There are many reasons why glue may be present on a concrete surface. Carpet is often glued to concrete, as are other forms of flooring. Cabinets, wallpaper and other decorations may also be glued to concrete. Removing this adhesive is necessary before the concrete can be stained with a colored stain. If you do not remove the adhesive, the stain will not stick to the floor and it will have an uneven, unsightly appearance. Removing the glue takes a few harsh chemicals, but with proper application methods, the removal process is safe and effective.
Sweep the floor to remove all surface dust and debris. Scrape as much glue as you can off the floor using a large scraper. Wear rubber gloves, eye protection and a dust mask to protect your eyes, lungs and skin while removing the glue from the concrete floor.
Apply a liquid mastic remover on the concrete areas that still have glue stuck to the surface. Allow the liquid to sit on the floor for at least 30 minutes.
Scrape away the glue residue with the scraper. Mop the floor with floor cleaner to remove any remaining mastic remover.
Create a paste mixture of hydrated lime and denatured alcohol that has a thickness similar to toothpaste. Spread this paste liberally over any remaining adhesive. Allow it to dry completely.
Remove the dried paste with a stiff-bristled brush. This will pull away any remaining glue residue from the surface of the concrete, and some residue from inside the pores of the concrete. This is one of the most effective ways to remove all signs of adhesive from a concrete floor. Vacuum up the paste particles using wet-dry shop vacuum.
Clean the entire concrete floor with a wash of trisodium phosphate. Rinse the TSP thoroughly with a mop and clean water.
Vacuum the floor to dry it. Vacuuming will remove any remaining dirt or adhesive residue from the concrete, and make the stain adhere firmly and more evenly to the concrete surface.