GMS : September 2022 Investor Overview

Investor Overview

September 2022

Safe Harbor and Basis of Presentation

Forward-LookingStatement Safe Harbor - This presentation includes "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. You can generally identify forward-looking statements by the Company's use of forward-looking terminology such as "anticipate," "believe," "confident," "continue," "could," "estimate," "expect," "intend," "may," "might," "plan," "potential," "predict," "seek," or "should," or the negative thereof or other variations thereon or comparable terminology. In particular, statements about the markets in which GMS operates and or our products, including potential growth in those markets and products, the economy generally, actions taken to optimize our operations and align

our business consistent with demand, our ability to continue successfully navigating the evolving operating environment and executing our business, strategic initiatives and priorities and growth potential, future M&A and greenfields, product availability, inflation, capital structure, pricing, net sales, organic sales, gross margins, incremental EBITDA, Adjusted EBITDA, Adjusted EBITDA margin, interest expense, tax rates, capital expenditures, and free cash flow, cash flow generation and working capital management, future financial performance and liquidity, the ability of the Company to grow stronger, and the ability to deliver growth, value creation and long-term success contained in this presentation may be considered forward- looking statements. Statements about our expectations, beliefs, plans, strategies, objectives, prospects, assumptions or future events or performance may be considered forward-looking statements. The Company has based forward-looking statements on its current expectations, assumptions, estimates and projections. While the Company believes these expectations, assumptions, estimates and projections are reasonable, such forward-looking statements are only predictions and involve known and unknown risks and uncertainties, many of which are beyond its control, including current public health issues that may affect the Company's business. Forward-looking statements involve risks and uncertainties, including, but not limited to,

those described in the "Risk Factors" section in the Company's most recent Annual Report on Form 10-K, and in its other periodic reports filed with the SEC. In addition, the statements in

this release are made as of September 6, 2022. The Company undertakes no obligation to update any of the forward-looking statements made herein, whether as a result of new information, future events, changes in expectation or otherwise. These forward-looking statements should not be relied upon as representing the Company's views as of any date subsequent to September 6, 2022.

Use of Non-GAAPand Adjusted Financial Information - To supplement GAAP financial information, we use adjusted measures of operating results which are non-GAAP measures. This non-GAAP adjusted financial information is provided as additional information for investors. These adjusted results exclude certain costs, expenses, gains and losses, and we believe their exclusion can enhance an overall understanding of our past financial performance and also our prospects for the future. These adjustments to our GAAP results are made with the intent of providing both management and investors a more complete understanding of our operating performance by excluding non-recurring, infrequent or other non-cash charges that are not believed to be material to the ongoing performance of our business. The presentation of this additional information is not meant to be considered in isolation or as a substitute for GAAP measures of net income, diluted earnings per share or net cash provided by (used in) operating activities prepared in accordance with generally accepted accounting principles in the United States. Please see the Appendix to this presentation for a further discussion on these non-GAAP measures and a reconciliation of these non-GAAP measures to the most directly comparable GAAP measures.

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GMS at a Glance

51yrs

Founded in

1971

~300

Distribution yard

locations across the

U.S.

& Canada

$4.6B

Fiscal 2022

Net Sales

100+

Tool Sales, Rentals & Service Centers

$566.9M

Fiscal 2022

Adj. EBITDA*

~6,700

GMS Team Members

50+

Leading Brands

GMS

NYSE Ticker

Symbol

*For a reconciliation of Adjusted EBITDA to the most directly comparable GAAP metrics, see Appendix.

Information as of June 2022 unless otherwise noted

Diversified and Balanced End Market Exposure

Diversified exposure across commercial and residential new and repair and remodel construction markets continues to be an advantage

Net Sales Breakdown Fiscal 2022*

~45%	~55%
Residential	Commercial
•	Single-Family New	•	New Construction
•	Multi-Family New	•	Repair & Remodel
•	Repair & Remodel

*Adjusted for the estimated impact of steel price inflation experienced during fiscal 2022

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Providing Value to Contractors and Builders

A Leading North American specialty distributor of construction products

GMS provides the products and value-added services to contractors who install wallboard, ceilings, steel framing and other complementary building products

Net Sales Breakdown (Fiscal 2022)

29%

COMPLEMENTARY

PRODUCTS

• Expertise across local markets, leveraging scaled North
  American footprint​
• One-stop-shopfor contractors with a broad product offering​
• Critical link between suppliers and a highly fragmented customer base​

22%*

STEEL FRAMING

37%

WALLBOARD

12%

CEILINGS

*Steel framing experienced significant product price inflation during fiscal 2022.	5
As a comparison, steel framing contributed 14% of fiscal 2021's net sales.