Summit Materials, Inc.
Class A Common Stock, par value $0.01 per share
[ ], 2015
Citigroup Global Markets Inc.,
Goldman, Sachs & Co.
As representatives of the several Underwriters
named in Schedule I hereto,
c/o Citigroup Global Markets Inc.
388 Greenwich Street
New York, New York 10013
Goldman, Sachs & Co.
200 West Street
New York, New York 10282
Ladies and Gentlemen:
Summit Materials, Inc.,
a Delaware corporation (the "Company"), proposes, subject to the terms and conditions stated herein, to issue and sell to the several Underwriters named in Schedule I hereto (the "Underwriters"), for whom you
are acting as representatives (the "Representatives"), an aggregate of [ ] shares of the Class A common stock, par value $0.01 per
share, of the Company (the "Class A Stock") and, at the election of the Underwriters, up to [ ] additional shares of Class A Stock
of the Company. The aggregate of [ ] shares of Class A Stock to be sold by the Company are herein called the "Firm Shares" and the
aggregate of up to [ ] additional shares of Class A Stock to be sold by the Company are herein called the "Optional Shares." The Firm
Shares and the Optional Shares that the Underwriters elect to purchase pursuant to Section 2 hereof are herein collectively called the "Shares." The respective amounts of the Firm Shares to be so purchased by the several
Underwriters are set forth opposite their names on Schedule I hereto.
In connection with the offering contemplated by this
Agreement and the transactions described under, or contemplated in, the section titled "Organizational Structure" in the Pricing Prospectus (the "Reorganization Transactions"): (i) Summit Materials Holdings L.P.,
a Delaware limited partnership ("Summit"), will amend and restate its limited partnership agreement (as so amended and restated, the "Summit LP Agreement") to, among other things, (a) designate the Company
as its sole general partner and (b) modify its capital structure by eliminating its existing limited partnership interests and creating a new single class of limited partnership interests ("LP Units"); (ii) the
Company and Summit will enter into an Exchange Agreement (the "Exchange Agreement") with each holder of LP Units; (iii) the Company will enter into a tax receivable agreement (the "Tax Receivable
Agreement") with each holder of LP Units (other than the Company) on the date hereof; and (iv) the Company will enter into a registration rights agreement with each holder of LP Units (the "Registration Rights
This Agreement, the Summit LP Agreement, the Exchange Agreement, the Tax Receivable Agreement and
the Registration Rights Agreement are collectively referred to herein as the "Transaction Documents."
1. In this
Section 1, references to the Companys knowledge, belief or awareness shall mean the knowledge, belief or awareness of each of the Company and Summit. Each of the Company and Summit, jointly and severally, represents and warrants
to, and agrees with, each of the Underwriters that:
(a) A registration statement on Form S1 (File
No. 333-[ ]) (the "Initial Registration Statement") in respect of the Shares has been filed with the Securities and Exchange Commission (the
"Commission"); the Initial Registration Statement and any post-effective amendment thereto, each in the form heretofore delivered to the Representatives and to the Representatives for each of the other Underwriters, excluding
exhibits thereto, have been declared effective by the Commission in such form; other than a registration statement, if any, increasing the size of the offering (a "Rule 462(b) Registration Statement"), filed pursuant to Rule 462(b)