#1#2Legal Disclaimer Forward-Looking Statements This presentation includes "forward-looking statements" within the meaning of the federal securities laws, which involve risks and uncertainties. Forward-looking statements include all statements that do not relate solely to historical or current facts, and you can identify forward-looking statements because they contain words such as "believes," "expects," "may," "will," "should," "seeks," "intends," "trends," "plans," "estimates," "projects" or "anticipates" or similar expressions that concern our strategy, plans, expectations or intentions. All statements made relating to our estimated and projected earnings, margins, costs, expenditures, cash flows, growth rates and financial results are forward-looking statements. These forward-looking statements are subject to risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from future results, performance or achievements expressed or implied by such forward-looking statements. We derive many of our forward-looking statements from our operating budgets and forecasts, which are based upon many detailed assumptions. While we believe that our assumptions are reasonable, it is very difficult to predict the effect of known factors, and, of course, it is impossible to anticipate all factors that could affect our actual results. In light of the significant uncertainties inherent in the forward-looking statements included herein, the inclusion of such information should not be regarded as a representation by us or any other person that the results or conditions described in such statements or our objectives and plans will be realized. Important factors could affect our results and could cause results to differ materially from those expressed in our forward- looking statements, including but not limited to the factors discussed in the section entitled "Risk Factors" in Summit Inc.'s Annual Report on Form 10-K for the fiscal year ended December 30, 2017, as filed with the Securities and Exchange Commission and the following: our dependence on the construction industry and the strength of the local economies in which we operate; the cyclical nature of our business; risks related to weather and seasonality; risks associated with our capital-intensive business; competition within our local markets; our ability to execute on our acquisition strategy, successfully integrate acquisitions with our existing operations and retain key employees of acquired businesses; our dependence on securing and permitting aggregate reserves in strategically located areas; declines in public infrastructure construction and delays or reductions in governmental funding, including the funding by transportation authorities and other state agencies; environmental, health, safety and climate change laws or governmental requirements or policies concerning zoning and land use; conditions in the credit markets; our ability to accurately estimate the overall risks, requirements or costs when we bid on or negotiate contracts that are ultimately awarded to us; material costs and losses as a result of claims that our products do not meet regulatory requirements or contractual specifications; cancellation of a significant number of contracts or our disqualification from bidding for new contracts; special hazards related to our operations that may cause personal injury or property damage not covered by insurance; our substantial current level of indebtedness; our dependence on senior management and other key personnel; and interruptions in our information technology systems and infrastructure. All subsequent written and oral forward-looking statements attributable to us, or persons acting on our behalf, are expressly qualified in their entirety by these cautionary statements. Any forward-looking statement that we make herein speaks only as of the date of this presentation. We undertake no obligation to publicly update or revise any forward-looking statement as a result of new information, future events or otherwise, except as required by law. Non-GAAP Financial Measures Included in this presentation are certain non-GAAP financial measures, such as Adjusted EBITDA, Further Adjusted EBITDA, Adjusted Net Income (Loss), Adjusted Earnings Per Share, Adjusted Cash Gross Profit, Adjusted Cash Gross Profit Margin, Net Debt, Net Leverage and Free Cash Flow designed to complement the financial information presented in accordance with U.S. GAAP because management believes such measures are useful to investors. These non-GAAP financial measures should be considered only as supplemental to, and not superior to, financial measures provided in accordance with GAAP. Please refer to the appendix of this presentation for a reconciliation of the historical non-GAAP financial measures included in this presentation to the most directly comparable financial measures prepared in accordance with GAAP. Reconciliations of the non-GAAP measures used in this presentation are included or described in the tables attached to the appendix. Because GAAP financial measures on a forward-looking basis are not accessible, and reconciling information is not available without unreasonable effort, we have not provided reconciliations for forward-looking non-GAAP measures. 1 SUMMIT Materials#3#4#5Strong Momentum In Our Residential Markets Single Family Housing Starts vs. All-Time Cyclical Peak Single Family Housing Starts In Our Highest Growth Residential Markets All-Time Annual Peak vs. Full-Year 2017 (1) 70,000 60,000 50,000 40,000 30,000 20,000 10,000 (1) 0 33% From Peak Houston 20% From Peak Dallas/Ft. Worth ■2017 Single Family Starts (Projected) Source: JBREC, CoreLogic, Company Estimates as of February 2018 4 70% From Peak Las Vegas ■ Variance To All-Time Peak 25% From Peak Salt Lake City SUMMIT Materials#6#7Key States Stepping Up To The Plate Seeing Increased State/Local Funding In Our Footprint On Average, Federal Funding Supports 56% of Public Spending In Our Top 10 States (1) ...Yet, State/Local Funding Remains Critical To Driving Growth In Public Spending ■ ■ ■ ■ Less Reliant (1) (2) 34% Texas 42% Kentucky 43% Utah % STATE DOT BUDGET DERIVED FROM FEDERAL FUNDING POSITIVE PUBLIC OUTLOOK 49% Texas - 21% of Revenue (Prop 7 + $1.3 billion of new measures approved on Nov. 7, 2017) Missouri - 9% of Revenue (House Resolution 47 - Study to increase funding by $435 mm/yr) Colorado -6% of Revenue (Senate Bill 267 - $1.8 billion bond for road work in rural settings) lowa - 4% of Revenue (2015 gas tax increase resulted in an incremental $515 mm in funding) Minnesota - 3% of Revenue (Stable growth market w/ multi-year funding) Kansas 56% lowa 2018 Public Transportation Infrastructure Funding Outlook By SUM's Top 10 States (2) Top 10 States Represent More Than 80% of Gross Revenue H 57% Oklahoma Minnesota Missouri Utah - 13% of Revenue Virginia - 6% of Revenue Kentucky - 6% of Revenue H Oklahoma - 3% of Revenue 65% ARTBA 2018 Transportation Construction Market Forecast; Top 10 states as measured by gross revenue in FY17 Market point of view supported by state DOT STIP forecasts, Annual State Budgets and Company Estimates 71% 6 71% More Reliant Virginia STABLE PUBLIC OUTLOOK (-) NEGATIVE PUBLIC OUTLOOK 74% Colorado Kansas - 12% of Revenue - May upgrade to positive outlook pending increased state funding SUMMIT Materials#8#9#10#11#12Full-Year 2017 Price & Volume Analysis Y/Y Growth In Organic Materials Volumes Average Selling Price, Excluding Acquisitions (y/y % change) Aggregates -5.5% 4.8% -0.1% Sales Volume, Excluding Acquisitions (y/y % change) Aggregates 3.4% Cement Cement Ready-Mix Concrete 5.8% -3.4% -2.3% 3.3% Asphalt -13.0% 10.9% 2016 11 Average Selling Price, Including Acquisitions (y/y % change) 11.8% Aggregates 7.2% 15.6% 2017 Sales Volume, Including Acquisitions (y/y % change) Aggregates 1.2% Cement 37.0% 8.1% Cement 7.5% 12.2% Ready-Mix Concrete 22.4% 3.5% Asphalt 20.7% SUMMIT Materials#13#14#15#16#17#18#19#20#21#22#23#24#25#26#27#28#29#30#31#32#33#34#35#36#37