New flooring is one of the best ways to add value to your home. But along with the choice of the perfect flooring comes the question, what are the best subfloor adhesive types. Does it even matter what type you use, as long as it bonds properly?

Yes it does!

I’ll cover a few key things in this article—all of which should ultimately help you to make the best decision. First, why choosing the right type for your application matters, and then what some of the best subfloor adhesive types are.

That means that whether you’ve decided on new flooring for the comfort or aesthetic value or simply the resale value, you’ll be able to make the wisest choice.

Still with me? Let’s get you the info you’re looking for!

Why Use Subfloor Adhesive

Depending on where you live, national and local building codes will dictate if you need to use subfloor adhesive. In most cases, in North America at least, code does not require adhesive. Then why go the extra expense and use it?

Here’s an interesting quote from Builder Magazine:

“Subflooring is a big source of callbacks.”

The article details the 11 most common reasons why new home builders get callbacks. One of them is squeaky subflooring. It goes on to say, “it’s crucial to use a high-quality polyurethane adhesive.”

floor adhesive and hammer
(Subfloor adhesives help make sure your subfloor isn’t squeaky.)

Have you ever lived or visited somewhere where the floor squeaked incessantly? It likely drove you crazy. So you’ll want to make sure you complete a new flooring project that will leave out annoying noise.

Why do subfloors squeak?

There are several reasons.

  • The subfloor starts to separate from the floor joists
  • Water damage
  • Solid wood subflooring. Chances are this isn’t something you’re planning to do, but if it is, be sure to choose a softwood for your subfloor. Fir is a good choice, but you need to make sure it’s less than 6 inches wide and installed on a 45-degree angle.
  • Floor joists have been spaced too far apart, likely to cut costs
  • Cheap subfloor panels can deflect, and the motion will make for a noisy floor

Let’s expand on that first point, as it’s one is one of the most important reasons to choose a good adhesive. Because you want all the components of your floor to come together in a way that provides the strongest floor. The better they are joined, the better your floor. In structural engineering, this is known as composite action.

According to Wikipedia, composite action happens when “two different materials are bound together so strongly that they act together as a single unit from a structural point of view.”

This is exactly what you want to achieve with your flooring.

As the quote from Builder Magazine above points out, it’s not just old homes and floors that suffer from this problem. Brand new homes with brand new floors can squeak as well.

This means you are in a unique position if you’re about to install new flooring. You get to choose your subfloor, your adhesive, and your flooring. With the right knowledge under your belt, you can be sure to end up with silent flooring.

Finally! You’ll be able to make that midnight stealth raid on the kitchen you’d always imagined but had never been able to pull off thanks to your noisy floor.

Isn’t Nailing or Screwing Your Subfloor Sufficient?

One of the reasons mentioned above for squeaky floors was deflection. When it comes to flooring, this type of movement is typically vertical.  When your flooring materials rub together, they create friction which in turn creates sound. In this case a squeak.

Cheap flooring materials, a bad job at assembling materials, or an uneven subfloor can all cause friction.

wood flooring
The main reason for squeaky floors is vertical deflection (i.e. boards rubbing together). Nails and screws don’t prevent this.

If you’ve simply used nails or screws and they have come loose—which defection can cause them to do—you can end up with the resulting squeaks. But if you have added a quality adhesive and completely bound everything together, you create a strong floor. You have composite action. To reiterate the above, “Two different materials are bound together so strongly that they act together as a single unit from a structural point of view.”

Best Types of Subfloor Adhesives

Before heading out and purchasing any product of your choice, be sure to check the warranty that comes with your flooring. Be sure to follow whatever guidelines they may have when it comes to adhesive. You don’t want to void your warranty.

For example, if your flooring is polyurethane-based engineered hardwood, it is critical to use a high-quality polyurethane adhesive. Otherwise, your adhesive may not stick.

There are three main types of subfloor adhesives:

  1. Solvent-based
  2. Water-based  
  3. Polyurethane-based

Each of these comes with its own set of pros and cons. And as mentioned above, installers need to be sure that whatever they use is in line with whatever your flooring manufacturer requires.

Once you’ve narrowed down the manufacturer’s expectations, you then need to decide what your own needs are. Are you looking for something that’s easy to work with? Are you more interested in long-lasting performance? Are you in a position to follow any regulations that might impact your installation?

Solvent-based Subfloor Adhesive

Solvent-based adhesives are typically in liquid form, with the liquid being oil or even a low boiling point gasoline. The liquids are heavy and viscous which makes it easier for them to dry. When they are dry, or the liquid has completely evaporated, the adhesive has fully cured, and it is set.

They can be used on all types of subflooring materials.

Due to their makeup, these are easy to work with and spread. However, safety protocols and regulations need to be followed.

Solvent-based Adhesive Pros

  • Bond strength
  • Fast bonding and drying
  • Can stand up to wide temperature ranges

Solvent-based Adhesive Cons

  • Expensive
  • Environmental implications due to the release of volatile organic compounds (VOCs)
  • Legislation on VOCs is getting tighter

Water-based Subfloor Adhesive

If you’re looking for a more environmentally friendly option, this is the choice for many people. They are low in emissions and they’re safe to install since they have no chemicals or harmful and toxic additives. They are also easy to use.

However, all those things that bring us health and environmental benefits also mean there are limitations. They may not offer the same level of performance and don’t work well with wood flooring.

Water-based Adhesive Pros

  • Environmentally friendly
  • Easy to use
  • Low emissions
  • No chemicals or harmful and toxic ingredients
  • Easy clean-up

Water-based Adhesive Cons

  • They may not offer comparable performance
  • Shouldn’t be used with solid wood floors

Urethane-based Subfloor Adhesives

This type of adhesive is often said to offer the best security between your subfloor and flooring materials. They are also referred to as moisture-cure adhesives.

Urethane-based adhesives are appropriate for a broad range of applications—more than either water or solvent-based.

This type of adhesive is made completely from solids, so they don’t need to evaporate in order to cure. Instead, they draw moisture from the air or the subfloor and congeal into a solid layer of rubber.

One of the biggest advantages of this type of subfloor adhesive is its ability to bridge defects in the subfloor.

Urethane-based Adhesive Pros

  • Easy to use
  • They cure quickly
  • Offer a superior strong bond

Urethane-based Adhesive Cons

  • Will have problems curing in too dry environments
  • Short working time
  • You need to use a solvent for clean-up

Recommendations for Each Type

Of course, there is a multitude of options to choose from in each category, but here are a few top-notch recommendations.

  • Water-based: Titebond GREENchoice
  • Solvent-based: DYNAGRIP Advanced
  • Urethane-based: AdvanTech

What to Use To Fill Gaps In A Subfloor?

What if you’re not laying a new subfloor? Perhaps your current floor has gaps that need filling. What you use is going to depend on what kind of subfloor you have. For a wood and concrete subfloor combo you need a cement-based formulation. For wood combinations, you need a patching compound made of calcium carbonate and silica quartz.

Whichever type you need, they’ll harden in a few hours.

If you have wood and are looking to do some spot filling, a product like Fix-It-All is probably the most appropriate.

Conclusion

Whether you’re repairing an old subfloor or putting down brand new flooring, there are a lot of options when it comes to the adhesive you choose.

Ultimately, what you use may already be decided for you if you want to keep your warranty in good standing. For example, you wouldn’t use a water-based adhesive for wood floors. Past that, you’re probably looking at personal preferences. What’s more important to you? A healthier, greener environment or performance? Only you can answer that.

Thanks for reading. Hopefully, you’ve found the information you’re looking for. Why not browse the related articles below and see if there is anything else we can help you with!