Exhibit 99.1

SUMMIT MATERIALS, LLC AND SUBSIDIARIES

Consolidated Balance Sheets

(In thousands)

See notes to unaudited consolidated financial statements.

SUMMIT MATERIALS, LLC AND SUBSIDIARIES

Unaudited Consolidated Statements of Operations

(In thousands)

See notes to unaudited consolidated financial statements.

SUMMIT MATERIALS, LLC AND SUBSIDIARIES

Unaudited Consolidated Statements of Comprehensive Operations

(In thousands)

See notes to unaudited consolidated financial statements.

SUMMIT MATERIALS, LLC AND SUBSIDIARIES

Unaudited Consolidated Statements of Cash Flows

(In thousands)

See notes to unaudited consolidated financial statements.

SUMMIT MATERIALS, LLC AND SUBSIDIARIES

Unaudited Consolidated Statements of Changes in Member’s Interest and Redeemable Noncontrolling Interest

(In thousands)

See notes to unaudited consolidated financial statements.

SUMMIT MATERIALS, LLC

NOTES TO UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS

(Tables in thousands)

1.SUMMARY OF ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES

Summit Materials, LLC (“Summit LLC” and, together with its subsidiaries, the “Company”) is a vertically integrated, construction materials company. The Company is engaged in the production and sale of aggregates, cement, ready-mix concrete, asphalt paving mix and concrete products and owns and operates quarries, sand and gravel pits, two cement plants, cement distribution terminals, ready-mix concrete plants, asphalt plants and landfill sites. It is also engaged in paving and related services. The Company’s three operating and reporting segments are the West, East and Cement segments.

Substantially all of the Company’s products and services are produced, consumed and performed outdoors, primarily in the spring, summer and fall. Seasonal changes and other weather-related conditions can affect the production and sales volumes of its products and delivery of services. Therefore, the financial results for any interim period are typically not indicative of the results expected for the full year. Furthermore, the Company’s sales and earnings are sensitive to national, regional and local economic conditions and to cyclical changes in construction spending, among other factors.

Summit LLC is a wholly owned indirect subsidiary of Summit Materials Holdings L.P. (“Summit Holdings”), whose primary owner is Summit Materials, Inc. (“Summit Inc.”). Summit Inc. was formed as a Delaware corporation on September 23, 2014. Its sole material asset is a controlling equity interest in Summit Holdings. Pursuant to a reorganization into a holding company structure (the “Reorganization”) in connection with Summit Inc.’s March 2015 initial public offering, Summit Inc. became a holding corporation operating and controlling all of the business and affairs of Summit Holdings and its subsidiaries, including Summit LLC.

Summit Inc. Equity Offering—On January 10, 2017, Summit Inc. raised $237.6 million, net of underwriting discounts, through the issuance of 10,000,000 shares of Class A common stock at a public offering price of $24.05 per share. Summit Inc. used these proceeds to purchase an equal number of limited partnership interests in Summit Holdings (“LP Units”) and caused Summit Holdings to use a portion of the proceeds from the offering to acquire two materials-based companies for a combined purchase price of approximately $110 million in cash, with remaining net proceeds to be used for general corporate purposes, which may include, but is not limited to, funding acquisitions, repaying indebtedness, capital expenditures and funding working capital.

Basis of Presentation—These unaudited consolidated financial statements were prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and footnote disclosures typically included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. These unaudited consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto as of and for the year ended December 31, 2016. The Company continues to follow the accounting policies set forth in those consolidated financial statements.

Management believes that these consolidated interim financial statements include all adjustments, normal and recurring in nature, that are necessary to present fairly the financial position of the Company as of April 1, 2017, and the results of operations and cash flows for the three months ended April 1, 2017 and April 2, 2016

Principles of Consolidation–The consolidated financial statements include the accounts of Summit LLC and its majority owned subsidiaries. All intercompany balances and transactions have been eliminated. The Company attributes consolidated member’s interest and net income separately to the controlling and noncontrolling interests. Noncontrolling interests in consolidated subsidiaries represent a 20% ownership in Ohio Valley Asphalt, LLC. The Company accounts for investments in entities for which it has an ownership of 20% to 50% using the equity method of accounting.

Use of Estimates—Preparation of these consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities and reported amounts of revenue and expenses. Such estimates include the valuation of accounts receivable, inventories, valuation of deferred tax assets, goodwill, intangibles and other long-lived assets, pension and other postretirement obligations and asset retirement obligations. Estimates also include revenue earned on contracts and costs to complete contracts. Most of the Company’s paving and related services are performed under fixed unit-price contracts with state and local governmental entities. Management regularly evaluates its estimates and assumptions based on historical experience and other factors, including the current economic environment. As future events and their effects cannot be determined with precision, actual results can differ significantly from estimates made. Changes in estimates, including those resulting from continuing changes in the economic environment, are reflected in the Company’s consolidated financial statements when the change in estimate occurs.

Business and Credit Concentrations—The Company’s operations are conducted primarily across 21 U.S. states and in British Columbia, Canada, with the most significant revenue generated in Texas, Kansas, Utah and Missouri. The Company’s accounts receivable consist primarily of amounts due from customers within these areas. Therefore, collection of these accounts is dependent on the economic conditions in the aforementioned states, as well as specific situations affecting individual customers. Credit granted within the Company’s trade areas has been granted to many customers, and management does not believe that a significant concentration of credit exists with respect to any individual customer or group of customers. No single customer accounted for more than 10% of the Company’s total revenue in the three months ended April 1, 2017 and April 2, 2016.

Fair Value Measurements—Certain acquisitions made by the Company require the payment of contingent amounts of purchase consideration. These payments are contingent on specified operating results being achieved in periods subsequent to the acquisition and will only be made if earn-out thresholds are achieved. Contingent consideration obligations are measured at fair value each reporting period. Any adjustments to fair value are recognized in earnings in the period identified.

The Company has entered into interest rate derivatives on $200.0 million of its term loan borrowings to add stability to interest expense and to manage its exposure to interest rate movements. The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive loss and will be subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The fair value of contingent consideration and derivatives as of April 1, 2017 and December 31, 2016 was:

The fair value of contingent consideration was based on unobservable, or Level 3, inputs, including projected probability-weighted cash payments and an 11.0% discount rate, which reflects a market discount rate. Changes in fair value may occur as a result of a change in actual or projected cash payments, the probability weightings applied by the Company to projected payments or a change in the discount rate. Significant increases or decreases in any of these inputs in isolation could result in a lower, or higher, fair value measurement. The fair value of the cash flow hedges are based on observable, or Level 2, inputs such as interest rates, bond yields and prices in inactive markets. There were no material valuation adjustments to contingent consideration or derivatives in the three months ended April 1, 2017 and April 2, 2016.

Financial Instruments—The Company’s financial instruments include debt and certain acquisition-related liabilities (deferred consideration and noncompete obligations). The carrying value and fair value of these financial instruments as of April 1, 2017 and December 31, 2016 was:

The fair value of debt was determined based on observable, or Level 2 inputs, such as interest rates, bond yields and quoted prices in inactive markets. The fair values of the deferred consideration and noncompete obligations were determined based on unobservable, or Level 3, inputs, including the cash payment terms in the purchase agreements and a discount rate reflecting the Company’s credit risk. The discount rate used is generally consistent with that used when the obligations were initially recorded.

Securities with a maturity of three months or less are considered cash equivalents and the fair value of these assets approximates their carrying value.

New Accounting Standards — In March 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, which requires that the service cost component be reported in the same line item as employer compensation costs and that the other components of periodic pension costs be reported outside of operating income. The ASU also restricts capitalization of costs to the service cost component. The ASU is effective for public companies for annual periods beginning after December 15, 2017. The Company early adopted this ASU as of the beginning of fiscal year 2017, on a retrospective basis; accordingly, the Company reclassified $98,000 from product cost of revenue to other (income) expense in the three months ended April 2, 2016 to conform to the current year presentation.

In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment, which eliminates the two step goodwill impairment test and replaces it with a single step test.  The single step test compares the carrying amount of a reporting unit to its fair value; if the carrying amount is greater than the fair value the difference is the amount of the goodwill impairment.  Step zero is left unchanged. Therefore, entities that wish to do a qualitative assessment are still permitted to do so. The ASU is effective for SEC filers for fiscal years beginning after December 15, 2020. However, the Company early adopted this ASU as of the beginning of fiscal year 2017. The adoption of this ASU did not have a material impact on the consolidated financial statements.

In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, which requires that the income tax effect of share-based awards be recognized in the income statement and allows entities to elect an accounting method to recognize forfeitures as they occur or to estimate forfeitures. The Company early adopted this ASU as of the beginning of fiscal year 2016 and made an election to recognize forfeitures as they occur. The ASU adoption was applied using a modified retrospective method by means of a $1.7 million cumulative-effect adjustment to accumulated earnings (deficit) as of the beginning of the fiscal year.

2.ACQUISITIONS

The Company has completed numerous acquisitions since its formation, which have been financed through a combination of debt and equity funding. The operations of each acquisition have been included in the Company’s consolidated results of operations since the respective closing dates of the acquisitions. The Company measures all assets acquired and liabilities assumed at their acquisition-date fair value. The following acquisitions completed in the three months ended April 1, 2017 and in fiscal 2016 were not material individually, or when combined:

West segment

East segment

Cement segment

The purchase price allocation, primarily the valuation of property, plant and equipment for the 2017 acquisitions, as well as certain of the 2016 acquisitions has not yet been finalized due to the timing of the acquisitions. The following table summarizes aggregated information regarding the fair values of the assets acquired and liabilities assumed as of the respective acquisition dates:

Changes in the carrying amount of goodwill, by reportable segment, from December 31, 2016 to April 1, 2017 are summarized as follows:

The Company’s intangible assets are primarily composed of goodwill, lease agreements and reserve rights. The assets related to lease agreements reflect the submarket royalty rates paid under agreements, primarily, for extracting aggregates. The values were determined as of the respective acquisition dates by a comparison of market-royalty rates. The reserve rights relate to aggregate reserves to which the Company has the rights of

ownership, but does not own the reserves. The intangible assets are amortized on a straight-line basis over the lives of the leases. The following table shows intangible assets by type and in total:

Amortization expense totaled $0.3 million and $0.4 million for the three months ended April 1, 2017 and April 2, 2016, respectively. The estimated amortization expense for the intangible assets for each of the five years subsequent to April 1, 2017 is as follows:

3.ACCOUNTS RECEIVABLE, NET

Accounts receivable, net consisted of the following as of April 1, 2017 and December 31, 2016:

Retention receivables are amounts earned by the Company but held by customers until paving and related service contracts and projects are near completion or fully completed. Amounts are generally billed and collected within one year.

4.INVENTORIES

Inventories consisted of the following as of April 1, 2017 and December 31, 2016:

5.ACCRUED EXPENSES

Accrued expenses consisted of the following as of April 1, 2017 and December 31, 2016:

6.DEBT

Debt consisted of the following as of April 1, 2017 and December 31, 2016:

The contractual payments of long-term debt, including current maturities, for the five years subsequent to April 1, 2017, are as follows:

Senior Notes— On March 8, 2016, Summit LLC and Summit Materials Finance Corp., an indirect wholly-owned subsidiary of Summit LLC ("Finance Corp." and with Summit LLC, the “Issuers”) issued $250.0 million of 8.500% senior notes due April 15, 2022 (the “2022 Notes”). The 2022 Notes were issued at 100.0% of their par value with proceeds of $246.3 million, net of related fees and expenses. The proceeds from the sale of the 2022 Notes were used to fund the acquisition of Boxley, replenish cash used for the acquisition of AMC and pay expenses incurred in connection with these acquisitions. The 2022 Notes were issued under an indenture dated March 8, 2016 (as amended and supplemented, the “2016 Indenture”). The 2016 Indenture contains covenants limiting, among other things, Summit LLC and its restricted subsidiaries’ ability to incur additional indebtedness or issue certain preferred shares, pay dividends, redeem stock or make other distributions, make certain investments, sell or transfer certain assets, create liens, consolidate, merge, sell or otherwise dispose of all or substantially all of its assets, enter into certain transactions with affiliates, and designate subsidiaries as unrestricted subsidiaries. The 2016 Indenture also contains customary events of default. Interest on the 2022 Notes is payable semi-annually in arrears on April 15 and October 15 of each year.

In 2015, the Issuers issued $650.0 million of 6.125% senior notes due July 2023 (the “2023 Notes” and collectively with the 2022 Notes, the “Senior Notes”). Of the aggregate $650.0 million of 2023 Notes, $350.0 million were issued at par and $300.0 million were issued at 99.375% of par. The 2023 Notes were issued under an indenture dated July 8, 2015, the terms of which are generally consistent with the 2016 Indenture. Interest on the 2023 Notes is payable semi-annually in arrears on January 15 and July 15 of each year.

As of April 1, 2017 and December 31, 2016, the Company was in compliance with all financial covenants under the applicable indentures.

Senior Secured Credit Facilities— Summit LLC has credit facilities that provide for term loans in an aggregate amount of $650.0 million and revolving credit commitments in an aggregate amount of $235.0 million (the “Senior Secured Credit Facilities”). Under the Senior Secured Credit Facilities, required principal repayments of 0.25% of the original aggregate amount of term debt are due on the last business day of each March, June, September and December. The unpaid principal balance is due in full on the maturity date, which is July 17, 2022.

On January 19, 2017, Summit LLC entered into Amendment No. 1 (“Amendment No. 1”) to the credit agreement governing the Senior Secured Credit Facilities (the “Credit Agreement”), which, among other things, reduced the applicable margin in respect of the $640.3 million outstanding principal amount of term loans thereunder and included a 1.00% prepayment premium in connection with certain further repricing events that occur on or prior to the six-month anniversary of the effective date of Amendment No. 1. All other material terms and provisions remain substantially identical to the terms and provisions in place immediately prior to the effectiveness of Amendment No. 1.

The revolving credit facility bears interest per annum equal to, at Summit LLC’s option, either (i) a base rate determined by reference to the highest of (a) the federal funds rate plus 0.50%, (b) the prime rate of Bank of America, N.A. and (c) LIBOR plus 1.00%, plus an applicable margin of 2.25% for base rate loans or (ii) a LIBOR rate determined by reference to Reuters prior to the interest period relevant to such borrowing adjusted for certain additional costs plus an applicable margin of 3.25% for LIBOR rate loans.

There were no outstanding borrowings under the revolving credit facility as of April 1, 2017 and December 31, 2016, leaving remaining borrowing capacity of $215.4 million as of April 1, 2017, which is net of $19.6 million of outstanding letters of credit. The outstanding letters of credit are renewed annually and support required bonding on construction projects and the Company’s insurance liabilities.

Summit LLC’s Consolidated First Lien Net Leverage Ratio, as such term is defined in the Credit Agreement, should be no greater than 4.75:1.0 as of each quarter-end. As of April 1, 2017 and December 31, 2016, Summit LLC was in compliance with all financial covenants.

Summit LLC’s wholly-owned domestic subsidiary companies, subject to certain exclusions and exceptions, are named as subsidiary guarantors of the Senior Notes and the Senior Secured Credit Facilities. In addition, Summit LLC has pledged substantially all of its assets as collateral, subject to certain exclusions and exceptions, for the Senior Secured Credit Facilities.

Interest expense related to debt totaled $21.6 million and $18.3 million in the three months ended April 1, 2017 and April 2, 2016, respectively.

The following table presents the activity for the deferred financing fees for the three months ended April 1, 2017 and April 2, 2016:

Other—On January 15, 2015, the Company’s wholly-owned subsidiary in British Columbia, Canada entered into an agreement with HSBC for a (i) $6.0 million Canadian dollar (“CAD”) revolving credit commitment to be used for operating activities that bears interest per annum equal to the bank’s prime rate plus 0.20%, (ii) $0.5 million CAD revolving credit commitment to be used for capital equipment that bears interest per annum at the bank’s prime rate plus 0.90% and (iii) $0.4 million CAD revolving credit commitment to provide guarantees on behalf of that subsidiary. There were no amounts outstanding under this agreement as of April 1, 2017 or December 31, 2016.

7.ACCUMULATED OTHER COMPREHENSIVE LOSS

The changes in each component of accumulated other comprehensive loss consisted of the following: