RPM INTERNATIONAL INC/DE/

This summary highlights information contained elsewhere in this Proxy Statement and in the Company’s Annual Report on Form 10-K. For more complete information about these topics, please review the Company’s complete Proxy Statement and Annual Report on Form 10-K.

Voting Recommendations

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RPM International Inc.

RPM International Inc. owns subsidiaries that are world leaders in specialty coatings, sealants, building materials and related services. The Company operates across three reportable segments: consumer, construction products and performance coatings. RPM has a diverse portfolio of market-leading brands, including Rust-Oleum, DAP, Zinsser, Varathane, The Pink Stuff, Stonhard, Carboline, Finish Works, Tremco, Euclid Chemical, Dryvit and Nudura. From homes and workplaces to infrastructure and precious landmarks, RPM’s brands are trusted by consumers and professionals alike to help build a better world. The Company employs approximately 17,500 individuals worldwide.

The Company’s consolidated net sales, net income, diluted earnings per share and cash provided by operating activities for the fiscal year ended May 31, 2026, were as follows:

Increased Cash Dividend Every Year for 52 Consecutive Years

On October 2, 2025, the Board of Directors increased the quarterly dividend on shares of the Company’s Common Stock to $0.54 per share, an increase of 5.9% from the prior year and the highest ever paid by the Company. With a 52-year track record of a continuously increasing cash dividend, the Company is in an elite category of less thanone-half of one percent of all publicly traded U.S. companies to have increased the dividend for this period of time or longer, according to Stockanalysis.com. Only 39 other publicly traded U.S. companies, besides the Company, have consecutively paid an increasing annual dividend for a longer period of time. During this timeframe, the Company has returned approximately $3.9 billion in cash dividends to its stockholders.

Stock Repurchase Program

During the fiscal year ended May 31, 2026, the Company repurchased 699,931 shares of Common Stock under this program at a cost of approximately $77.5 million, or an average cost of $110.72 per share. During the fiscal year ended May 31, 2025, the Company repurchased 581,759 shares of Common Stock under this program at a cost of approximately $70.0 million, or an average cost of $120.32 per share. During the fiscal year ended May 31, 2024, the Company repurchased 526,113 shares of Common Stock under this program at a cost of approximately $55.0 million, or an average cost of $104.50 per share. The maximum dollar amount that may yet be repurchased under the repurchase program was approximately $114.8 million as of May 31, 2026. In July 2026, the Board of Directors increased the maximum dollar amount that may yet be repurchased under the repurchase program by an additional $700.0 million.

Additional information regarding the Company’s stock repurchase program can be found in Note I of the Notes to Consolidated Financial Statements of the Company’s Annual Report on Form 10-K.

Corporate Governance

The Company is committed to meeting high standards of ethical behavior, corporate governance and business conduct. This commitment has led the Company to implement the following practices:

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See also “Information Regarding Meetings and Committees of the Board of Directors” at page 24 for further information on the Company’s governance practices. Additional information about our majority voting policy appears under the caption “Voting Rights” on page 10.

RPM INTERNATIONAL INC. STATEMENT OF GOVERNANCE POLICY

Our fundamental objective is to build long-term stockholder value by profitably growing our businesses and consistently delivering strong financial performance. We think that our ability to generate value for our stockholders is inextricably linked to our ability to provide value to our principal stakeholders, including our customers and associates. • We continue to earn the ongoing commitment and trust of our stockholders by delivering the solid returns expected by them from an investment in RPM. • We strive to offer our customers innovative, high-quality products and services at competitive prices. • We endeavor to attract and retain high-quality associates at every level of our organization, provide them with the tools they need to do their jobs, and compensate them in such a way as to closely align their interests with our long-term success. • We conduct our business in conformity with The Values & Expectations of 168, which encompass complying with all applicable legal requirements, and with the ethical standards we prescribe, working to be exemplary corporate citizens. We do not focus narrowly on efforts to maximize the short-term price of our stock and view such an approach as fundamentally misguided. Instead, we must emphasize consistent value creation in our businesses in an effort to maximize the long-term value of our stockholders’ investment. In short, we manage our businesses to create wealth for our stockholders. Creating value for our stakeholders is how we have achieved, and will continue to achieve, that objective.

Experience, Qualifications, Attributes and Skills of Director Nominees

The Board of Directors believes that all the Company’s Director nominees have specific life, employment and leadership experiences and skills that qualify them for service on the Board of Directors. Such qualities are included in their individual biographies and also summarized in the following table:

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The Board of Directors seeks to comprise itself of members which, collectively, possess a range of relevant skills, characteristics, experience and expertise. In selecting potential Director candidates for nomination, the Governance and Nominating Committee and the Board of Directors consider the composition of the Board of Directors as a whole when selecting the most qualified candidate to serve on the Board of Directors. This evaluation is performed in light of the Governance and Nominating Committee’s views as to the needs of the Board of Directors and the Company as well as what skill set, qualifications, experience and other characteristics would most complement those of the then-current Directors.

Enterprise-Wide Risk Oversight

The Board of Directors, assisted by its committees, oversees management’s enterprise-wide risk management activities. Risk management activities include assessing and taking actions necessary to manage risk incurred in connection with the long-term strategic direction and operation of the Company’s business. See “Information Regarding Meetings and Committees of the Board of Directors – Role in Risk Oversight” for further information.

Executive Compensation

The Company’s executive compensation program utilizes a mix of base salary, annual cash incentives, equity awards and standard benefits to attract and retain highly qualified executives and maintain a strong relationship between executive pay and Company performance. Ninety-two percent (92%) of the votes cast on the Say-on-Pay proposal last year were voted in support of the compensation of our named executive officers.

Overall Compensation Program Principles

Pay for performance – The Company’s general compensation philosophy is performance-based in that the Company’s executive officers should be well compensated for achieving strong operating and financial results. The Company engages in a rigorous process intended to provide its executive officers a fair level of compensation that reflects the Company’s positive operating financial results, the relative skills and experience of the individuals involved, Compensation Peer Group compensation levels and other similar benchmarks.

Compensation weighted towardat-risk pay – The mix of compensation of the Company’s named executive officers is weighted towardat-risk pay (consisting of cash and equity compensation). Maintaining this pay mix results in apay-for-performance orientation, which aligns to the Company’s compensation philosophy of paying total direct compensation that is competitive with peer group levels based on relative company performance. For fiscal 2026, 55% of the totals shown in the Summary Compensation Table for our named executive officers was variable and tied to our performance.

Compensation Benchmark Study – In 2026, the Compensation Committee retained the professional consulting firm of Willis Towers Watson to conduct an executive compensation benchmark study. Based on its analysis and findings, Willis Towers Watson concluded that our Chief Executive Officer’s target total direct compensation was above the 50 th percentile with a significant portion of compensation linked to performance-based equity. Overall, our named executive officers’ salaries and total target cash compensation are generally below the market median, and their long-term incentives and total direct compensation are generally at or above the market median.

Summary of Compensation Paid to Frank C. Sullivan, the Company’s Chief Executive Officer, in Fiscal 2026

Stockholder Actions

Proposal One – Election of Directors (see pages 11 – 23)

The Board of Directors has nominated twelve candidates for election to serve on the Board. The Board recommends that stockholders vote FOR the election of each nominee.

Proposal Two – Advisory Vote to Approve the Company’s Executive Compensation (see pages 31 – 32)

The Board of Directors is seeking an advisory vote to approve the Company’s executive compensation. Before considering this proposal, please read the Compensation Discussion and Analysis in this Proxy Statement, which explains the Compensation

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Committee’s compensation decisions and how the Company’s executive compensation program aligns the interests of the executive officers with those of the Company’s stockholders. Although the vote is advisory and is not binding on the Board of Directors, the Compensation Committee will take into account the outcome of the vote when considering future executive compensation decisions. The Board recommends that stockholders vote FOR the approval of the Company’s executive compensation.

Proposal Three – Ratification of Appointment of Independent Registered Public Accounting Firm (see page 71)

The Audit Committee has appointed Deloitte & Touche LLP as the Company’s independent registered public accounting firm for the fiscal year ending May 31, 2027. The Board of Directors is seeking stockholder ratification of this appointment. The Board recommends that stockholders vote FOR ratification of the selection of Deloitte & Touche LLP.

VIRTUAL ANNUAL MEETING INFORMATION The Company will be hosting a virtual Annual Meeting. Stockholders will be able to participate in the Annual Meeting online, in virtual meeting format, via live webcast. Provided below is the summary of the information that you will need to participate in the Annual Meeting: • Stockholders can participate in the Annual Meeting online, in virtual meeting format, via live webcast over the Internet at www.virtualshareholdermeeting.com/RPM2026. • You will need your unique control number, which is provided on your notice of internet availability or proxy card, to vote and submit questions during the Annual Meeting webcast. • The webcast of the Annual Meeting will begin at 1:30 p.m., Eastern Daylight Time. • Instructions as to how to participate via the Internet, including how to verify stock ownership, are available at www.virtualshareholdermeeting.com/RPM2026. • If you have questions regarding how to vote your shares of Common Stock, you may call Innisfree M&A Incorporated, at (877) 687-1865 (Toll Free). • Replay of the Annual Meeting webcast will be available until October 7, 2027.