Beacon Roofing Supply, Inc. (NASDAQ:BECN) has announced the commencement of an underwritten secondary public offering of 5 million shares of its common stock by CD&R Boulder Holdings, L.P., an entity affiliated with Clayton, Dubilier & Rice, LLC. Morgan Stanley is the sole underwriter in the offering. The selling stockholder will receive all net proceeds and will continue to hold over 10 million shares of Beacon common stock after the offering. No shares are being sold by Beacon, and the total number of Beacon's shares outstanding will not change as a result of the offering.