Almost all types of flooring require underlayment (a.k.a. underlay) to hide subfloor imperfections, block moisture damage, and absorb noise. This thin layer of material (usually fiber, felt, rubber or foam) is sandwiched between other materials.
Choosing the right type of underlay is key to your floor’s performance and longevity, but each flooring type has its own requirements. For example, foam underlayment with a vapour barrier is ideal for laminate flooring, whereas cork underlayment with stain-resisting properties is perfect for vinyl floors.
How to Choose the Best Underlayment for Your Floor
Properly selecting and installing underlayment is important for your floor’s appearance, longevity and performance. But each type is appropriate for a different style of flooring. While some cushion and reduce pressure on our feet, legs and backs, others are made to absorb sound and stop it from travelling to the next room. The type of underlayment you choose should be based on your flooring type, surroundings and personal preferences.
1. Tile Flooring Underlayment
Tiles are a popular flooring choice for bathrooms, entryways, or any high-traffic area where a water-resistant surface is required. Tile underlayment must provide good support, so tiles and grout won’t crack when walked upon. It must also be flexible enough to absorb movement and any expansion or contraction that results from sudden temperature or humidity changes. Two underlayment materials that meet these requirements are Cement Board Underlayment (CBU) and Uncoupling Membrane.
Cement board makes for a stiff, flat layer that’s effective against water damage. It also resists movement in the subfloor to help avoid cracking in the tiles. Although most types of underlayment typically float on the subfloor, the cement board is glued to wood subflooring using thin-set tile adhesive before being screwed to the subfloor.
Uncoupling membrane, made from polyethylene, features a unique design and grid structure with square cavities, with the base of each cavity being larger than the top. This allows for easy movement and expansion/contraction while blocking the transfer of stress, which normally cracks grout and tile. It also acts as an excellent barrier to moisture and vapour, which is beneficial for wood or concrete floors.
2. Laminate Flooring Underlayment
Laminate flooring can be laid down on almost any subfloor with minimal preparation. However, since these floors float rather than being glued to the subfloor, choosing the right underlayment is a must. It lends stability to the flooring, reduces noise, and helps the floor planks stay locked together. Many styles of high-quality laminate flooring have underlayment included in their construction. In case your product doesn’t have a preinstalled underlay, you’ll need to buy one to cover minor subfloor imperfections and give the laminate greater stability.
Foam is the most common laminate flooring underlay.
There are two types:
i) Combination laminate underlay with an included moisture/vapour barrier, and
ii) Foam with no barrier.
Choose the combination variety when installing laminate flooring in the basement, bathroom, or any other high humidity area. Upgraded foam underlayment includes rubber or fibers for better durability. It also helps reduce the amount of noise that passes through the floor from one room to another.
Typically made from felt or cork, acoustic underlayment is designed to absorb sound so it doesn’t transfer to nearby rooms. Most types also have a moisture barrier so you don’t have to worry about damp-induced damages like cupping, peeling, and warping.
3. Hardwood Flooring Underlayment
A wide range of flooring comes under the heading of hardwood. This includes solid hardwood flooring such as oak, maple, hickory, ash, and exotic varieties like koa, teak, sakura or Brazilian cherry wood. It also covers engineered flooring with a top layer of solid hardwood and layers of composite material beneath. We’ll also add in cork and bamboo since the underlay options are the same as for hardwood.
The most common hardwood flooring underlayment is felt, which offers decent resistance to moisture, but a moisture barrier should also be installed in extremely humid areas.
Cork underlayment is another good choice. It provides more underfoot cushioning and sound dampening than felt and retains heat quite well when paired with radiant in-floor heating systems.
Rubber offers more insulation, sound absorption and cushioning than felt or cork. It’s typically available in rolls and can be easily cut to size and trimmed for a perfect fit. Installation is a breeze (no gluing is required), and that saves time and hassle if removal is ever necessary.
|PRO TIP: Cork isn’t entirely moisture-proof, so when used as underlayment in humid areas like basements or bathrooms, install it over a sheet of plastic. This will work as the main moisture barrier.|
4. Vinyl Underlayment
The most recommended underlayment option for vinyl floors is plywood.
When you look at your vinyl subfloor, it may appear that it’s already made from plywood, suggesting that you don’t need any underlayment. But subflooring is different from the underlayment.
While subfloors are usually made from oriented strand board (OSB) and other multilayered products constructed for strength and durability, this underlayment creates a smooth, uniform surface to lay down your flooring. Plywood underlay sheets are readily available at your local hardware store. Since vinyl is mostly waterproof, you won’t need to install a moisture barrier with your underlayment.
There are plenty of options when it comes to flooring underlayment. However, each has unique characteristics best suited to specific types of floorings. Always read the manufacturer’s recommendations and consult a flooring professional before making your final choice. If you’re still not sure what underlayment to choose for your floors, consult a flooring expert.