Summit Materials Inc. Watch

from SC 13G/A 1 page Exhibit 1 Joint Filing Agreement in Accordance With Rule 13d-1 (F) Under the Securities Exchange Act of 1934, as Amended, the Undersigned Hereby Agree to the Joint Filing With All Other Reporting Entities (As Such Term Is Defined in the Schedule 13g/A) on of Each of Them of a Statement on Schedule 13g (Including Amendments Thereto) Behalf With Respect to the Class a Common Stock,$0.01 Par Value, of Summit Materials Inc., and That This Agreement Be Included as an Exhibit to Such Joint Filing. This Agreement May Be Executed in Any Number of Counterparts All of Which Taken Taken Together Shall Constitute One and the Same Instrument. in Witness Whereof, the Undersigned Hereby Execute This Agreement This 14th Day of September, 2018. Levin Capital Strategies, L.P. By:/S/ John A. Levin John A. Levin Chairman and Chief Executive Officer Levin Capital Strategies GP, LLC By: John A. Levin 2005 Grat Separation Trust, as Managing Member By: /S/ Elisabeth Levin Elisabeth Levin, Trustee Lcs, LLC By:/S/ John A. Levin John A. Levin General Partner Lcs Event Partners, LLC By:/S/ John A. Levin John A. Levin General Partner Lcs L/S, LLC By:/S/ John A. Levin John A. Levin General Partner By:/S/ John A. Levin John A. Levin

from S-1/A 36 pages Summit Materials, Inc. Class a Common Stock, Par Value $0.01 Per Share Form of Underwriting Agreement

from S-1/A 40 pages Summit Materials, Inc. Class a Common Stock, Par Value $0.01 Per Share Underwriting Agreement

from S-1 38 pages Summit Materials, Inc. Class a Common Stock, Par Value $0.01 Per Share Underwriting Agreement