Deon MacMillan - 01 Mar 2022 Form 4 Insider Report for Summit Materials, Inc.

Role: Title: EVP, Chief People Officer and Head of Corporate Communications
Signature: /s/ Christopher B. Gaskill, as Attorney-in-Fact
Issuer symbol: N/A
Transactions as of: 01 Mar 2022
Net transactions value: $0
Form type: 4
Filing time: 03 Mar 2022, 15:21:04 UTC
Next filing: 11 Mar 2022
SEC: View on sec.gov

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	SUM	Restricted Stock Units	Award	$0	+8,420		$0.000000	8,420	01 Mar 2022	Class A Common Stock	8,420		Direct	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Each restricted stock unit represents a contingent right to receive one share of Class A common stock of the Issuer ("Class A Common Stock"). The restricted stock units will be settled in either Class A Common Stock or cash (or a combination thereof) at the discretion of the Issuer's Human Capital and Compensation Committee.
F2	These restricted stock units vest in three equal annual installments beginning on February 28, 2023.

Remarks:

Title: EVP, Chief People Officer and Head of Corporate Communications