Removing mastic or other adhesive from a floor after linoleum, tile or carpet has been razed is a tedious, labor-intensive job. Using a multi-step approach will make the job a little easier and slightly less stressful.
Step 1: Use a flat-nose shovel or long-handled scraper to remove as much of the old flooring as possible. If you have access to an electric reciprocating saw, Simple Man Products markets 4-inch and 6-inch scraper blades that can make the demolition process a little easier. For large jobs, a heavy electric tile stripper might be helpful. Contact your local hardware store or rental yard for details.
Step 2: Once the majority of floor covering has been removed, it is time to tackle the adhesive residue. Many types of mastic are water-soluble. Begin by carefully pouring some boiling water onto a small section of the adhesive residue. Allow the water to soak in for a few minutes and then use a flat wood chisel to scrape away the loose mastic.
Step 3: Pour a little more boiling water onto the same spot and scrape again with a rigid putty knife, followed by a single edge razor.
Step 4: Continue working in small areas until you have cleared away as much mastic as possible.
Step 5: Mastic that does not soften with boiling water will need to be removed with a chemical adhesive remover. Adhesive removers are very caustic. Keep the area well-ventilated and wear chemical resistant gloves, protective eyewear and a respirator.
Step 6: Apply the remover liberally to a small area and wait 15 minutes or more, depending on the manufacturer’s instructions. Scrape the loosened mastic away and apply additional remover as needed.
Step 7: After you have a 2-foot-square area cleared, wash the floor with warm, soapy water and move on to the next section.
Step 8: Continue working in 2-foot square sections until the floor is virtually clear of all adhesive residue.
Step 9: Once the floor has completely dried, sand away any stubborn stains or remaining patches of mastic with a pumice stone or carbide rubbing brick. Both of these items are available at your local hardware store.
If all goes well, you should be able to lay new flooring or refinish the existing floor in no time flat.