Do you need an acoustic floor base for your vinyl floors? It depends on the type of floor finish you're using and the local building codes. Generally, felt, cork, or foam are good acoustic underlayment options. Hush II, a patented subfloor system composed of cork and foam, can achieve between 50 and 70 IIC when combined with compatible resilient flooring products. Rubber is not recommended as it can stain vinyl flooring.
If the finished floor is installed loose, the base can also be installed loose. The selection of floor accessories, including subfloors, transition strips and adhesives, is secondary to the selection of the flooring product itself. A quality soundproofed subfloor is essential in multi-family homes to meet code requirements. When choosing an acoustic subfloor, consider factors such as moisture resistance, performance and long-term value.
Make sure it's compatible with your floor covering, adhesive and subfloor covering. Not all underlying decals are created the same way, so you can't assume that a 5 mm underlay works the same as another.