Brief Overview of the Importance of Installing a Subfloor on Concrete

When it comes to home upgrades, flooring installation projects can seem daunting. This is especially true when installing a subfloor on concrete. Homeowners sometimes overlook this vital step, drawn in by the charm and warmth of wood flooring. But failure to properly install a subfloor can have serious consequences, from moisture damage to compromised structural integrity. Properly installed subfloors over concrete not only safeguard the durability of your flooring but also contribute to the comfort and aesthetic of your home.

Introduction to California Flooring & Design and Their Expertise in Flooring Installation

At California Flooring and Design, we understand how crucial it is to get this first layer right. With years of expertise in installing wood subfloors over concrete, we make it our business to ensure your flooring stands the test of time. Our team of in-house experts stays on top of the latest installation techniques to provide you the kind of quality that you expect and deserve.

Main Information Takeaways:
Installing a subfloor on concrete is the vital first step when laying down a new floor.
– It protects your floor from moisture damage and increases its durability.
– California Flooring & Design, with years of expertise, ensures a sturdy and safe installation.

Infographic on the importance of correctly installing a subfloor on concrete - installing subfloor on concrete infographic step-infographic-4-steps

Understanding the Basics of Subfloor Installation

A subfloor serves as the canvas we work on when installing a new floor. It’s the unsung hero of any flooring project, providing support and stability for your chosen flooring material. But before we dive into the nitty-gritty of installing a subfloor on concrete, it’s crucial to understand what a subfloor is and why a dry, clean, and flat surface is so important.

What is a Subfloor and Why is it Important?

A subfloor is a structural layer of material laid directly on top of the floor joists. Its purpose is twofold: to provide a stable and level surface for the finished flooring and to protect it from moisture coming up from the concrete slab. A well-installed subfloor can significantly extend the lifespan of your finished flooring, be it carpet, hardwood, or laminate.

The Importance of a Dry, Clean, and Flat Surface

When installing a subfloor on concrete, having a dry, clean, and flat surface is paramount. Concrete slabs can often be uneven and have high moisture levels, which can damage your finished flooring over time.

Getting the concrete surface dry, clean, and flat is a process that involves leveling the surface, sealing it to prevent moisture damage, and making sure it’s clean of any debris. If the concrete slab hasn’t dried properly, moisture-related problems with your flooring are almost guaranteed.

Types of Subflooring and Their Costs

There are several types of subflooring you can choose from, each with its unique advantages and costs. The most common types are plywood and oriented strand board (OSB). Plywood is known for its strength and stability, while OSB is a more cost-effective alternative that still offers good performance.

The cost of subfloor replacement typically ranges from about $3 to $10 per square foot. This can vary based on labor costs and the type of subflooring you choose. However, remember that a well-installed subfloor will pay for itself many times over by extending the life of your finished floor and preventing costly repairs down the line.

At California Flooring and Design, we’re experts in ensuring the subfloor is perfectly prepared for the specific type of flooring you choose. We believe in doing the job right the first time, so you can enjoy your beautiful new floor for many years to come, backed by our 5-year guarantee.

Preparing the Concrete for Subfloor Installation

When it comes to installing a subfloor on concrete, proper preparation of the concrete surface is crucial. The integrity of your new floor depends on the concrete being clean, dry, and level. Let’s dive into why these steps are important and how you can accomplish them.

Surface Leveling: The Foundation of a Great Floor

A level surface is essential for a successful flooring installation. Any dips, bumps, or unevenness in the concrete can lead to problems down the line, such as popping or cracking in the wood floor.

To level your concrete, you may need to use a concrete grinder or a self-leveling compound. If you’re unsure about the process, don’t hesitate to reach out to us at California Flooring and Design. We have the expertise to ensure your concrete is perfectly level before installing your new floor.

Plywood Installation: Overcoming the Challenges

Securing plywood to concrete can be tricky. While it’s a common method for installing a subfloor on concrete, things can go wrong if not done correctly. The plywood needs to be adequately secured to prevent movement that could damage your new floor.

Using mechanical systems such as powder load or pneumatic pressure nail guns is recommended for securing the plywood. Remember, the plywood should be at least 5/8” thick to ensure stability and durability.

Preparing Your Concrete: Cleanliness is Key

Before installing the subfloor, it’s essential to clean the concrete thoroughly. Remove any existing adhesive, paint, or other substances that could interfere with the installation. Make sure the concrete is completely dry before you start installing the subfloor, as moisture can cause serious problems in the future.

In addition, it’s essential to conduct accurate moisture testing. The best indicator is Relative Humidity (RH) testing. If the concrete slab has not been dried properly, moisture issues with wood flooring applications are almost guaranteed.

At California Flooring and Design, we can help you navigate these preparation steps. Our team of professionals are trained in properly preparing concrete surfaces and installing subfloors. With our assistance, you can be confident that your new floor will be installed correctly, giving it the best possible start to a long life.

So, whether you’re looking to install a floated, glue-down, nail-down or screed system subfloor, remember that proper preparation is the key to a successful installation. And remember, all our installations are backed by our solid 5-year guarantee, giving you peace of mind that your investment is protected.

Methods of Installing Subfloor on Concrete

Understanding the methods of installing subfloor on concrete is crucial to ensure a successful flooring installation. Each method has its unique process and guidelines. Here’s an overview of the most common methods: floated, glue-down, nail-down, and screed system subfloors.

Installing a Floated Subfloor

A floated subfloor is often recommended for above-grade applications. In some cases, such as on-grade and below-grade installations, a vapor retarder is necessary.

Construction worker installing subfloor - installing subfloor on concrete

To install a floated subfloor:

  1. Begin by placing a layer of plywood subfloor panels parallel to the wall, using a ¾” spacer between the plywood and the wall, and a 1/8” spacer between panels.
  2. Lay a second layer of plywood at a 45-degree angle to the first layer.
  3. Staple or glue the two plywood layers to one another using a 12” interior grid pattern, taking care not to puncture the vapor retarder.

Installing a Glue-Down Subfloor

A glue-down subfloor also requires a vapor retarder when installing ¾” wood flooring over concrete.

To install a glue-down subfloor:

  1. Cut your plywood panels into 2’x8’ or 4’x4’ sections.
  2. Score the panels to a depth of half their thickness using a 12” x 12” grid.
  3. Apply an approved adhesive and lay the plywood sections in a staggered joint pattern, with 1/8” spacers between sheets and ¾” spacers at walls.

Installing a Nail-Down Subfloor

For nail-down subfloors, a moisture-control vapor retarder is recommended.

To install a nail-down subfloor:

  1. Stagger panel joints and use 1/8” spacers between panels.
  2. Use ¾” spacers against walls.
  3. Fasten the subfloor using a mechanical system such as a powder load or pneumatic pressure nail gun.

Installing a Screed System Subfloor

For engineered wood flooring less than ¾” thick and solid plank flooring 4” or wider, it’s necessary to overlay a plywood over the screed system. More details for installing over screeds can be found here.

At California Flooring and Design, we’re experts in all these methods and can help you choose the best one for your specific needs. Remember, proper installation is key to a long-lasting floor, and we’re here to ensure that happens.

Tips and Tricks for Successful Subfloor Installation

In our years of experience at California Flooring and Design, we’ve gathered a wealth of knowledge when it comes to installing subfloor on concrete. Here are some handy tips to make the process go smoothly.

Follow Adhesive Manufacturer’s Recommendations

Adhesive plays a key role in keeping your subfloor stable. It’s vital to follow the manufacturer’s instructions. This includes the correct application technique, the right type of adhesive to use, and the proper trowel notch and spread rate. If not adhered to, it can lead to subpar results and potential damage to your flooring down the line.

Use a Vapor Retarder in Certain Installations

A vapor retarder is an essential component when installing subfloor on concrete, especially in on-grade and below-grade applications. This layer prevents moisture from seeping up into the hardwood, which can cause warping, rotting, and other forms of damage. It’s recommended anytime solid ¾” wood flooring is installed over concrete and required for installation over concrete with a high moisture reading.

Apply Underlayment Properly

The underlayment is another critical element. It offers several benefits such as sound absorption, moisture damage prevention, and thermal insulation. Whether it’s cork, foam, or plywood, the underlayment acts as a shock absorber, protecting the hardwood from potential damages and increasing its longevity. Remember, it’s important to apply it correctly to reap these benefits.

Install Engineered Wood Flooring Over Screeds

When it comes to engineered wood flooring, screeds can be a great option. The screeds provide a flat and stable base for the flooring to rest on, especially on a concrete subfloor. But, as with all methods, proper installation is key. Make sure the screeds are firmly secured to the concrete and are level before laying the flooring.

In conclusion, installing a subfloor over concrete might seem daunting, but with these tips, the process can be made a lot easier. And remember, we’re here at California Flooring and Design to guide you every step of the way, ensuring a successful installation and a floor that you’ll love for years to come.


In the journey of installing a subfloor on concrete, we’ve navigated through a lot of critical information. Let’s take a moment to bring everything together.

Subfloor installation is the critical foundation to your new floor. It’s what makes your floor stable, comfortable, and long-lasting. There are several methods to consider for installation, including direct gluing, floating, nail-down, and screed systems, each with its unique benefits and considerations.

Regardless of the method you choose, always keep in mind the vital role of a vapor retarder in maintaining the longevity of your floor, especially when dealing with concrete subfloors. This is particularly important if your concrete has a high moisture reading, as it can lead to significant issues over time.

At California Flooring and Design, we understand that the process of installing a subfloor on concrete can seem complex. But remember, you’re not alone in this. We are here to provide you with expert advice and professional services to ensure successful installation.

Our commitment to quality and customer satisfaction is reflected in our 5-year guarantee on our products. It’s our way of assuring you that we stand by our products and services. We believe in the importance of peace of mind when it comes to your home’s flooring, and we strive to deliver that to every customer.

Remember, a well-installed subfloor is the foundation of a beautiful, durable, and comfortable floor. And we’re here to help you achieve just that.

Thank you for trusting California Flooring and Design with your flooring needs. We look forward to serving you and helping you create the perfect floor for your home.

beautiful hardwood floor - installing subfloor on concrete