Summit Materials this afternoon completed an add-on offering of senior notes through bookrunners Bank of America, Citi, Barclays, UBS, Credit Suisse, Deutsche Bank, and Blackstone, according to sources. Terms on the deal, which was upsized by $50 million, were finalized at the tight end of talk. The original $250 million dates to January 2012 issuance at par, which was also tight to talk, also after a small upsizing amid heavy interest. It was the aggregates company’s market debut, and proceeds from the bond deal, along with those from a $400 million term loan, were used to refinance existing debt. In this return to market after two years, Summit Materials seeks capital to fund an acquisition. Indeed, proceeds from today’s execution support the acquisitions of Alleyton Resource, a sand and gravel company, and Colorado Gulf, a cargo-transport-services concern. The purchase is approximately $179 million, and additional proceeds from the bond sale back related special payments, some RC repayment, and general corporate purposes, sources noted. Terms: