UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): September 20, 2017

Beacon Roofing Supply, Inc.

(Exact name of registrant as specified in its charter)

505 Huntmar Park Drive, Suite 300

Herndon, VA 20170

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code: (571) 323-3939

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company   ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☐

Item 8.01. Other Events.

On September 20, 2017, Beacon Roofing Supply, Inc. (the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with Citigroup Global Markets Inc. and Wells Fargo Securities, LLC, as representatives of the several underwriters named therein (collectively, the “Underwriters”), in connection with the public offering and sale by the Company (the “Offering”) of 6,325,000 shares (the “Shares”) of the Company’s common stock at a price to the public of $47.50 per share (the “Offering Price”). Pursuant to the Underwriting Agreement, the Company has granted the Underwriters a 30-day option to purchase up to an additional 948,750 shares of the Company’s common stock at the Offering Price.

The Company received notice of exercise of the Underwriter’s option to purchase the full 948,750 additional shares of the Company’s common stock on September 21, 2017 and the sale of the 948,750 additional shares of the Company’s common stock closed simultaneously with the Offering on September 25, 2017. Net proceeds received by the Company from its sale of 7,273,750 shares of the Company’s common stock were approximately $329.8 million, after deducting underwriting discounts and commissions and estimated offering expenses payable by the Company.

The Underwriting Agreement contains representations and warranties and covenants that are customary for transactions of this type. In addition, the Company has agreed to indemnify the Underwriters against certain liabilities on customary terms. The foregoing description of the Underwriting Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the Underwriting Agreement, a copy of which is filed herewith as Exhibit 1.1 and is incorporated herein by reference. In connection with the issuance of the Shares, Sidley Austin LLP provided the Company with the legal opinion attached to this Current Report on Form 8-K as Exhibit 5.1, and which is incorporated by reference herein.

The Underwriters and their affiliates have provided in the past to the Company and its affiliates and may provide from time to time in the future certain commercial banking, financial advisory, investment banking and other services for the Company and such affiliates in the ordinary course of their business, for which they have received and may continue to receive customary fees and commissions. In addition, from time to time, the Underwriters and their affiliates may effect transactions for their own account or the account of customers, and hold on behalf of themselves or their customers, long or short positions in the Company’s equity securities, debt securities or loans, and may do so in the future.

The offer and sale of the Shares was made pursuant to the Company’s effective shelf registration statement on Form S-3 (File No. 333- 220506) (the “Registration Statement”) filed with the U.S. Securities and Exchange Commission (the “SEC”) on September 18, 2017, including the prospectus contained therein dated September 18, 2017 and a related prospectus supplement dated September 20, 2017 on file with the SEC.

Item 9.01. Financial Statements and Exhibits.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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