How to Remove Underlayment Glued to Subfloor

Removing underlayment that is glued to a subfloor can be a challenging and labor-intensive task, but with the right tools and techniques, it can be done effectively. Whether you are preparing for a new flooring installation or repairing a damaged section, understanding the steps required to properly remove the glued underlayment will save time and ensure a smoother process. This guide will provide you with how to remove underlayment glued to subfloor.

What is Underlayment?

Underlayment is a thin layer of material that is installed between the subfloor and the finished flooring. It serves several key purposes, including providing a smooth and even surface, offering sound reduction, and improving insulation. Depending on the type of flooring being installed, underlayment can be made from materials such as foam, cork, felt, or plywood. For example, laminate or engineered wood flooring often requires underlayment to reduce noise and protect against moisture. Understanding the purpose and type of underlayment in your flooring system is essential when planning for its removal or replacement.

Reasons for Removing Glued Underlayment

There are several reasons why you might need to remove glued underlayment from a subfloor. One common reason is to prepare the surface for new flooring installation. Old underlayment can become worn, uneven, or damaged, making it unsuitable for laying new materials on top. Additionally, glued underlayment may trap moisture or mold, which can compromise the integrity of the subfloor and create unhealthy living conditions. Removing the old underlayment ensures that you start with a clean and stable foundation, which is essential for the longevity and appearance of the new flooring. Lastly, structural repairs or updates to the subfloor may require the removal of the glued underlayment to address any underlying issues effectively.

10 Methods How to Remove Underlayment Glued to Subfloor

1. Using a Floor Scraper

One of the most common and effective methods for removing glued underlayment is using a heavy-duty floor scraper. Floor scrapers are designed to break the bond between the underlayment and subfloor by lifting and scraping off the material. Begin by loosening the edge of the underlayment with a hammer and a chisel or pry bar. Once there is enough space, insert the floor scraper underneath the edge and push it forward to separate the underlayment from the subfloor. This method works well for thin underlayment materials and is ideal for smaller areas. However, it requires physical effort and may take some time, especially if the glue is particularly strong.

2. Applying Heat with a Heat Gun

If the underlayment adhesive is proving difficult to remove with manual tools, applying heat can help soften the glue, making it easier to lift the material. Start by setting a heat gun to a medium-high setting and holding it a few inches above the underlayment. Move the heat gun back and forth across the surface to heat the glue evenly. As the glue softens, use a floor scraper or putty knife to gently lift the underlayment from the subfloor. Be cautious when using a heat gun, as excessive heat can damage the subfloor or cause burns if mishandled. This method is most effective for adhesives that respond to heat and is ideal for smaller sections of underlayment.

3. Using an Adhesive Remover

For stubborn glue that doesn’t respond to scraping or heat, adhesive removers can be a game-changer. These chemical solutions are specifically designed to break down adhesive bonds, making it easier to remove underlayment from the subfloor. To use an adhesive remover, apply it liberally to the glued area according to the manufacturer’s instructions. Let it sit for the recommended amount of time—usually 15 to 30 minutes—so the solution can work its way into the adhesive. Afterward, use a scraper or putty knife to lift the underlayment off the subfloor. This method is highly effective but can involve strong chemicals, so ensure proper ventilation and wear protective gear like gloves and goggles.

4. Using a Circular Saw for Large Areas

For larger spaces, using a circular saw can help speed up the process of removing the underlayment. Set the saw blade to a depth that only cuts through the underlayment, ensuring that the blade doesn’t reach the subfloor beneath. Carefully cut the underlayment into manageable strips, making sure to keep the cuts straight. Once the underlayment is cut into sections, use a pry bar or floor scraper to remove the pieces. This method works well when the underlayment is firmly attached to the subfloor, as it can help break the bond and make it easier to remove the material in larger sections.

5. Leveraging a Pry Bar or Crowbar

A pry bar or crowbar is an essential tool for removing glued underlayment, especially when the material is firmly bonded to the subfloor. Begin by creating a small gap at the edge of the underlayment using a hammer and chisel. Once there is enough space, insert the pry bar under the edge of the underlayment and apply leverage to lift it. Work your way across the floor, gradually loosening and lifting sections of the underlayment. This method requires careful and steady force, as too much pressure could damage the subfloor. It’s a highly effective technique for thicker underlayment materials and larger areas.

6. Scraping with a Putty Knife

A putty knife can be a handy tool for scraping off smaller areas of underlayment or glue residue. After loosening the edge of the underlayment with a hammer or pry bar, use a putty knife to slide underneath the material and gently pry it up. This method works well for thin layers of underlayment or when you only need to remove small sections. Be sure to use a putty knife with a sturdy blade to prevent bending or breaking. While this method is labor-intensive, it offers precision and control when removing glue from specific spots or areas that are difficult to reach with larger tools.

7. Renting or Using a Floor Removal Machine

For extensive flooring projects, particularly in larger rooms or entire homes, renting or using a floor removal machine can significantly speed up the process. These machines are specifically designed to tackle the tough job of removing underlayment and adhesives from subfloors. They use a large blade or rotating drum to scrape up the material, leaving the subfloor clean and ready for new flooring. A floor removal machine is an ideal choice for professionals or homeowners working on large-scale renovations, as it reduces manual labor and ensures more uniform results. Keep in mind that rental machines may require a deposit, and it’s important to follow safety precautions when using them.

8. Soaking with Warm Water

In some cases, soaking the underlayment with warm water can help loosen the adhesive, particularly if the glue used is water-based. Start by using a sponge or mop to apply warm water over the glued underlayment. Allow the water to sit for 15 to 30 minutes to penetrate the adhesive. As the adhesive softens, use a floor scraper or putty knife to lift the underlayment from the subfloor. While this method is effective for certain types of adhesives, it may not work for stronger, more industrial adhesives. However, it’s a safe and non-toxic option to consider for lighter adhesive bonds.

9. Using a Scraping Blade Attachment with a Power Tool

If you have access to a power tool like a rotary sander or oscillating multi-tool, you can attach a scraping blade to make the process of removing glued underlayment quicker and less physically demanding. The oscillating multi-tool uses a high-frequency vibration that helps break the bond between the underlayment and subfloor without causing significant damage. Move the tool slowly and steadily along the edges of the underlayment, allowing the scraping blade to lift the material. This method is ideal for smaller areas and is highly effective in removing glue residue after the bulk of the underlayment has been removed.

10. Sanding the Subfloor

If all else fails, and you still have stubborn glue residue left on the subfloor, sanding can help remove it. Use a floor sander or hand sander with coarse-grit sandpaper to sand away the remaining adhesive. While this method can be messy, it’s effective for ensuring that the subfloor is completely smooth and ready for the installation of new flooring. Be careful when sanding to avoid damaging the subfloor, especially if it is made of wood or another delicate material. After sanding, clean the area thoroughly to remove any dust and debris before proceeding with the installation of your new flooring.

Conclusion

Removing glued underlayment can be a challenging task, but with the right tools, methods, and preparation, it can be accomplished efficiently. From using manual tools like pry bars and putty knives to leveraging power tools or specialized machines, there are numerous techniques to tackle both small and large projects. Always consider the type of adhesive and underlayment you are working with to choose the most effective approach. Thanks for reading, and we hope this has given you some inspiration on how to remove underlayment glued to subfloor!