Choosing The Best Underlayment for Hardwood Flooring

By Samuel N •  Updated: 02/25/23 • 

When installing solid hardwood flooring, underlayment is essential and offers several benefits. An underlayment can provide a smooth and flat surface, act as a moisture barrier, and insulation, reduce noise, and much more. Different types of underlayments are in the market, making it harder to choose one. You are in the right place if you’re looking for different types of underlayment to lay your oak, maple, hickory, or other types of hardwood flooring.

I’ll help you choose the best underlayment for your hardwood floors in this post. Below are some factors to help you select an underlayment for your hardwood flooring. Enjoy.

Underlayment Materials Available

Felt Underlayment

Felt is the most common type of underlayment used under hardwood flooring. Although new types of underlayment are in the market, felt has proved to be a dependable, time-tested flooring for hardwood floors. Felt is dense, and although it’s not waterproof, it slows down moisture transfer from the subfloor to the hardwood floor. If you live in a high-humidity area, you might have to look at other underlayment options.

3mm Felt Underlayment

3mm Felt Underlayment

Felt underlayment is great when used over a wood subfloor/substrate. However, it is not recommended for use over concrete. It is easy to install felt underlayment, and staples are the most common way to fasten it to the subfloor. Feeling underlayment is a great option to check out if you’re working on a budget. It’s easy to install, has basic soundproofing and moisture protection, and is created from recycled materials.

Cork Underlayment

Cork has gained popularity because it is an eco-friendly product. For homeowners who prefer ‘green products,’ cork is natural and renewable. Although slightly more expensive than felt underlayment, cork provides a cushioning effect and excellent soundproofing. Cork is also a natural insulator that will help regulate your floor’s temperature during cold winter.

Cork Underlayment Installed in The Kitchen

Cork Underlayment Installed in The Kitchen

Anti-microbial properties in cork also mean you’ll worry less about pests, mold, and mildew. Because it is a porous material, cork will not offer better moisture protection than an underlayment like rubber. However, it can be treated for moisture protection, or you can use a plastic sheet for moisture protection in humid conditions.

Foam Underlayment

Foam is one of the cheapest and easiest underlayments to install. Like cork underlayment, foam also provides excellent sound insulation and adds flexibility to the hardwood flooring. Usually, foam flooring comes with an extra layer on one side that acts as moisture protection. There is also upgraded foam underlayment that includes rubber or other materials to increase its density, durability, and moisture resistance.

Installing Distressed Hardwood Flooring on Foam Underlayment

Installing Distressed Hardwood Flooring on Foam Underlayment

Rubber Underlayment

Rubber is another underlayment you can use under your hardwood flooring. It has excellent moisture resistance and better soundproofing than foam, felt, or cork. It’s also easier to install because of its pliability and flexibility. However, rubber is slightly more expensive to buy than other types of underlayment.

Rubber Underlayment on OSB Subfloor

Rubber Underlayment on OSB Subfloor

Consider the Hardwood Species

Not every hardwood flooring is created equally. This means there is no single underlayment that works for every wood flooring species. Each will require a different underlayment for better comfort, installation, durability, and maintenance.

For example, softer hardwood floorings, like cherry and walnut, will need to be reinforced with a thicker and more durable underlayment like rubber. On the other hand, harder hardwood floorings like hickory, Brazilian teak, and maple can do with just felt or foam underlayment. Harder hardwood floorings can also handle slight changes in humidity, eliminating the need for a moisture/vapor barrier. However, this does not mean installing hardwood flooring in high-humidity areas without proper protection.

The Condition of the Subfloor

Evaluating the subfloor’s condition is also something to consider when choosing the proper underlayment for your hardwood floors. Take note of the subfloor’s material and its condition. A flexible underlayment will work best if the subfloor is slightly uneven or damaged. This is because a flexible underlayment will allow it to take imperfections, leaving a good surface for hardwood installation.

If the subfloor material is plywood or some wood, then you’ll need to protect them against moisture. However, you also need to let them breathe to avoid trapping moisture and causing the material to rot. A semi-permeable underlayment, like felt, is great because it will allow the wood to breathe while offering some level of protection against moisture. Semi-permeable underlayments are rated between 0.7 and 2.9.

For concrete subflooring, you want to keep moisture from going through the underlayment to the hardwood floor. Choose an impermeable underlayment rated 0.15 or lower to stop moisture in its tracks. This will keep moisture below the underlayment, avoiding hardwood floor problems like buckling, warping, or peaking.

Are You Planning to Install Radiant Heating?

If you want to install radiant heating under your hardwood floor, you’ll need to be more selective when choosing an underlayment. Because radiant heating produces heat, you want to skip on underlayments like felt that have asphalt because they generate unpleasant odors. Radiant heating can also cause condensation, so you should choose an underlayment that can handle vapor/moisture without compromising its integrity.

The insulation value of the underlayment should also be considered. For radiant heating, you should select an underlayment with a lower R-Value. The R-value stands for resistance, which determines the capacity of an insulating material to resist conducting heat. A good underlayment, with a lower R-value, is much more effective in letting heat penetrate through to the floors.

Samuel N

Samuel N is the founder of Improve Floor and has been in the flooring industry since 2005. Since then, his mission has been to make flooring easier for everyone. He helps countless people with flooring installation, finishing, maintenance, and repairs each year.