Karli S. Anderson - Feb 22, 2023 Form 4 Insider Report for Summit Materials, Inc. (SUM)

Role: Title: EVP, Chief People and ESG Officer and Head of Communications
Signature: /s/ Christopher B. Gaskill, as Attorney-in-Fact
Stock symbol: SUM
Transactions as of: Feb 22, 2023
Transactions value $: $0
Form type: 4
Date filed: 2/24/2023, 05:10 PM
Previous filing: Sep 6, 2022
Next filing: Mar 1, 2023

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	+9.22K		$0.00	9.22K	Feb 22, 2023	Class A Common Stock	9.22K		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, 2024.

Remarks:

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