Selecting the right subfloor material and leveling a subfloor are crucial yet often overlooked aspects of flooring installation that lay the groundwork for your entire project. The subfloor is the foundational layer that sits directly beneath your visible flooring, serving both structural and functional purposes. Choosing the correct subflooring material is essential not only for the stability and longevity of your floor but also for enhancing its overall performance in terms of strength, moisture resistance, and sound insulation.

This blog aims to provide you with comprehensive insights into how to choose the most suitable materials, emphasizing the importance of leveling for optimal durability and effectiveness.

 

Types of Subflooring Material:

1. Plywood:

Plywood is a popular subflooring material known for its strength and stability. It is made from multiple layers of wood veneers, glued and pressed together to form a solid sheet. This cross-laminated structure minimizes expansion and shrinkage, providing a durable and stable base for flooring materials. Plywood is also easy to install and works well with a variety of flooring types, including hardwood, laminate, and tile.

  • Properties: Plywood is made from multiple layers of wood veneers glued together in alternating directions. This cross-graining method increases the material’s strength and stability, reducing expansion and shrinkage.
  • Benefits: It’s known for its excellent structural integrity and resistance to warping and sagging. Plywood is also easy to install and relatively affordable, making it a popular choice among homeowners.
  • Ideal Usage: Best used in dry areas away from moisture-prone zones like basements or bathrooms unless properly sealed with a moisture barrier.

 

2. Oriented Strand Board (OSB):

Oriented Strand Board (OSB) is another common subfloor material, similar in usage to plywood but generally more cost-effective. It consists of compressed layers of wood strands coated with adhesive and arranged in specific orientations for added strength. OSB provides good resistance to moisture and is particularly suited for use under carpet and vinyl flooring. However, it can swell if exposed to excessive moisture, so proper sealing is recommended in damp areas.

  • Properties: OSB is composed of pressed wood strands coated with adhesive. The strands are oriented in layers, with each successive layer’s strands running perpendicular to the previous, adding strength.
  • Benefits: OSB typically offers a higher load-bearing capacity than plywood and is usually less expensive. It also has good uniformity and dimensional stability.
  • Ideal Usage: OSB performs well in dry to moderately moist environments and under most types of flooring, but it should be avoided in places where it can be exposed to a lot of water.

 

3. Concrete:

Concrete subfloors are extremely durable and offer excellent longevity, making them an ideal choice for both residential and commercial buildings. They provide a very stable base for any type of floor covering and are particularly popular in buildings where a moisture barrier is necessary, such as in basements or areas with high humidity. Concrete is also fire-resistant and helps in soundproofing, though it can be hard underfoot and cold without proper insulation.

  • Properties: Concrete is a mixture of cement, water, sand, and gravel. It hardens into a stone-like material that is extremely tough and durable.
  • Benefits: Concrete is resistant to fire, moisture, rot, and pests, making it one of the most durable subfloor options available.
  • Ideal Usage: Ideal for ground-level installations where moisture might be a concern, such as basements, garages, and areas with radiant heating systems.

 

4. Cement Board:

Cement board is a robust subfloor material commonly used under ceramic tile or stone due to its resistance to moisture and mold. It is made from cement and reinforcing fibers, which provide an excellent substrate that is not prone to warping or deterioration in wet environments. Cement boards need to be properly installed and secured with mortar and screws, but once in place, they offer a very stable and durable surface.

  • Properties: Cement board is a combination of cement and reinforcing fibers formed into sheets. It is very tough and resistant to moisture.
  • Benefits: This material is particularly resistant to mold and moisture, making it excellent for use in bathrooms, kitchens, and other high-moisture areas.
  • Ideal Usage: Often used as a backing for tiled walls and floors because it provides a very stable, durable surface that won’t warp or deteriorate in the presence of water.

 

5. Particle Board:

Particle board is made from compressed wood chips and resin, making it the least expensive subfloor option. While it is easy to install and provides a smooth surface, it is less durable and moisture-resistant than other subfloor materials. Particle board is generally used in dry, low-traffic areas and is not recommended for use under tile or in any area where it might be exposed to moisture, as it can swell and deteriorate quickly.

  • Properties: Particle board is engineered from wood chips, sawmill shavings, or even sawdust, and a synthetic resin or other binder, which are pressed and extruded.
  • Benefits: It is one of the most cost-effective subfloor options and provides a smooth surface.
  • Ideal Usage: Best suited for interior applications in dry conditions. Due to its susceptibility to moisture damage, it should not be used where there is a high risk of water exposure.

 

How Does the Choice of Subflooring Material Affect the Installation Process:

Compatibility with Flooring Type:

  • The subfloor material needs to be compatible with the specific requirements of the finished flooring, such as weight-bearing capacity, moisture resistance, and installation method (nail, glue, or float).
  • For example, tile and stone floors require a very stable, solid subfloor to prevent cracking, while laminate and vinyl may benefit from a slightly more forgiving subfloor.

Preparation and Installation:

  • Certain subflooring materials, like concrete, require additional preparation steps like moisture/vapor barrier installation before the finished flooring can be laid.
  • The thickness and installation method (gluing, screwing, or nailing) of the subfloor can also impact the overall installation process.

Subfloor Leveling:

  • Uneven subfloors, regardless of material, need to be properly leveled using self-leveling compounds before the finished flooring is installed.
  • This leveling process is crucial to prevent issues like squeaks, cracks, and uneven wear of the finished floor.

Fastener Requirements:

  • The type of fasteners used to secure the subfloor can affect the overall stability and performance of the finished floor, especially in preventing squeaks.
  • Some subflooring materials may require specific fasteners or installation techniques to ensure a secure, long-lasting foundation.

Existing Conditions:

  • If an existing floor is being used as the subfloor, its condition and compatibility with the new flooring must be carefully evaluated before installation.
  • Damaged or unsuitable existing subfloors may need to be completely removed and replaced.

 

By understanding how the subflooring material affects the installation process, homeowners and contractors can make informed choices to ensure a successful, long-lasting flooring project.

 

Steps for Leveling a Subfloor: Commercial and Professional Use Only

Properly leveling the subfloor is a crucial step in preparing for a successful flooring installation. Uneven or wavy subfloors can lead to a variety of issues with the finished flooring, including squeaks, cracks, and uneven wear. Here is an introductory guide to leveling a subfloor:

  1. Identifying Uneven Spots

The first step in leveling a subfloor is to carefully inspect the surface and identify any low spots or high points. This can be done using a straightedge, spirit level, or laser level to detect areas that are not flat.

  1. Applying Self-Leveling Compound

Once the problem areas have been located, a self-leveling compound can be used to create a smooth, level surface. These specialized products are designed to flow and spread evenly across the subfloor.

  1. Preparing the Subfloor

Before applying the self-leveling compound, it’s important to properly prepare the subfloor. This may involve cleaning the surface, priming it, and ensuring any cracks or holes are filled.

  1. Establishing Reference Points

To help guide the application of the self-leveling compound, it can be helpful to drive screws or nails into the subfloor at the high points. These reference points can then be used to ensure the compound is poured to the correct depth.

  1. Pouring and Spreading

The self-leveling compound should be mixed according to the manufacturer’s instructions and then poured onto the subfloor. A long-handled squeegee or trowel can be used to spread the compound evenly and flush with the reference points.

  1. Allowing Proper Curing

After applying the self-leveling compound, it’s crucial to allow the proper curing time before installing the finished flooring. This can range from 24 to 48 hours, depending on the product.

By carefully leveling the subfloor using these techniques, homeowners can help ensure a smooth, stable foundation for their new flooring, preventing future issues and ensuring a long-lasting installation.

A square resting on concrete subflooring material displays that leveling a subfloor is successful.

 

Get Professional Help from East Coast Flooring & Interiors

The selection of subflooring material and leveling a subfloor are critical steps in the flooring installation and renovation process. These foundational aspects significantly influence the durability, appearance, and overall performance of your new floor.

 

At East Coast Flooring and Interiors, our team of professionals possesses the expertise and precision necessary to guarantee that these crucial preparatory steps are handled correctly, ensuring a flawless finish. To avoid potential issues and to achieve the best results for your investment, we invite you to contact us today. Let East Coast Flooring and Interiors elevate your space with the assurance of quality and craftsmanship that lasts.