Summit Materials appointed Karl H. Watson as new COO. Karl has more than 25 years of experience in the construction materials industry. In 2017, he served as President, Cement & Southwest Ready Mix at Martin Marietta Materials, Inc., a supplier of construction aggregates and heavy building materials. Prior to joining Martin Marietta, Karl served in various leadership positions at Cemex, S.A.B. de C.V., a Mexican cement manufacturer, including President, Cemex USA. Prior to Cemex’s acquisition of Rinker Group Ltd., an Australian building materials supplier, Karl held various executive positions at Rinker in both the United States and Australia.