CBIS Korfil
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KORFIL Block Insulation Inserts for Concrete Masonry Units


Basic Use: KORFIL Inserts are individually molded of expandable polystyrene and designed to fit standard two (2) core masonry units of 6, 8, 10 and 12-inch widths for use in both single wythe and cavity wall construction. Inserts are preinstalled at the block plant prior to delivery on the job site. In addition to nearly doubling the insulating characteristics of a masonry wall, KORFIL Inserts:

  • Eliminate the need for on-site labor to insulate masonry walls.
  • Do not deteriorate in insulation R-value with moisture or aging.
  • Allow space within the cores for the escape of moisture. This space also allows for easy installation of utilities within the wall.
  • Can be handled by masons just as easily as uninsulated blocks.
  • Are cost-competitive when compared to the various other methods used to insulate concrete blocks.
  • Have no effect on the fire rating of conventional concrete block walls.
  • Improve both the dewpoint and sound transmission resistance of ordinary concrete blocks.

Limitations: Expanded polystyrene products of any type should not be exposed to temperatures in excess of 184�F.

KORFIL Inserts are made from flame-retardant treated expandable polystyrene. Like all foamed plastics, good fire procedures must be followed during storage and installation. Inserts give off no toxic products of combustion, except carbon monoxide and carbon dioxide, concentrations of which are far less than those given off by equal volumes of wood products. Expandable polystyrene contains no fluorocarbons and no formaldehyde.

Composition and Materials: KORFIL Inserts are individually molded from expandable polystyrene in a density range of 0.90 to 1.14 lbs. per cu. ft. Inserts are packaged at the point of manufacture in heat-sealed, clear polyethylene bags.

Applicable Standards:

  • ASTM C 578. Type 1, Specification for Rigid Cellular Polystyrene Thermal Insulation.
  • ASTM C 90. Specification for Load-Bearing Concrete Masonry Units.

Technical Data: The Thermal Properties tables show the thermal resistance (Rt), including inside and outside air surface resistances of .68 and .17 hr-ft2-�F/BTU, respectively, and the U-values for various densities of concrete masonry units.

Physical Characteristics: See Physical Properties chart.


Preparatory Work: None required. Inserts are placed in blocks prior to delivery to the job site. Inserts do not affect the handling of blocks so no added labor is involved.

Precautions: During storage and installation, good fire safety procedures should be followed. Care should also be taken to make certain all broken or damaged inserts are replaced.

Availability and Cost

Availability: KORFIL Inserts are manufactured under protection of a United States Patent. They are sold only to concrete block manufacturers. Contact a CBIS/KORFIL representative for order and delivery information. KORFIL Inserts are nonproprietary.

Cost: Specific price information is available only through local block manufacturers.

Warranty: KORFIL products are warranted to meet published specifications at the time of delivery. For further information, contact a CBIS/KORFIL representative.

Maintenance: No maintenance is necessary.

Technical Services: Support is provided by full-time, technically-trained CBIS/KORFIL sales representatives and technical service personnel, backed by a central research and development department and technical service staff.

Filing Systems Sweets

We hope the information given here will be helpful. It is based on data and knowledge considered to be true and accurate and is offered for the user�s consideration, investigation and verification. Nothing contained herein constitutes a representation but we do not warrant the results to be obtained. Please read all statements, recommendations or suggestions in conjunction with our Conditions of Sale which apply to all goods supplied by us. No statement, recommendation or suggestion is intended for any use which would infringe any patent or copyright.

KORFIL is a registered trademark of Concrete Block Insulating Systems, Inc.

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