What is the difference between subfloor and underlayment?

Basically, subfloors are a structural part of your home that provide strength and rigidity to your home's flooring. Underlays, on the other hand, protect your floor covering from moisture, help soundproof your floor, and offer cushioning and comfort underfoot.

Do I need underlayment and subfloor?

If your subfloor is wood and you want to put down tile, you're going to need an underlayment. As Bob Vila points out, the industry standard is a concrete backer board. A common tile installation method starts with a layer of thinset (a mortar adhesive) going over the subfloor.

What is considered the subfloor?

What Is a Subfloor? A subfloor is the solid material beneath your floor covering. It is attached to your home's floor joists and acts as a base for your finished flooring, such as carpet, hardwood, laminate, tile, etc. Typically, a subfloor is made of plywood or oriented strand board (OSB) panels.

What is the difference between a substrate and an underlayment?

Substrate - The underlying support surface upon which the flooring is directly installed. Subfloor–Underlayment Combination – Designed to meet both the structural requirements and to provide a smooth surface to receive the floor covering.

What goes over subfloor?

Underlayment: Some types of flooring can be installed directly on top of the subfloor, such as vinyl flooring. Other types need a middle layer, called underlayment, such as laminate,carpet and tile.

Subfloor VS. Underlayment Explained

What is the best material to use for a subfloor?

Plywood. Plywood is considered the most popular material used for subflooring, it has been used since the 1950s and remains one of the top choices for contractors. Standard plywood works perfectly fine as a subflooring material, but the best option is ¾” tongue-and-groove plywood subflooring.

What is considered underlayment?

Underlayment: The underlayment is the layer of flooring that sits directly under the finish floor. The underlayment is somewhat structural and sometimes optional, but it is there to provide a smooth surface on which the visible finish floor sits.

Do I need 2 layers of subfloor?

That's the usual approach. Almost no one puts down double-thick subfloor in residential applications (for cost and handling reasons), and both layers need to be fastened to joists. Only thin underlayment can be fastened just to the subfloor.

Should you put a vapor barrier between subfloor and underlayment?

Therefore, because concrete is porous, it's a good idea to install a vapor barrier over your concrete subfloor before installing your flooring. This way you can stop the vapor drive of water upward to your floors, protecting them from any damage (source).

Can you put plywood over subfloor?

Install a layer of at least ½” or preferably 5/8” ply over the existing planks. This is particularly important if your old sub floor has lumps and bumps in it. If you don't respect this thickness of ply, then you're highly likely to see rises and falls in your new flooring.

Is underlayment necessary?

Underlayment is not optional. If your laminate planks don't have it already attached, we recommend that you buy rolls of underlayment on which to install your laminate floor.

What happens if you don't put underlayment under laminate flooring?

Without underlayment to add a layer between these damp subfloors and the surface flooring, your laminate can quickly become wet, warped, and mildewy, harming its overall integrity. Moisture over time can also break down floor adhesive which causes the floor to start warping.

What flooring does not require underlayment?

If you're laying the LVP over an existing cushion-backed vinyl floor or a below-grade tile floor, then you won't need to use an underlayment. However, you'll want to use one in every other application including covering existing hardwood floors, vinyl flooring that isn't cushioned, and concrete floors.

What thickness should a subfloor be?

Subfloor sheets for both OSB and plywood come in 4 by 8 or 4 by 12 sheets. Thicknesses for products used for subfloors are generally 23/32 inch (just under 3/4 inch), but thicker sheets are available where building codes call for them.

Do you nail or screw subfloor?

Ideally, nail down your subfloor using corrosion-resistant nails that will securely hold it in place and last a long time. Screws are a great alternative that you can easily remove, but they are not as sturdy. Screws are superior in terms of reducing floor squeaks, but the installation is slower.

Is plywood or OSB better for a subfloor?

OSB has a lower resale value than plywood due to its lower strength. For this reason, few homeowners prefer OSB in their homes. Apart from costs, plywood is superior in all the other areas, such as the strength of the structure. For this reason, it's a superior material for use on the subfloor.

Do you need a moisture barrier on wood subfloor?

Do I need a vapor barrier for hardwood floors?" The answer is YES! Moisture can destroy hardwood flooring. It causes cupping, warping, and even mildew if not treated. You must install a moisture barrier to protect your flooring from water wicking up from below.

Can you use plywood for underlayment?

Recommendations aside, plywood is one of the most versatile underlayments because it will give you that nice, smooth surface needed for a flawless vinyl or carpet installation, and it works under most other products too.

Why do you need floor underlayment?

Underlay or flooring underlayment is a thin layer of material such as fiber, felt, rubber or foam. The thin layer of material helps cushion, sound absorption, insulation and reduce wear with your flooring.

What size plywood is best for subfloor?

The minimum thickness of plywood for subflooring is about 5/8 inch. Since it does not hold fasteners as well as plywood, OSB must be a little thicker, or at least 23/32 inch.

What can I use for subfloor Besides plywood?

There are four primary materials used as subfloor: plywood, oriented strand board (OSB), concrete, and high-performance panels.

Does underlayment need to be glued down?

No, you should not glue down your underlayment. Underlayment is is a floating material, the same as your laminate flooring. In most cases, you should not glue or nail your underlayment down. You should always check with the installation instructions of the underlayment for proper installation instructions first.

What kind of underlayment do I need?

The normal choice is a thin foam pad material made of polyethylene or polypropylene, which rolls out in sheets. Plywood subfloors: A breathable foam-type underlayment is generally used when installing laminate flooring over plywood or OSB subfloors.