How to Remove Old Glue from Subflooring

man on his hands and knees working on a floor
  • 3-4 hours
  • Beginner
  • 0-150
What You'll Need
Floor scraper
Wet/Dry vacuum
Dishwashing soap

When you want to remove or replace carpet or tile sheets on your subflooring, you will most likely find a nasty trace of glue residue once they are removed. This will make it almost impossible to lay down new carpet or tile correctly. You need to remove the glue residue in order to replace your flooring. The surface of the subfloor must first be smoothed out to make the new flooring adhere correctly. Here are the steps to follow.

Step 1 - Scrape the Glue

Scrape the glue using a floor scraper. Do this by firmly holding the scraper by its handle and attacking the glue at an angle. Use a forward-downward motion to get as much adhesive as possible off the subflooring. Use short and swift strokes in order to apply some force in removing the stubborn glue. By doing this, most of the glue should come off and flakes of it will now be lying free on the subfloor. Do this to the entire surface to remove the majority of the glue.

Step 2 - Clean the Removed Glue

Use the wet/dry vacuum to get all of the glue that you were able to scrape off. Be sure not to miss any spots on the surface so you can get everything into the vacuum. Do a systematic approach, vacuuming in straight and overlapping lines. Do another pass of the surface of the subflooring just to make sure.

Step 3 - Soak Leftover Glue

At this point, you will still see some portions of glue that would not come off with the scraper. In order to loosen them from their bond to the subflooring, drench them in a solution of warm water and dishwashing soap. In order to make the solution, mix about ½ cup of soap to a pail of warm water and mix it well. Pour the solution onto the glue sections and make sure that the entire surface is covered with it, especially the parts with the most glue residue. Let the glue soak and soften.

Step 4 - Clean Leftover Glue

Once the glue has softened, it will now be easier to scrape off and most, if not all of it, should come off the subflooring at this point. Use the vacuum again to clean the glue that has been freed. Make sure that your vacuum is capable of taking in wet debris since an ordinary vacuum will get damaged if it sucks in wet components.

Step 5 - Do Finishing Touches

There will still be some sticky remnants of the glue that can make the surface rough and finely uneven. In order to smooth out these rough patches, get fine sandpaper and sand the portions of stubborn glue that wouldn’t come off. Be careful not to sand too much as you may damage your subflooring (especially if it’s wood) and you could create an uneven surface.

Now, your subfloor is as good as new and ready to receive your new flooring.