Do Hardwood Floors Need Underlayment?

When you decide to install a hardwood floor, one of the questions is whether you need an underlayment. In order to make an informed decision, first, you need to understand what an underlayment is and what purpose it serves. You should consider the advantages and if there are any disadvantages. Finally, you should consider the various types of underlayment materials out there and learn the ideal choices for hardwood floors. 

What Is An Underlayment and Why Would It Be Needed?

A typical floor in a home has several layers: the subfloor, which is part of the house structure; the underlayment, which is a layer of material that goes on top of the subfloor; and the floor covering, which is the beautiful layer that you walk on. The underlayment serves various purposes. 

- If your subfloor is not 100% level and has some imperfections, the underlayment can provide a smooth layer for your flooring so that it lies flat and does not appear uneven.

- The underlayment can serve as a sound barrier. It can dampen sounds from footsteps walking across the hardwood floor. It can reduce sounds that travel through the rooms like volume from the TV, voices, appliances, and other unwanted noises. When you need to move furniture around, the noise from the move can be significantly reduced and not annoy others in the house.

- The underlayment can also serve as a moisture barrier for your expensive hardwood flooring. Moisture can come from beneath the house and through the subfloor. If this moisture reaches the hardwood flooring, the floorboards can warp and sustain water damage. The underlayment with a vapor barrier can block this moisture from reaching the hardwood floor, thus protecting it from getting damaged from exposure to moisture.

- The underlayment can insulate your room. It can help keep your interior temperature constant by preventing exterior heat or cold from coming up through the subfloor into your living space.

So, the underlayment can improve your living environment, give your hardwood floor a smoother appearance, extra support, and protection against damage. It can extend the life of your investment. 

What type of underlayment is recommended for hardwood flooring?

Underlayment comes in different materials. It can be made from cork, rubber, foam, or felt. Although you cannot see the underlayment after your floor covering is installed, using the right underlayment will give your floor a better performance. For a hardwood floor, the recommended material is cork or foam. Here is a brief description of these two types.


Foam is inexpensive and easy to install. It provides great insulation against sound. It gives your hardwood floor a softer step. As the temperature from the different seasons makes your hardwood floor expand and contract, the foam underlayment serves to decrease the friction against the subfloor caused by this expansion and contraction. You can get a layer of foam with a built-in vapor barrier to protect your hardwood flooring from moisture.


Cork is an excellent underlayment material. The insulating properties of cork are great in keeping the temperature of the hardwood floor consistent. It is more effective in absorbing sound than the other types of underlayment material, so it is wonderful, especially for multi-level properties. It adds insulation to your house. The material provides firm support to the hardwood flooring, but it has enough flexibility to mold to the subfloor's imperfections to make your hardwood floor more stable. Cork has a natural resistance to microbes. Its anti-mcrobial properties can protect your wood flooring from bacterial agents, mold, and mildew, which is suitable for those who suffer from allergies. Cork is a natural and sustainable resource, which makes it a very environmentally friendly option. The only thing that it lacks is moisture resistance . If you choose a cork underlayment, you should get one that has a vapor barrier built-in.

Although both foam and cork are the better choices of underlayment material, foam is softer than cork, and thus makes the floor flex more when you walk on your floor. For a more solid step with less give, cork is a better choice which we recommend.

What happens if no underlayment is used?

underlayment for hardwood floors

If you do not use an underlayment beneath your hardwood floor, you may end up with a floor that is not as stable. If the subfloor is not perfectly smooth or level, your hardwood floor can warp over time. The unevenness of the subfloor will cause hardwood floorboards to shift or move without a firm layer of support beneath them. What will happen over time is that your expensive hardwood floor will wear out faster. You will end up with repairs that will add up in cost that will cost you more than if you had installed an underlayment from the start.

Is a vapor barrier needed under my wood floor?

Yes, it most definitely is required. Moisture from the exterior can wick up through the ground and up to your subfloor. If your floor does not have an underlayment, this moisture can reach your floorboards. Your hardwood floor is susceptible to warping if exposed to moisture. Over time, moisture can destroy your floor altogether. Moisture also harbors the growth of mold and mildew, which is harmful to the health of the home's occupants. The layer of underlayment can protect your floor and block moisture from reaching it, but it must have a vapor barrier installed with it. The vapor barrier will keep the moisture from reaching your hardwood floorboards.

As you can see, installing an underlayment is a smart decision when planning to install a hardwood floor. A hardwood floor is a big investment that can add value to your home. For the reasons mentioned above, an underlayment will protect your investment. It improves your living environment and extends the life of your floor. Your beautiful hardwood floor will give you many years of enjoyment if it is properly installed, supported, and maintained.