Underlayment Under Vinyl Flooring: Is It Necessary?

When it comes to installing vinyl planks, homeowners wonder if they need underlayment or not. Here is what you need to know:

You need an underlayment on the subfloor before laying vinyl planks on the floor especially if the subfloor is uneven. The purpose of the underlayment is to create a flat and sturdy base for the vinyl planks to sit on. Underlayment also protects the vinyl planks from moisture damage, mold growth, and leaks.

If there is an existing underlayment or cushioned tiled floor on the subfloor, you don’t need an underlayment. Some vinyl planks like luxury vinyl come with pre-attached underlay so you don’t need another underlayment for these vinyl planks.

This post reveals more about the underlayment requirements for vinyl flooring including a guide on different types of underlayment to use for vinyl plank flooring. Let’s dive in.

Why Does Underlayment Matter For Vinyl Plank Flooring?

An underlayment matters for different reasons for a vinyl plank floor but the main reason vinyl plank flooring needs an underlayment is for support and stability.

The underlayment gives the vinyl plank flooring extra support underneath so the vinyl floor can handle more use and weight. Without an underlayment, your vinyl plank floor will make squeaking noises and possibly crack over time since there is no support beneath the planks.

Here are other reasons underlayment matters for vinyl plank flooring:

1. To Make the Vinyl Plank Flooring Smooth and Even

Vinyl plank flooring is formed by attaching several vinyl planks side by side using the tongue and groove locking mechanism. To make the floor smooth, the planks have to be arranged and locked on an even surface.

If the subfloor is uneven or bumpy, then the planks will not be smooth. But, if you put a flat underlayment on the subfloor first, then the planks can be installed on a flat and even base making your vinyl floor smooth and even.

2. Moisture Protection

An underlayment also helps with moisture protection. Long-term exposure to water will damage your plank vinyl floor so it’s usually advised to install a waterproof underlayment before installing the vinyl planks to protect the planks from water in cases of rainfall, flood, or a leak under the subfloor.

If there is a waterproof underlay beneath your vinyl planks, then water will not reach the planks even if there is a water problem in the subfloor.

An underlayment also prevents the vinyl planks from rot and mold growth which will happen if water reaches the planks.

3. To Allow the Locks to Click in Place

As explained earlier, vinyl plank flooring is formed by connecting several planks using a tongue and groove locking mechanism between the planks.

Without an underlayment especially on a patchy subfloor, the planks will not slide in place as they should. Even if you manage to click the locks, some of the locks will be under more pressure than others which can cause some planks to separate and cause gaps in your vinyl floor.

4. Soundproofing

Vinyl plank underlayment is usually made from foam, rubber, felt, or cork padding. All of these materials are very good at soundproofing.

Using an underlayment made from any of these materials will eliminate the annoying click sound that comes from the vinyl planks when it is walked on. Soundproofing is even more important if you have neighbors living downstairs.

5. Insulation

Vinyl plank flooring can be very cold, especially during the cold winter months. An underlayment beneath the planks provides insulation and warmth so your floor feels warmer. An underlayment will also make your floor more comfortable and easier on your feet and knees.

Next, let’s find out how to know if you need underlayment for your vinyl plank flooring.

How To Know If You Need An Underlayment For Vinyl Plank Flooring

To know if you need an underlayment beneath your vinyl plank flooring or not, you’ll need to consider a few factors, especially the condition of the subfloor and the type of vinyl planks that you have.

Here is what you need to find out to know if you need an underlayment:

Were the Vinyl Planks Designed With an Underlayment?

The first thing to find out is the type of vinyl planks that you have. If the planks were designed with foam-like padding underneath each of them, then that means you have vinyl planks with pre-attached underlayment.

This type of vinyl plank doesn’t need an underlay since it has already been designed with all the support it needs. Luxury vinyl planks are known to have pre-attached underlayment.

However, if there is no underlayment beneath the vinyl planks, it means that you’ll need one on the subfloor before installing the vinyl planks.

Is the Subfloor in Good Condition?

The next thing to find out is the condition of the subfloor. Is the subfloor rough, bumpy, patchy, or uneven? In this case, you’ll need underlayment for the vinyl flooring because the subfloor is not in a good condition to carry the vinyl planks.

On the other hand, if the subfloor is smooth, flat, and strong enough to support the floor, then you can install the vinyl planks directly.

Is There an Existing Underlayment or Cushion on the Floor?

You also need to find out if there is an existing underlayment or cushion on the floor. For instance, if there was laminate flooring on the floor before, there is a chance that there will be an existing underlayment beneath the laminate floor since laminate floors are usually installed on the underlayment.

In this case, you don’t need another underlayment since there is an existing one on the subfloor. If you want to use another underlayment, you’ll need to remove the existing one first because too many underlays under your vinyl planks will not let the locks click.

Also, if there is an existing cushioned floor, you don’t need an underlayment. This is because cushioned tiles are always smooth and strong making the floor an ideal base for vinyl plank flooring. So, on a cushioned floor, you don’t need underlayment for the vinyl planks.

Do You Need Moisture Protection?

If you are installing the vinyl flooring on a bathroom floor, a kitchen floor, or the laundry room, then you’ll need moisture protection beneath the floor to prevent water from getting under the vinyl planks.

In bathrooms, kitchens, and laundry rooms, several pipes are run under the ground and walls. If any of these pipes get damaged, it can cause a water leak on the subfloor. Without an underlayment, the planks will be exposed to moisture. So, for moisture protection, you need a waterproof underlayment.

What Happens If You Don’t Put Underlayment Down Before Installing Vinyl Flooring?

If you don’t put underlayment down before installing a vinyl floor, then the vinyl plank flooring will develop problems such as lifting, buckling locks, a separation between the planks, and swelling in the middle of the floor.

These problems will arise due to a lack of proper support and moisture resistance beneath the vinyl planks.

Here is what happens when there is no underlayment beneath a vinyl floor:

The Vinyl Floor Will Be Noisy

The first problem will be the squeaking noises that come from your vinyl flooring when the floor is walked on or when you place items on the floor.

The squeaks that you hear come from the joints or locks between the planks and the squeaks tell you that there is no support beneath the vinyl flooring putting more pressure on the locks and causing the squeaks.

Asides from the squeaking noise, you’ll also hear clicking sounds every time you walk over the vinyl floor with stilettos or hard soles. The clicking sound is because there is no soundproofing beneath the vinyl planks.

Moisture Damage

If there is no waterproof underlayment beneath the vinyl planks, then the planks will be exposed to water from the subfloor in cases of flood, leaks, or loose pipe fittings below the floor.

This will cause water damage and possibly mold growth beneath the vinyl planks. This can also cause the planks to warp or swell.

The Floor Will Be Uneven

The main purpose of an underlayment is to provide a sturdy and flat base for the vinyl planks to be installed on especially if the subfloor or existing base is uneven.

If you install vinyl flooring on an uneven subfloor without using an underlayment first, the flooring will not be even.

Here are other minor problems that will occur if you don’t use an underlayment before installing vinyl planks:

  1. There will be no insulation which means the vinyl floor can get very cold in winter
  2. The vinyl flooring will not be comfy
  3. The vinyl flooring might not have enough support to withstand weight and traffic

Next, let’s check out the types of underlayment to use under a vinyl floor.

Types of Underlayment You Can Use Under Vinyl Flooring

Here are the top types of underlayment for vinyl plank flooring:

Standard or Foam Underlayment

This is the most common type of underlay for vinyl flooring. Standard underlay is gotten from a foam material. To make this underlay, the hard foam material is compressed together and or filled with air. The underlayment also comes in wraps or rolls of different sizes and thicknesses.

The biggest advantage of foam underlayment is that it is common and affordable. So, this is one underlayment you are sure to find in any store and for a cheap price too. The biggest disadvantage of this underlayment is that it is not waterproof as foam absorbs water over time.

Cork Underlayment

Cork underlayment is usually designed from cork material and this underlayment is designed to be soundproof. Cork is also a durable material meaning that it can handle traffic and weight properly. Cork underlay is also great at holding moisture.

Particleboard Underlayment

Particle underlayment is gotten from foam and wood materials. This underlay is very strong and sturdy but it’s not waterproof. Foam and wood both absorb water so don’t use this underlay in bathrooms.

Wood Underlay

This underlay is gotten from wood materials, especially plywood. The underlay is also strong and it provides good support. You should know that homeowners commonly claim that this underlay has no soundproofing.

Combination Underlayment

This underlayment is gotten by combining several materials including felt, rubber, cork, and foam. This is the hybrid of vinyl plank underlayment and it can be used on just about any type of subfloor. However, you should know that combination underlayment is expensive.

Things You Need To Know About Installing An Underlayment

You should know that the type of underlayment to use for your vinyl floor depends on:

The Type of Vinyl Planks You Have

If you have luxury vinyl planks for instance, then you’ll need thick underlayment because luxury vinyl planks are usually heavier than regular vinyl planks. Some luxury planks even have underlayment so if you have such type of vinyl planks, then you don’t need underlayment.

The Installation Method (Floating, Glue-down, Nailed-down, Etc.)

For the floating method, you’ll need an underlay that allows you to lay the planks directly on the underlayment.

For the glue-down method, you’ll need a textured underlay so the vinyl glue can stick. Also, if you want to nail the vinyl planks to the subfloor, then you’ll need an underlay that allows the nail to go through.

The Need for Moisture Resistance or Not

If you are installing the vinyl flooring on a part of your home that will experience moisture like bathrooms, then you’ll need a waterproof underlayment. You don’t need a waterproof underlayment in the bedroom or living room.

The Material of the Subfloor (For Instance, Is It a Concrete or Wood Subfloor?)

The material of your subfloor also matters. For concrete subfloors, you don’t need a thick underlay because the concrete subfloor already provides enough support. On a wood subfloor, you’ll need a thicker underlay to provide more support beneath the vinyl floor.

The Rating of the Underlayment

Vinyl plank flooring underlayment is usually rated based on soundproofing, insulation, and thickness. You should consider these ratings based on the requirements that you need from the underlayment.

How To Install Underlayment Under Vinyl Flooring?

Installing underlayment under a vinyl floor is no big deal. It’s very easy as long as you have the right underlayment and the needed tools. Here is what you’ll need to lay an underlayment under a vinyl floor:

  • A pair of scissors
  • A broom
  • Floor brush
  • A rubber mallet
  • A chisel
  • A pair of gloves

Here is a guide for installing underlayment:

  1. Remove all objects on the floor including furniture and electronics
  2. Remove the carpet or rug
  3. Use a chisel to separate and remove the baseboard trims
  4. Check the condition of the subfloor and repair any damages or dents
  5. Sweep and clean the subfloor to remove dust
  6. Measure the subfloor and use a pair of scissors to cut and adjust the underlay to size
  7. Unwrap and put the underlayment directly on the subfloor

What Is The Best Thickness For Vinyl Flooring Underlay?

The best thickness for vinyl plank floor underlay is between 2mm and 4mm. In most cases, the best thickness for a vinyl floor is 3mm.

You should know that vinyl underlayment ranges in thickness level from 1mm to 6mm with 1mm being the thinnest and 6mm being the thickest.

You should also know that when it comes to the vinyl underlayment, thicker isn’t always good. If the underlayment is too thick, the vinyl plank locks will not click. Generally, you wouldn’t need an underlayment thickness of more than 4mm for residential spaces.

Final Words

In summary, picking an underlayment is just as important as deciding on which vinyl planks to get. Underlayment makes the floor smooth and stronger.

Remember that if the vinyl planks already have pre-attached underlayment, you don’t need an extra one. Also, if there is an underlayment or cushion already on the subfloor, you don’t need another one. As an expert guide, use cork underlay for high traffic floors and a waterproof underlay for high moisture areas.

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