The terms “hardboard siding” and “pressboard siding” refer to any type of home siding that is made by mixing wood fiber with waxes, glue, fillers or resins and then compressing the mixture so it has the appearance of natural wood.

The goal was to create a product that was consistent throughout and was attractive, easy to install, easy to paint, and durable. In life, three out of four isn’t bad. Here, it can be a problem. These products proved to be less durable than anticipated, especially if installed incorrectly or if used in wet climates.

Potential Problems

There are several manufactures of this type of product, many of which are involved in or have settled class action lawsuits.

Hardboard siding started to show problems in areas of the country where the climate is wet. Among those homes affected in Alpharetta, the most common problems are:

• Swelling along the edges
• Swelling around the nails
• Bowing or waves in the siding
• Discoloration or wax bleed
• Coming apart or soft to the touch
• Fungus and mold growth

Once the siding starts to soak up moisture, it is difficult and sometimes impossible to stop the deterioration. The bottom edge of the siding starts to split and makes it easier for more water to penetrate, creating a self-perpetuating problem. Sometimes if you catch it early enough you can caulk the edges and have them hand painted.

Maintenance

Maintaining hardboard siding is critical:

• Paint it at least every five years (hand paint the edges if necessary)
• Check and re-caulked seams
• Check the nail holes to make sure they are caulked properly
• Keep you gutters clean and functioning properly
• Do not let sprinklers continually spray the siding

Jeff’s Note: Most painters spray exterior paint. Usually, this means the underside edge isn’t properly protected. It will cost more to have the edges painted by hand, but doing so will ensure the edges aren’t missed and the siding will be protected where it is most vunerable.