The frequency of sanding and refinishing hardwood floors depends on the level of wear and tear they experience. Typically, hardwood floors should be refinished every 7 to 10 years, but this can vary. In New Jersey, factors such as high foot traffic, the presence of pets, and seasonal humidity changes can accelerate wear. It's important to monitor the finish for signs of significant wear, such as deep scratches, fading, and loss of sheen. If the floors start to show these signs earlier, it might be necessary to refinish sooner to protect the wood.