Male contractor performing hardwood floor installation over glue.

What Are the Layers of Hardwood Floor Installation?

Hardwood floors have a long history as one of the most durable and attractive flooring options available. A well-cared-for hardwood floor can last a lifetime, but to get there, there are some things to think about. The durability and life span will depend on several factors, such as the type and quality of the finish, the periodic maintenance, and most importantly, the supporting structures of the hardwood floor.

In terms of the finish and maintenance, the average homeowner can expect to have their hardwood flooring refinished every 10 years or so, depending on the quality and durability of the initial finish itself. Regular maintenance will keep that finish in proper working condition, which, in turn, protects the hardwood flooring beneath. So just what is the flooring beneath? Let’s get back to our original question: what are the layers of hardwood flooring?

Essentially, there are four layers to a hardwood floor installation: joists, subfloor, underlayment, and decorative floor covering. Sounds easy, right? It probably is if you’re a professional that has the knowledge and expertise that can be found at Wall2Wall Hardwood. We have the experience and equipment to handle the job, despite whatever challenges may arise. So let’s take a closer look at the four layers.

1. Joists

Joists are essentially the dimensional lumber used to create the foundation of the floor. The joists are strategically spaced across the desired span and fashioned to create the most supportive framing necessary to hold the weight of the flooring over the duration.

Traditionally, joists were made from wood. Common types include pine, fir, hemlock, spruce, and redwood. Today, additional options include steel or engineered wood. Steel is mostly used for office buildings, apartment complexes, and large spaces that may have to support substantial weight. It’s important to consult with state and local building code administrators to make sure you’re following all the current guidelines and regulations, and a professional installer will have the ability to navigate the legal details.

While solid wood and steel joists may have more specified applications, manufacturers have created a plethora of engineered wood options that can address virtually all of the other hardwood floor installation requirements.

Engineered joists may have some features that are appealing to property owners and, according to the American Plywood Association, should also include ratings for quality, performance, and fire protection. Engineered wood is often light but incredibly strong and durable. Technically, the only flooring installation that may not require joists would be a cement floor, however, even then it might be beneficial to your decorative flooring choice.

It’s a complicated task to calculate the flooring joist framing. You need to determine the right size and composition of the joist, choose the right spacing for the span, and ensure that the potential load is fully supported. The joist support is the bottom-most layer, but it cannot function without the next layer, the subfloor.

2. Subfloor

The subfloor is the floor beneath the “floor.” It’s the layer that is directly above and fastened to the joists, which then becomes the complete foundation for the underlayment and decorative flooring (layers three and four). It is generally plywood, composite wood, or concrete. In the case of plywood or composite wood sheeting, the best practice is to arrange the largest continuous sheets available in a staggered pattern with spacing to allow for natural flex. It’s important to avoid a four-corner meeting to reduce the potential for weakness or buckling. The subfloor bears significant wear and tear over years, moisture being the most damaging. Moisture can swell, warp, degrade, and rot a subfloor in very little time.

Sagging, warping, squeaking, or a funky odor are all good signs that you may have a serious problem underfoot. Subfloors are important, so it’s a good idea to get any issues resolved as soon as you can. The longer it goes unaddressed, the more significant the damage may be to the other layers.

3. Underlayment

The third layer is the underlayment. It’s an exceptional situation for a hardwood floor installation not to include the underlayment. Underlayment for hardwood flooring is usually cork, rubber, or a cork-rubber composite. Be aware that there are additional underlayment options. In fact, underlayment can be any number of materials from felt or foam to concrete, depending on the decorative flooring to be laid above. Your flooring professional can help you decide what underlayment is best for your installation.

Having the appropriate underlayment is important for a few reasons. First, this layer provides extra stability to the decorative flooring above. It also smooths out some of the imperfections of the subfloor below it. For the homeowner, the right underlayment will provide some sound reduction, and it will add moisture protection preventing spillage from becoming seepage. Finally, the appropriate underlayment will protect and extend the life of the entire hardwood floor installation.

4. Decorative Hardwood

This is the layer that represents your entire project: the decorative, durable, and personal aspect of your flooring that you have been anticipating. There are several decisions that you must make when picking your decorative layer, and the choices are numerous.

There are two types of hardwood flooring, solid wood or engineered wood, and the choice is entirely personal because each has benefits and drawbacks. Wall2Wall Hardwoods has experienced professionals who can walk you through the specifics and make sure you have the information to make a confident decision.

To give you an idea of some of the complexity, a solid wood layer is often one of five species: cherry, maple, walnut, hickory, and oak. Solid hardwood installation is usually the traditional plank style, nailed, and finished. Each wood option will have its own ratings and properties.

Engineered wood can be manufactured to an assortment of characteristics, and a variety of installation methods giving you a lot of great options. There are manufactured wood systems that are fabricated with an integrated underlayment material, those made for floating installation, others designed for “click-systems.” The options are robust, so having a guide can help reduce the stress and uncertainty associated with such an important decision. Contact us to get started on your dream floor today. Wall2Wall Hardwoods is here to help get you there.