Form 4 - Statement of changes in beneficial ownership of securities

SEC Form 4 
   

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
	Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person* Loomes David (Last) (First) (Middle) 1801 CALIFORNIA STREET SUITE 3500 (Street) DENVER CO 80202 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol Summit Materials, Inc. [ SUM ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) See Remarks
	3. Date of Earliest Transaction (Month/Day/Year) 12/20/2024
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Class A Common Stock	12/20/2024		M		2,250	A	(1)	20,219(2)(3)	D
Class A Common Stock	12/20/2024		M		5,177	A	(1)	25,396	D
Class A Common Stock	12/20/2024		M		13,974	A	(1)	39,370	D
Class A Common Stock	12/20/2024		F		9,452	D	$50.5	29,918	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Restricted Stock Units	(4)	12/20/2024		M			2,250(5)	(6)	(6)	Class A Common Stock	2,250	$0	0	D
Restricted Stock Units	(4)	12/20/2024		M			5,177(5)	(7)	(7)	Class A Common Stock	5,177	$0	0	D
Restricted Stock Units	(4)	12/20/2024		M			13,974(5)	(8)	(8)	Class A Common Stock	13,974	$0	0	D

Explanation of Responses:

1. Reflects restricted stock units that upon vesting converted into shares of Class A common stock of the Issuer ("Class A Common Stock") on a one-for-one basis.

2. Total holdings include shares of Class A Common Stock received pursuant to a stock dividend paid on December 29, 2022.

3. Total holdings include shares of Class A Common Stock acquired through the Issuer's Employee Stock Purchase Plan on October 18, 2022, May 28, 2023, November 30, 2023 and May 31, 2024.

4. Each restricted stock unit represents a contingent right to receive one share of 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.

5. Reflects the accelerated vesting of restricted stock units for the purpose of reducing or eliminating the excise tax imposed under Sections 280G and 4999 of the Internal Revenue Code of 1986, as amended, that would be imposed on amounts payable to the Reporting Person in connection with the consummation of the transactions contemplated by the Agreement and Plan of Merger, dated as of November 24, 2024, by and among the Issuer, Quikrete Holdings, Inc. (Purchaser), and Soar Subsidiary, Inc., a wholly owned subsidiary of Purchaser.

6. These restricted stock units would otherwise vest on February 28, 2025.

7. These restricted stock units would otherwise vest in two equal annual installments on each of February 28, 2025 and February 28, 2026.

8. These restricted stock units would otherwise vest in three equal annual installments on each of February 28, 2025, February 28, 2026 and February 28, 2027.

Remarks:

Title: EVP, Cement

	/s/ Christopher B. Gaskill, as Attorney-in-Fact	12/24/2024
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

---