DUPONT 1/4" FANFOLD BACKER 200sf

DuPont™ Fanfold Backer Board (1/4" x 4' x 50') | 200 sq. ft.

The Ultimate Lightweight Surface Protector and Siding Underlayment

Upgrade your next exterior project with the DuPont™ Fanfold Backer. Designed for efficiency and durability, this 1/4" thick extruded polystyrene (XPS) foam board provides a smooth, level surface for new siding applications while offering an extra layer of protection for your home’s envelope.

Whether you are residing an older home or looking for a high-quality leveling board, this fanfold backer is the professional's choice for a flatter, more attractive finish.

Key Features & Benefits

Superior Leveling: Smooths out irregularities in existing siding or masonry, providing a flat "true" surface for the installation of vinyl, fiber cement, or engineered wood siding.

Moisture Management: Built-in water resistance helps protect the wall assembly from moisture infiltration, reducing the risk of rot and mold.

Easy Installation: The unique fanfold design allows for quick unfolding and rapid coverage. It cuts easily with a utility knife—no specialized power tools required.

Lightweight & Durable: Easy to maneuver on ladders and scaffolding, yet tough enough to withstand the rigors of a busy job site.

Enhanced Energy Efficiency: Provides a continuous layer of insulation that helps break thermal bridges, improving the overall R-value of your exterior walls.

Product Specifications

Why Choose DuPont Fanfold?

Unlike individual sheets, the fanfold design significantly reduces the number of seams in your underlayment, which minimizes air leakage and speeds up labor time. It’s the perfect solution for contractors looking to provide a high-end, "flat wall" look for their clients without the weight of traditional plywood or OSB backers.

Pro Tip: For maximum energy efficiency and air sealing, tape the seams of the fanfold board using a high-quality flashing tape.