What is Louisiana-Pacific (LP) Inner-Seal Siding?

Louisiana-Pacific was hit with a barrage of lawsuits in the 1990s over the alleged subpar performance of LP’s faux-cedar Inner-Seal siding. LP Inner-Seal siding was produced from 1985-1995.

Inner-Seal siding from LP came with a 25-year warranty. However, the siding frequently started to decay, fall apart, and change color. Homeowners complained that their siding was expanding, discoloring, cracking, and even fungus and mildew was growing on it.

Inner-Seal siding was a composite wood product that was pressure-fit together. The boards of this siding were made of stacked, pressed sheets held together by adhesive. The lower lap edge of the siding would fracture, absorb water, and expand as the glue started to degrade over time. The siding became exposed to the outdoors as a result of the delamination. Homeowners found clusters of mushrooms sprouting from the panels’ undersides.

After Hurricane Andrew caused havoc in South Florida in 1992, the product’s fragility became immediately clear. The disintegration process was intensified and accelerated by the high winds that tore through the panels, exposing the underlying oriented strand board (OSB) to torrential rainfall. LP was the subject of more than 37,000 claims, which were ultimately settled for over $1 billion by the business. For its part, the business recovered during the ensuing ten years, despite the fact that LP made no admissions of guilt. LP “got the most money to the most people in the quickest amount of time,” according to the judge who oversaw the case.

If your home was built in the 1990’s or earlier, you should check to see if your home has LP siding. Step outside and inspect your siding from above. In a perfect world, there should be no gaps or fractures, but LP Inner-Seal siding will show symptoms of board fragmentation. Look for a web of cracks on the bottom lap edge of your home’s siding. Can you break off bits by brushing your thumb against the cracks? This is an indication that the OSB is starting to delaminate, which produces voids, pits, and fractures that trap moisture and result in swelling. Moisture and the development of mold or fungi are brought on by this fragmentation.

Unfortunately, if your house still has LP Inner-Seal siding, you’ll have to pay for replacement costs. Homeowners are no longer permitted to submit a claim to the LP Settlement Administrators following the conclusion of the class action litigation in 2002.

Louisiana-Pacific (LP) still makes siding products. In 1997, Louisiana-Pacific (LP) redesigned its siding and introduced LP “SmartSide.” There have been no significant claims of any problems with this new siding product.