What should be done prior to installing flooring over an existing floor?

Prior to installing flooring over an existing floor, it is essential to properly clean and level the surface. This process ensures that the new flooring has a stable, smooth, and even base, which is crucial for both aesthetic appearance and functional performance. A clean surface helps to guarantee effective adhesion if using glued flooring materials, preventing issues like bubbling or lifting. Additionally, leveling addresses any irregularities that could lead to problems such as stress on the new flooring, creaking, or cracking over time.

While installing insulation, applying a waterproof barrier, and reinforcing floor joists may be important considerations in certain scenarios, they are not prerequisites for every flooring installation. Insulation might be necessary if there is a significant gap between the subfloor and the crawl space, but this is not universally required. Similarly, a waterproof barrier is essential in areas prone to moisture but not for every installation. Reinforcement of floor joists typically applies to situations where the existing structure is inadequate to support the weight of the new flooring, which is an uncommon issue in most installations. Therefore, focusing on cleaning and leveling is the fundamental step before proceeding with any new flooring project.