisture and the ambient temperature)
  • 20:1 expansion ratio (unrestricted rise) means less material needed
Model No. Option Packaging Qty. Carton Qty. Compatible Tools
CPFH09 Flex-H2O 9 oz. cartridge 1 12 CDT10S
CPFH09KT Flex-H2O (2) 9 oz. cartridge kit 2 2 CDT10S
FH05 Bulk: Flex-H2O Resin (5 gal.) / Flex-H2O Catalyst (16 oz.) 1


  • Polyurethane — clear, accelerator — green, cured — green

Storage Conditions

  • For best results, store in a dry area between 45°F (7°C) and 90°F (32°C). Product is very moisture sensitive.

Usage Temperature

  • 60°F (16°C) to 90°F (32°C)

Shelf Life

  • 12 months from the date of manufacture, unopened


  • Suitable for sealing cracks ranging from 1/32" to 1/4" wide in concrete and solid masonry.
  • Suitable for repair of cracks in dry, damp and wet conditions with excellent results. Designed to perform in applications where water is seeping or mildly leaking from the crack.
  • In order for components to mix properly, the resin and hardener must be conditioned to 60°F (16°C) to 90°F (32°C) before mixing.
  • For standard reaction time, use 30:1 resin to catalyst ration. For a faster reaction time, add more catalyst; for a slower reaction time, use less.

Clean Up

Uncured material — Wipe up with cotton cloths. If desired scrub area with abrasive, water-based cleaner and flush with water. If approved, solvents such as ketones (MEK, acetone, etc.), lacquer thinner, or adhesive remover can be used. DO NOT USE SOLVENTS TO CLEAN ADHESIVE FROM SKIN. Take appropriate precautions when handling flammable solvents. Solvents may damage surfaces to which they are applied. Cured material — scrape or brush off surface with a putty knife or wire brush. Tip: wetting the concrete or masonry surface immediately prior to injection will make cured resin easier to remove.


Crack-Pac Flex-H2O injection epoxy is also available in the Crack-Pac Flex-H2O Injection Kit (CPFH09KT). The kit includes everything needed to pressure inject cracks.

  • 2 Crack-Pac Flex-H2O cartridge/nozzle sets (CPFH09)
  • 12 E-Z-Click injection ports
  • 2 E-Z-Click injection fittings with 12" tubing
  • 1 pint of ETR paste-over epoxy (8 oz. of resin + 8 oz. of hardener)
  • 4 disposable wood paste-over applicators
  • 1 pair latex gloves

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