Hardboard siding is a composite wood product made from tightly compressed wood fibers. Many homeowners who used this product during the late 20th century experienced problems such as swelling, warping or twisting. These problems resulted in a series of class action suits in the last 1990s and early 21st century. Homeowners who still have failing hardboard siding on their homes can look for special identifying features to help them determine the type of hardboard they are dealing with. This information can be useful for class action or warranty claims or for those looking to match and repair existing siding.
How to Identify Hardboard Siding Type
Things You'll Need
Go into your attic and look for unfinished walls where you can access the back of the siding. You may need to peel away tar paper or building paper from the back of the siding boards. If there are no exposed boards in your attic, try crawl spaces, garages or mechanical rooms to look for exposed boards.
Remove one of the damaged boards if you can't access the back of the siding from inside the house. Put on your safety glasses and use a pry bar or hammer to lift a damaged siding board about an inch away from the house. You may also need to lift the board above slightly. Hold the boards in the position with your pry bar, then use a reciprocating saw to remove any nails holding the damaged board in place. Once all nails are removed, gently pry the board off of the wall.
Inspect the back of the board to see if the manufacturer's name is printed there. Some of the largest hardboard siding manufacturers include Masonite, Weyerhauser, ABTCo/Abitibi and Louisiana Pacific (LP). For a list of some other common manufacturers, refer to the website in Resources below.
Look for and identifying series of numbers and letters. If no manufacturer's name is listed, any codes printed on the back may help you identify the manufacturer. The American Hardboard Association uses codes, all starting with AHA, that corresponded to specific manufacturing facilities and brand names. For example, AHA02 corresponds with Weyerhauser siding produced in Broken Bow, Oklahoma. For a complete list of AHA codes, see the link in Resources.
Examine the texture of the board. Each hardboard manufacturer used a slightly different texture and coloring for their product, which can be used as a last-resort method of identifying the brand. According to "Homeowners Against Deficient Dwellings (HADD)," Masonite has a distinct waffle iron texture while Weyerhauser has a smooth finish that is has a color and finish similar to cork. ABTCo/Abitibi siding has a rough waffle iron finish that is similar to Masonite, but has its own distinct pattern. LP siding looks like plywood, and is made of pressed wood chips. For pictures and more identifying details, see the HADD link in Resources.
Ask your builder, your neighbors or your realtor if they can help identify your siding. Builders and realtors may have records that can help with identification. Your neighbors may have the same siding as you, especially if your homes were built at the same time, or by the same company. If all else fails, consult a siding contractor to inspect your siding and help with identification.
Masonite is a single brand of hardboard siding that was once among the most widely used (it is no longer produced). Unfortunately, many people still use "masonite" as a general term for all hardboard siding. Don't assume your hardboard siding is Masonite unless it features some of that brands identifying characteristics.