Louisiana-Pacific's (LP) 1990s Inner-Seal siding failed due to moisture absorption and rotting, triggering a massive class-action lawsuit. LP completely re-engineered the material in 1997 into LP SmartSide, utilizing zinc borate and robust resins that make today's engineered wood product durable and reliable.

 

 

The 1990s LP Inner-Seal Failure & Lawsuit

• The Defect: Made of pressed wood chips (OSB), the old Inner-Seal product lacked proper moisture defense. When exposed to rain or humidity, edges and nail holes wicked water, causing the boards to swell, delaminate, and rot (frequently growing mold or mushrooms). 

• The Lawsuit: Widespread premature failure led to massive litigation. Louisiana-Pacific paid out hundreds of millions in claims before the class-action settlement officially closed in 2002.

​​

​

LP Siding Today: SmartSide

• The Redesign: Released in 1997, LP SmartSide fixed past vulnerabilities by completely changing the chemical makeup of the composite.

• SmartGuard Treatment: Wood strands are thoroughly coated with zinc borate to resist fungal decay and termites.

• Advanced Resins: High-strength resins and waxes are used during pressing to lock out water, preventing the swelling and edge-checking that plagued 90s homes.