Rosenberg Building Supply Inc. Rosenberg Building Supply Inc. 15345 Highway 17 (located just west of intersection of Highway 17 and Basswood Lake/Sowerby Rds., at Sowerby) Thessalon, ON P0R 1L0 Telephone – 705-842-2303 Fax – 705-842-0792 E-mail: rosenbergbsi@gmail.com Contact – John Tremelling or Stacey Seabrook Hours of Operation – Monday to Friday 8:00 a.m. – 5:00 p.m.; Saturday 8:00 a.m. – 12:00 p.m.