Construction company Ply Gem has priced its initial public offering and gone public. The company sold about 15.8 million shares for $21 per share on the NYSE under the symbol PGEM. Controlling shareholder CI Capital Partners will retain about 70% ownership of the company on a fully diluted basis. Based in Cary, NC, Ply Gem manufactures exterior building products like siding, windows, doors, fences, rails, gutters and veneers. PGEM shares closed at $23.30 on their first day of trading.