What is the maximum allowed distance from the finished floor to the center of the tee serving a clothes washer?

The maximum allowed distance from the finished floor to the center of the tee serving a clothes washer is indeed 18 inches. This regulation is designed to ensure that the washer is properly connected to the drainage system by providing an adequate vertical drop for wastewater. Maintaining this distance helps to prevent issues with siphoning and ensures efficient drainage, minimizing the risk of overflow or inadequate drainage. Compliance with this standard is critical for the proper functioning of the appliance and to adhere to plumbing codes that safeguard against potential plumbing problems.