Can You Attach Luan to a Concrete Floor?

Luan

• In the building trades, luan is a very lightweight plywood composed of multiple thin layers of luan, a tree native to Southeast Asia. These thin veneers are compressed into a solid, lightweight piece. Luan is easy to install, economical and is appropriate for use as an underlayment for a variety of flooring types, from carpet to resilient flooring. Resilient flooring is any hard surface floor, such as hardwood, tile or linoleum. Once luan is attached to a concrete subfloor, homeowners can install carpet or resilient flooring above it. Luan levels the floors and makes a sheer surface on which to adhere surface floors.

Types

• Luan is available in two types: exterior glue and water-resistant glue. You can identify the difference between the types by the stamp located at the bottom edge of the flooring material. Type 1 is exterior glue, and type 2 is water-resistant glue. The glue is what secures luan to a concrete floor. Since concrete is a relatively smooth subfloor, the use of luan to smooth and grade the floor isn't typically required. The decision to use luan, as an underlayment, is best determined by the material used to create the top floor.

Top Floor

• Flooring choices range from carpet to tile to hardwood. Carpets tend to mask surface problems and are forgiving of imperfections in subflooring and underlayment. Resilient flooring is not forgiving. If you're using resilient flooring, be sure to follow the manufacturer's instructions. Though luan underlayment is economical and simple to install, it may not provide the best sub-surface for tile and other resilient flooring. The highest grade of luan, BB, should be used for resilient flooring.

Considerations

• Concrete floors can be overlaid with thick plywood and then topped with a thin luan underlayment for additional coverage. Thick plywood pieces are attached to concrete subflooring with fasteners, such as cement or liquid nails. If you're using concrete nails, ensure that all driven nail heads are topped with carpenter's putty or another smooth substance. This material creates a barrier between a nail's hard surface and luan's weak surface. Nail heads that poke through underlayment will destroy surface flooring.