Concrete Subfloors

• Concrete subfloors are acceptable for most laminate floors, although not all. The moisture from concrete can interfere with laminate flooring and cause warping or other issues. When laying your laminate floor over concrete, perform moisture and pH tests before to make sure the moisture level isn't too high. The manufacturer of your laminate floor will have moisture and pH level requirements. Also check the slab to make sure it's level. A subfloor that is not level will cause problems with your floor. For high spots in concrete, grind them down with a sander or grinder. Cover all vents prior to grinding to prevent concrete dust from blowing throughout your home or building. Use a floor leveling product on low spots. You may also have to wait to lay floors on newer concrete slabs to allow the water in the concrete to dry fully.
  
  

Wood Subfloors

• Plywood subfloors are often the ideal choice for installing various types of finished floors, including laminate. Depending on the manufacturer, the plywood subfloor may need to be raised and not just laying on a concrete subfloor. As with concrete, a plywood subfloor still needs to be leveled and structurally sound. Remove any damaged sections of the wood subfloor and replace them if need be. You may need to check the moisture level of the wood subfloors as well.
  
  

Other

• In many cases, you can install laminate flooring over existing floors such as tile, laminate, linoleum, bamboo, hardwood, porous stone or vinyl. If you have these types of existing floors, it is sometimes better to leave them under the laminate instead of ripping them up. Before installing glue-down laminate over a pre-existing floor, remove all residues, paints, oils, wax or adhesives.
  
  

Underlayment

• Underlayment is typically either foam or cork and sits between the laminate and subfloor. In addition to underlayment, a moisture barrier may also be required. When choosing the underlayment, follow the manufacturer's recommendations. A certain thickness, material type or other factor may be required depending on your laminate brand.