The flooring in bathrooms are infamous for becoming damaged by water, and the space beneath the bathtub is not an exception to this rule. Once you have gained access to it, replacing the subfloor under the bathtub, which is often made of plywood fastened over floor joists, is a task that may be considered to be one of the less scary aspects of flooring repairs. Before work can begin replacing the flooring, the bathtub in its entirety must first be removed. Tubs made of cast iron or ceramic may weigh several hundred pounds, making it necessary to have help while removing them from the bathroom. Before removing the tub, make sure the main water valve to the house is turned off. If you do not know where the water main is located, you should get in touch with the local water agency.