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Moisture-Related Problems with Engineered Wood Siding

June 2002 

A ToolBase TechNote

Engineered wood sidings are made from various combinations of wood veneers, fibers or flakes, bound together with glues, resins, and/or waxes. Plywood, oriented strand board (OSB), and hardboard are basic engineered wood siding materials. Several different types and brands of engineered wood siding have experienced moisture-related failures due to product or installation defects, or improper maintenance.


  • Look for names, logos, etc. on the back side of the siding. It may be possible to see the back without removing the siding in places such as unfinished garages or attics. If siding is removed, it is best to remove a full-length piece to ensure that any markings printed on the back will be found.
  • Contact manufacturers or settlement claims websites/call centers for information on particular identifying characteristics.
  • Obtain The Siding Book: A Field Manual for Identification of Composite Siding and Damage by Siding Solutions, Inc. (see Resources).
  • Consult a home builder, siding installer, building materials or siding supplier, home inspector, and/or siding consultant such as Siding Solutions, Inc.
  • Manufacturers or others may be of greater assistance if you can provide them with any or all of the following information:
    • Siding material: plywood, hardboard, OSB
    • Siding type: lap (horizontal boards) or panel (typically start as 4 ft. x 8 or 4 ft. x 9 ft. sheets)
    • Front-side texture/pattern: smooth v. textured (e.g., wood grain, saw texture, etc.)
    • Back-side texture/pattern: smooth v. screen or waffle pattern
    • Logos
    • Manufacturing plant and/or association codes: e.g., AHA ##, where ## is a plant number.

      According to the American Hardboard Association, the following codes are in current use to identify the manufacturer or mill:

      • AHA01 Boise Cascade Corp. - Int'l Falls, MN
      • AHA02 Weyerhaeuser Co. - Broken Bow, OK
      • AHA03 Temple - Diboll, TX
      • AHA04 LP - Roaring River, NC
      • AHA05 Forestex – Forest Grove, OR
      • AHA06 Masonite – Laurel, MS
      • AHA07 Georgia-Pacific Corp. – Catawba, SC
      • AHA08 Masonite – Ukiah, CA
      • AHA09 Evanite Corp. – Corvallis, OR
      • AHA10 Weyerhaeuser Co. – Klamath Falls, OR
      • A11 Mac Millian Bloedel – North Bay, Ontario
      • AHA12 Masonite –Towanda, PA
      • AHA13 Not Used
      • AHA14 Not Used
      • AHA15 Not Used
      • AHA16 Not Used
      • AHA17 Not Used
      • AHA18 Not Used
      • AHA19 Not Used
      • AHA20 Collins Products – Klamath Falls, OR
      • LWP01 Georgia-Pacific Corp. – Jarratt, VA
      • LWP02 Georgia-Pacific Corp. - Coos Bay, OR


Class action lawsuits (national- and state-level) have been filed against several manufacturers. Settlements have been reached in some cases; others are pending or have been dismissed. Contact manufacturers, your state's Attorney General's office, and the Defective Hardboard Siding Information Center (see Resources) for up-to-date information regarding legal actions.

Manufacturers/products having reached final legal settlements:

  • Louisiana-Pacific
    Inner-Seal brand of OSB (oriented strand board). Lap and panel products (earlier known as Waferwood). A claim for damages can be filed until January 1, 2003.
    Claims phone: 800-245-2722.

  • Masonite
    Lap and panel hardboard siding products; available in various external textures designed to resemble conventional lumber products. Typically identified by a stamp with the name "Masonite" and/or the number "X90". Final Settlement approval was granted on January 15, 1998, in the lawsuit known as Naef v. Masonite. The Settlement provides a program for eligible claimants to recover the costs associated with damage caused by the installation and incorporation of Masonite Hardboard Siding. If you own Masonite Hardboard Siding installed on a home or other structure between January 1, 1980 and December 31, 1989, you must file your claim(s) by January 15, 2005. If you own Masonite Hardboard Siding installed on a home or other structure between January 1, 1990 and January 15, 1998, you must file your claim(s) by January 15, 2008.
    Claims phone: 800-330-2722

Manufacturers/products with pending or ongoing lawsuits or preliminary settlements:

  • Georgia-Pacific
    Jarratt and Catawba hardboard lap or panel siding. A settlement, which has been preliminarily approved by the court, still must receive final court approval (as of 8/18/98).
    Claims phone: 888-882-5246.

  • Masonite
    Omni-Wood OSB-based siding. Lap or panel siding, or trim product. On August 7, 1998, a settlement was granted preliminary approval. A final hearing was set for January 6, 1999. You must file by December 20, 1998, in order to be excluded from the settlement.
    Call 800-256-6990 for more information.

  • ABTCo (Abitibi/Abitibi-Price)
    Hardboard siding manufactured by ABTCo is the subject of one or more class action suits. The law firm handling the case in Alabama (potentially a national class action) is Ezell & Sharbrough, 407 Conti Street, Mobile, AL 36602.
    Phone: 334-432-1413
    Fax: 334-432-5297.

  • Jefferson Smurfit Corporation
    Cladwood siding product. Following information quoted directly from the Defective Hardboard Siding Information Center website visited October 2, 1998:
    "Jefferson Smurfit Corporation and Smurfit Newsprint Corporation, its wholly owned subsidiary ('SNC'), have been served in a purported class action entitled Carolyn Cave-Woods, et. ano. v. Jefferson Smurfit Corporation, et al, No. 97-2-19958-ISEA (Washington Superior Court) alleging negligence, unfair trade practices and breach of express warranty regarding SNC's Cladwood siding product. On April 17, 1998, the Court in this case denied the plaintiff's motion seeking to certify a nationwide class, but did certify a class of all persons who own or have owned buildings in Washington and Oregon with Cladwood siding. The Company and SNC intend to seek discretionary review of the Court's class certification ruling and to defend the action vigorously."
  • Weyerhaeuser
    Hardboard siding. State-level class actions exist in many states.


  • Composite Panel Association
    18922 Premiere Ct, Gaithersburg MD 20879
    Phone 301-670-0604, Fax 301-840-1252

  • Siding Solutions, Inc.
    3535 SW Multnomah Blvd., Suite #104, Portland, Oregon 97219
    Phone 503-244-6610 Fax 503-452-0653
    Consultant and publisher of: The Siding Book: A Field Manual for Identification of Composite Siding and Damage