For wood floors, underlayment can be more than just padding, and understanding the features that offer benefits beyond cushioning can enable installers to recommend the best fit for their customers.
First, consider the factors that play into your choice of underlayment: the type of floor (solid, engineered, or floating) and the performance goals for the underlayment as part of the floor assembly.
The composition and characteristics of underlayment vary widely. Going beyond the basics, underlayment can include: sound abatement and reduction in sound transmission between floors; insulating qualities; compression resistance; the ability to smooth minor floor imperfections; moisture protection; and the ability to be installed over radiant heat. (Some underlayment actually incorporates radiant heating elements, eliminating an installation step). Also, some underlayment is made from environmentally safe recycled materials.
There are jobs where you may want to take advantage of multiple attributes. For example, for an installation where a new floor is replacing old vinyl asbestos tile, it can be helpful to have underlayment with adequate compression resistance to properly support the floor while dispersing the impact energy of each footfall (lessening strain on knee and hip joints), and you also may want it to minimize small floor imperfections. As long as the VAT is secure, using this type of underlayment can eliminate the need for a potentially hazardous tear-out that could release dangerous fibers into the air. Or, the same type of underlayment can be glued directly over secure old vinyl composition tile, offering a smooth surface ready for the finish flooring without having to first remove the old tile and prepare the underlying subfloor.
Sound absorbing, or acoustic, underlayment quiets impact sound and inhibits noise from traveling into the room below. Acoustic underlayment is available in various materials, including polyethylene or polystyrene film, cork, rubber, and fiber, and some acoustic underlayment enables engineered wood to sound more like solid wood. In multi-family housing units, acoustic underlayment must at least meet local code; exceeding the code can go further to help prevent complaints.
Some underlayment has insulating properties. Insulating underlayment with an R-value of at least 0.50 acts as a thermal break, helping keep a room warmer in the winter and cooler in the summer.
Under engineered wood, underlayment with moisture management reduces the possibility of mold growth under the finished wood floor and can prevent subfloor or incidental perimeter moisture from marring the floor.
For floor installations that are part of green building projects, eco-friendly underlayment without VOCs can be an easy upsell. You’ll want to choose underlayment that is third-party-certified for low emissions and is also manufactured substantially or totally from recycled fibers. Incorporating this type of underlayment may enable the flooring assembly to contribute to earning LEED credits.
Electric radiant heat underlayment for under floating wood flooring can distribute quiet, clean hypoallergenic electric heat evenly throughout a room, providing supplement heating overall. This type of underlayment can also be adhered to the floor for glue-down wood.
The next time you have a job that requires underlayment, make sure you and your customer are getting the most out of it.
Reprinted from NWFA