Summit Materials, Inc. Declares Special Stock Dividend

Summit Materials, Inc. (NYSE: SUM) (“Summit,” “Summit Materials,” "Summit Inc." or the “Company”), a leading vertically integrated construction materials company, today announced that it has declared a special stock dividend of 0.017 shares of the Company’s Class A common stock, par value $0.01 per share (“Class A Common Stock”), for each outstanding share of Class A Common Stock. The special stock dividend is payable on December 29, 2022 to stockholders of record as of the close of business on December 15, 2022. Cash will be paid in lieu of issuing any fractional shares of Class A Common Stock.

As previously disclosed, the Company’s subsidiary Summit Materials Holdings L.P. (“Summit Holdings”) makes cash distributions to the holders of Summit Holding’s limited partnership units (“LP Units”) to cover tax obligations arising from any estimated net taxable income of Summit Holdings allocable to holders of LP Units. As an LP Unit holder, the Company has received such cash distributions from Summit Holdings in excess of the amount required to satisfy the Company’s estimated tax obligations. As a result, the Company is using the excess cash of approximately $59,500,000 in the aggregate to acquire newly-issued LP Units from Summit Holdings and to make cash payments in lieu of issuing any fractional shares in connection with the related special stock dividend described above. The stock dividend has been declared in order to maintain an equal number of shares of Class A Common Stock outstanding to the LP Units held by the Company, and the aggregate number of Class A Common Stock issued in the stock dividend will equal the number of additional LP Units the Company is purchasing from Summit Holdings. The LP Units will be purchased at a per unit price of $29.94, which is the volume weighted average price per share of the Class A Common Stock for the five trading days ended December 2, 2022. Cash payments in lieu of fractional shares will also be made on the basis of a value per share of Class A Common Stock of $29.94 per share.

Stockholders are not required to take any action in order to receive the stock dividend or cash in lieu of fractional shares, and the book entry accounts of the stockholders of record will automatically be credited with the additional shares representing the stock dividend. Stockholders will be paid for the value of any fractional shares that would have been received in lieu of any such fractional shares. Where shares are held in a brokerage account, the additional shares will be distributed to the broker on the stockholder’s behalf. The stock dividend is being administered by Broadridge Corporate Issuer Solutions, Inc., the Company’s transfer agent.