In operation for more than 40 years, Custom Building Products is an architectural design and consulting firm. It provides installation services for interior and exterior floors, bathtub walls and countertops. The firm offers a range of surface preparation products, such as backer boards, underlayment, membranes and moisture barriers. Custom Building Products also provides mortars, additives, tile adhesives, grouts, ceramic tiles, caulks, sealers and cleaners. It offers maintenance, quality control and documentation services. The firm is headquartered in Seal Beach, Calif.