Article: If you’re replacing an old floor with a new one, your first task will be to get rid of the outdated flooring material. Use a pry bar to pull up hardwood floors one section at a time, or unfasten carpet or laminate and roll it up from one end. This will expose the subfloor underneath, which is where most leveling problems lie.  You can leave linoleum or sheet vinyl in place if it’s difficult to remove or if removal would damage the sub-floor. Apply bonding agent and floor leveling compound on top of the existing floor. Stripping tile can be a messy, laborious, time-consuming job. Unless you’re an experienced contractor, it may be best to leave tile removal to the professionals. To remove carpet, cut it into smaller pieces using a razor knife. Then, pull it up. If you’re installing a new floor, skip to checking the level and making a note of where the foundation should be worn down or built up. Set down a 6 ft (1.8 m) level every few feet from one end of the room to the other. This will give you an idea of how much work you’ve got cut out for you, and where it’s needed most. A good general rule of thumb is that the foundation shouldn’t slope more than 3⁄16 inch (0.48 cm) every 10 feet (3 m).  If the area is very large, use a long, straight 2 in × 4 in (5.1 cm × 10.2 cm) board and set your level on top of it. If the floor is uneven, lift up the board until it is level so you’ll know how much flooring compound you’ll need to even it out. Floors are rarely perfectly level. It’s okay if the angle is off by a fraction of an inch in either direction. Keep in mind that “flat” isn’t the same thing as “level.” Minor defects may not be noticeable to the eye, but they will be to your level. More often than not, sagging or slanted flooring materials are responsible for off-level floors. Occasionally, however, there will be humps that cause the foundation to rise above a specified height. These can be dealt with by sanding down wooden subfloors with an electric sander, or by grinding them with a motorized angle grinder. Sanding and grinding produces a lot of dust. Be sure to wear eye protection and a facemask or ventilator while wearing down uneven subflooring. Once the subflooring is exposed and free of high spots, prepare it for the new flooring by removing any remaining dust and debris. Vacuum the entire room, especially around the corners where dust particles tend to collect. Mop concrete subfloors with diluted muriatic acid to clear away traces of oil, wax, or adhesive that may be clinging to the surface.  Fill cracks in concrete subfloor and make sure the filled areas are level before cleaning the subfloor. A thorough cleaning is also necessary to get the subflooring ready to accept the liquid bonding agent. Starting with the edges of the room along the molding, spread on a thin coat with a wide, soft-bristled paintbrush. Work your way about a foot out from each wall, then use a roller or mop to apply the bonding agent to the larger area in the center.  The bonding agent will create a chemical connection with the leveling compound to help it set up more securely and last longer. Wear gloves, waders, and old clothing when working with liquid bonding agents and leveling compound. Once these materials get on something, they can be nearly impossible to get off.

What is a summary?
Remove the existing flooring. Check the level of the subflooring. Sand down high spots. Clean and repair old subflooring. Cover the subflooring with a bonding agent.