Product Description

DE NEEF® Flex LV PURe is a hydrophobic polyurethane designed to form a flexible gasket when injected into cracks and joints in concrete structures. DE NEEF® Flex LV PURe grout expands on contact with water and quickly cures to a tough, flexible foam that is resistant to most organic solvents, mild acids, alkali, petroleum and micro-organisms.

Product Advantages

  • Free Foam Expansion up to 18 times
  • Contains no volatile solvents
  • Single Component
  • Controlled reaction time
  • Improved low temperature performance
  • Flex Cat PURe liquid to -40°F

Product Applications

  • Sealing leaking cracks in concrete 0.02” and wider
  • Sealing moving and non-moving joints in concrete

Installation Guidelines

Warning: DE NEEF® Flex LV PURe must be used with DE NEEF® Flex Cat PURe. Consult the Technical Data Sheets and SDS before using.

Installation Instructions: For detailed installation instructions refer to the DeNeef technical bulletin for your applicatio

Catalyst: Shake catalyst can 2-3 minutes. Pour the desired amount of Flex LV PURe into a clean dry pail. Measure the appropriate amount of Flex Cat PURe (refer to the Reaction Times section of this data sheet for the desired set time) and pour it into the pail. Stir until adequately mixed. Exceeding the recommended amount of catalyst may adversely affect the reaction and quality of the cured foam.

Injection: During injection the grout will follow the path of least resistance. When the material has stopped penetrating it will continue to expand against the limits of the confined space and compress within itself,forming a dense, closed cell foam.

Extreme conditions: For application procedures in extreme temperatures and specific environments or equipment recommendations call the DE NEEF® Technical Service Department.

Cleaning: Clean all tools and equipment which have been in contact with the resin with DE NEEF® Washing Agent before resin has cured. Products should be disposed of according to local, state, and federal laws.

Reaction Times

40°F 1 17’00” 12V
  2 8’30” 14V
  5 4’00” 16V
60°F 1 10’50”  14V
  2 7’00”  16V
  5 3’05” 16V
77°F 1 9’00” 14V
  2 5’35” 16V
  5 2’10” 17V
86°F 1 7’30” 14V
  2 4’40” 16V
  5 1’45” 17V
95°F 1 6’45” 15V
  2 4’00” 17V
  5 1’35” 18V

Packaging & Handling


5 gallon metal pail
50 gallon metal drum

DE NEEF® Flex Cat PURe:

25 fl. oz. in 1 qt. metal cans

DE NEEF® Flex LV PURe is sealed under dry nitrogen because it is sensitive to moisture, and should be stored in original containers in a dry area. Storage temperature must be between 40°F and 90°F. Once the packaging has been opened, the useful life of the material is greatly reduced and should be used as soon as possible. Shelf life: 2 years.


DE NEEF® Flex LV PURe must be used with DE NEEF® Flex Cat PURe.

Low temperatures will significantly affect viscosity. Flex LV PURe is not designed for void filling and must be used in compression. If site temperatures are extremely low, heat bands or heated water baths may be used on the pails before and during installation to maintain the product’s temperature. Avoid splashing water into open containers, as the material is water activated. Avoid exceeding 90⁰F when warming.

CAUTION: pH NOTICE. Water used to activate PURe Grouts must be in the pH range of 3-10 for optimum foam quality.

Health and Safety

Always use protective clothing, gloves and goggles consistent with OSHA regulations. Avoid eye and skin contact. Do not ingest. Refer to SDS. For emergencies, call CHEMTREC 1-800-424-9300.


Solids 100% ASTM D2369
Viscosity 550 cps at 77°F ASTM D2196
Color Pale yellow  
Density 1.02 g/cm3  ASTM D4659
Flashpoint >270°F ASTM D93
Corrosiveness Non-corrosive  
Viscosity 15 cps at 77°F ASTM D2196
Color Clear to pale grey  
Flashpoint 221°F ASTM D93
Density confined 1.00 g/cm3 ASTM D3574
Density free about 3 PCF ASTM D3574
Tensile strength >174 psi ASTM D3574
Elongation % 100 ASTM D3574