Remove floor tile adhesive by scraping as much of the adhesive away as possible using a putty knife. After removing the easily scraped away adhesive, use a heat gun to soften any remaining hardened adhesive left on the floor. Scrape the adhesive away while applying heat until none remains.
When scraping and applying heat don't get the job done, it may be necessary to use an adhesive solvent to break down the adhesive to a point where it can then be scraped and removed. Only use tile adhesive solvent in a well-ventilated area. Tile installed in a home prior to 1984 may contain asbestos or use an adhesive glue containing asbestos fibers and should be removed by a professional to prevent health risks.