Owens Corning (OC -8.33%) has agreed to acquire door marker Masonite International (DOOR 34.69%) for a substantial premium to where Masonite has been trading. Investors are celebrating their good fortune, with shares of Masonite up 35% as of 12:30 p.m. ET on Friday.A new platform for growthOwens Corning is a maker of a range of building and construction materials, including roofing, insulation, and composites. In Masonite, a maker of interior and exterior doors, Owens Corning sees an opportunity to expand i ...