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Exhibit 21


BUILDING MATERIALS CORPORATION OF AMERICA

LIST OF SUBSIDIARIES

COMPANY

  STATE OF INCORPORATION
BMCA Acquisition Inc.    Delaware
  Elkcorp   Delaware
    Elk Premium Building Products, Inc.    Delaware
      Elk Corporation of Texas   Nevada
      Elk Corporation of Alabama   Delaware
      Elk Corporation of Arkansas   Arkansas
      Elk Corporation of America   Nevada
      Elk Slate Products, Inc.    Delaware
      Elk Performance Nonwoven Fabrics, Inc.    Delaware
      Elk Composite Building Products, Inc.    Delaware
      Elk VersaShield Building Solutions, Inc.    Delaware
      RGM Products, Inc.    California
        Ridgemate Manufacturing Company, Inc.    California
    Elk Technology Group, Inc.    Delaware
      Chromium Corporation   Delaware
      Lufkin Path Forward, Inc.    Texas
      Elk Technologies, Inc.    Delaware
      Midland Path Forward, Inc.    Nevada
    Elk Group, Inc.    Nevada
    NELPA, Inc.    Nevada
      Elk Group, LP(1)   Texas
BMCA Gainesville LLC   Delaware
BMCA Quakertown Inc.    Delaware
BMCA Insulation Products Inc.    Delaware
Building Materials Investment Corporation   Delaware
Building Materials Manufacturing Corporation   Delaware
  HBP Acquisition LLC   Delaware
  BMCA Fresno LLC   Delaware
  BMCA Fresno II LLC   Delaware
GAF Leatherback Corp.    Delaware
GAF Materials Corporation (Canada)   Delaware
GAF Premium Products Inc.    Delaware
  Wind Gap Real Property Acquisition Corp.    Delaware
GAF Real Properties, Inc.    Delaware
GAFTECH Corporation   Delaware
LL Building Products Inc.    Delaware
  Ductwork Manufacturing Corporation   Delaware
Pequannock Valley Claim Service Company, Inc.    Delaware
South Ponca Realty Corp.    Delaware

(1)
Elk Group, Inc. 1% General Partner and NELPA, Inc. 99% Limited Partner.



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BUILDING MATERIALS CORPORATION OF AMERICA LIST OF SUBSIDIARIES