NOTE 18. LITIGATION AND RELATED MATTERS

ENVIRONMENTAL MATTERS

Environmental Compliance

Our manufacturing and research facilities are affected by various federal, state and local requirements relating to the discharge of materials and the protection of the environment. We make expenditures necessary for compliance with applicable environmental requirements at each of our operating facilities. While these expenditures are not typically material, the applicable regulatory requirements continually change and, as a result, we cannot predict with certainty the amount, nature or timing of future expenditures associated with environmental compliance.

Environmental Sites

Summary

We are actively involved in the investigation and remediation of existing or potential environmental contamination under the Comprehensive Environmental Response, Compensation and Liability Act (“CERCLA”) and state Superfund and similar environmental laws at two domestically owned locations allegedly resulting from past industrial activity.

In each location, we are one of multiple potentially responsible parties and have agreed to jointly fund the required investigation and remediation, while preserving our defenses to the liability. We may also have rights of contribution or reimbursement from other parties or coverage under applicable insurance policies. We have pursued coverage and recoveries under those applicable insurance policies with respect to certain of the sites, including the Macon, Georgia site and the Elizabeth City, North Carolina site, each of which is summarized below. Other than disclosed below, we are unable to predict the outcome of these matters or the timing of any future recoveries, whether through settlement or otherwise. We are also unable to predict the extent to which any recoveries might cover our final share of investigation and remediation costs for these sites. Our final share of investigation and remediation costs may exceed any such recoveries, and such amounts net of insurance recoveries may be material.

Between 2017 and 2021, we entered into settlement agreements totaling $53.0 million with certain legacy insurance carriers to resolve ongoing litigation and recover fees and costs previously incurred by us in connection with certain environmental sites. These settlements were recorded as reductions to cost of goods sold and SG&A expenses, reflecting the same income statement categories where environmental expenditures were historically recorded. From 2020 through the third quarter of 2024, cumulative insurance recoveries exceeded cumulative expenses to date related to the respective environmental sites and the excess was recorded within long-term liabilities on our Condensed Consolidated Balance Sheets. These excess recoveries were released to offset additional reserves for potential liabilities incurred on the respective environmental sites. We may enter into additional settlement agreements in the future, which may or may not be material, with other legacy insurers to obtain reimbursement or contribution for environmental site expenses.

Estimates of our future liability at the environmental sites are based on evaluations of currently available facts regarding each individual site. We consider factors such as our activities associated with the site, existing technology, presently enacted laws and regulations and prior company experience in remediating contaminated sites. Although current law imposes joint and several liability on all parties at Superfund sites, our contribution to the remediation of these sites is expected to be limited by the number of other companies potentially liable for site remediation. As a result, our estimated liability reflects only our expected share. In determining the probability of contribution, we consider the solvency of other parties, the site activities of other parties, whether liability is being disputed, the terms of any existing agreements and experience with similar matters, and the effect of our October 2006 Chapter 11 reorganization and separation with Armstrong Flooring, Inc. upon the validity of the claim, if any.

Specific Material Events

Macon, Georgia

The U.S. Environmental Protection Agency (the “EPA”) has listed two landfills located on a portion of our facility in Macon, Georgia, along with the former Macon Naval Ordnance Plant landfill adjacent to our property, portions of Rocky Creek, and certain tributaries leading to Rocky Creek (collectively, the “Macon Site”) as a Superfund site on the National Priorities List due to the presence of contaminants, most notably polychlorinated biphenyls (“PCBs”).

In September 2010, we entered into an Administrative Order on Consent for a Removal Action (the “Removal Action”) with the EPA to investigate PCB contamination in one of the landfills on our property, the Wastewater Treatment Plant Landfill (“Operable Unit 1”). After completing an investigation of Operable Unit 1 and submitting our final Engineering Evaluation/Cost Analysis, the EPA issued an Action Memorandum in July 2013 selecting our recommended remedy for the Removal Action. The Operable Unit 1 final

report was submitted to the EPA in October 2016, the EPA approved the final report in November 2016, and a Post-Removal Control Plan was submitted to the EPA in March 2017. AWI has been conducting operation and maintenance activities of the completed remedy since 2017 consistent with the approved Post-Removal Control Plan.

In September 2015, AWI and other Potentially Responsible Parties (“PRPs”) received a Special Notice Letter from the EPA under CERCLA inviting AWI and the PRPs to enter into the negotiation of a Remedial Investigation and Feasibility Study (“RI/FS”) with respect to the remainder of the Superfund site, which included the other landfill on our property, as well as areas on and adjacent to our property and Rocky Creek (“Operable Unit 2”). In the second half of 2022, the EPA and the PRPs agreed to separate all non-groundwater aspects of the site from the ongoing groundwater investigation.

Based on findings in a Remedial Investigation Report (“RIR”) which included relevant risk assessments previously conducted and that was approved by the EPA in July 2023, the PRPs developed and submitted to the EPA a draft Feasibility Study (“FS”) to identify and evaluate potential remedial alternatives for all non-groundwater elements of Operable Unit 2. Following review and comment by the EPA and the State of Georgia and revisions to the FS to address those comments, the EPA conditionally approved the FS in April 2024 and issued a Proposed Remedial Action Plan (“Proposed Plan”) for the non-groundwater elements at the site in May 2024, which included a total cost estimate for the non-groundwater elements at the site of approximately $8 million. In August 2024, the EPA signed the Record of Decision, selecting the remedy outlined in the Proposed Plan. In April 2026, the EPA issued a Special Notice Letter to the PRPs to conduct the Remedial Design/Remedial Action (“RD/RA”) for the Operable Unit 2 remedy. The portion of these remediation costs that AWI will bear for all non-groundwater elements of Operable Unit 2 will be formalized once the PRPs resolve the final allocation of costs, with that process expected to begin in August 2026.

In March 2025, AWI and the other PRPs proposed that the investigation of the groundwater elements of the areas constituting Operable Unit 2 (now designated as “Operable Unit 3”), be completed in conjunction with the groundwater investigation at the adjacent former Macon Naval Ordnance Plant landfill, however, the EPA rejected this request and required two separate remedial investigation reports.

It is probable that we will incur field investigation, engineering and oversight costs associated with designing and implementing the RD/RA remedy for all non-groundwater elements of Operable Unit 2 and for completing an RI/FS of Operable Unit 3. We may also ultimately incur costs in remediating contamination discovered during the RI/FS for Operable Unit 3, and we are unable to reasonably estimate our final share of the total costs associated with the investigation work or any resulting remediation therefrom, although such amounts may be material to any one quarter’s or year’s results of operations in the future. We do not expect the total future costs to have a material adverse effect on our liquidity or financial condition as the cash payments may be made over many years.

Elizabeth City, North Carolina

This site is a former cabinet manufacturing facility that from 1977 until 1996 was operated by Triangle Pacific Corporation, which became Armstrong Wood Products, Inc. (“AWP”), and is now known as AHF Products, LLC. The site was formerly owned by the U.S. Navy (“Navy”) and Westinghouse, which was purchased by Paramount, a Skydance Corporation (“Paramount”) (then known as CBS Corporation). We assumed ownership of the site when we acquired the stock of AWP in 1998. In connection with the separation of Armstrong Flooring, Inc. in 2016, we agreed to retain any legacy environmental liabilities associated with the AWP site.

Prior to our acquisition of the site, the North Carolina Department of Environment and Natural Resources listed the site as a hazardous waste site. In 1997, AWP entered into a cost sharing agreement with Westinghouse whereby the parties agreed to share equally the costs associated with site investigation. In 2007, we and Paramount entered into an agreement with the Navy whereby the Navy agreed to pay one third of defined past and future investigative costs up to a certain amount, which has now been exhausted. The EPA approved an RI/FS work plan for the site in August 2011. In July 2018, the EPA published an Interim Record Of Decision (“IROD”) selecting an interim cleanup approach. In June 2021, we entered into a negotiated Partial Consent Decree and Site Participation Agreement with the EPA, Paramount and the U.S. on behalf of the Navy for the remedial design and remedial action for the interim remedy. Because the U.S. does not conduct work as a PRP at Superfund sites, similar to the 2007 agreement, the U.S. agreed to pay its share of the estimated costs of performing the work and, as part of the Consent Decree Financial Assurance, the Company and Paramount also funded their estimated shares of the Interim Remedy. The Partial Consent Decree was entered by the U.S. District Court for the Eastern District of North Carolina in January 2022. A Remedial Design Work Plan was approved by the EPA in February 2023 and in December 2024, the EPA approved the Pre-Design Investigation Work Plan and related Quality Assurance Project Plan. In March 2026, the initial assessment of the pre-design investigation soil and groundwater sampling activities was submitted to the EPA.

The current estimate of future liability at this site includes only our estimated share of the costs of implementing the interim remedial action under the IROD. We are unable to reasonably estimate our final share of the total costs associated with the interim or final

remediation at the site, although such amounts may be material to any one quarter's or one year’s results of operations in the future. We do not expect the total future costs to have a material adverse effect on our liquidity or financial condition as the cash payments may be made over many years.

Summary of Financial Position

Total liabilities of $4.6 million and $4.1 million as of June 30, 2026 and December 31, 2025, respectively, were recorded for environmental matters that we consider probable and for which a reasonable estimate of the probable liability could be made. As of June 30, 2026 and December 31, 2025, environmental liabilities of $4.4 million and $4.1 million, respectively, were reflected within other long-term liabilities on the Condensed Consolidated Balance Sheets. As of June 30, 2026, environmental liabilities of $0.2 million were reflected within other current liabilities on the Condensed Consolidated Balance Sheets. During the three and six months ended June 30, 2026, we recorded additional reserves for potential environmental liabilities of $0.5 million and $0.6 million, respectively, as a component of SG&A expenses on our Condensed Consolidated Statements of Earnings and Comprehensive Income. During the three and six months ended June 30, 2025, we did not record any additional reserves for potential environmental liabilities.

Where existing data is sufficient to estimate the liability, that estimate has been used; where only a range of probable liabilities is available and no amount within that range is more likely than any other, the lower end of the range has been used. As assessments and remediation activities progress at each site, these liabilities are reviewed to reflect new information as it becomes available and adjusted to reflect amounts actually incurred and paid. These liabilities are undiscounted.

The estimated environmental liabilities above do not take into account any claims for additional recoveries from insurance or third parties. It is our policy to record insurance recoveries as assets on the Condensed Consolidated Balance Sheets when realizable. We incur costs to pursue environmental insurance recoveries, which are expensed as incurred.

Actual costs to be incurred at identified sites may vary from our estimates. Based on our knowledge of the identified sites, it is not possible to reasonably estimate future costs in excess of amounts already recognized.

OTHER CLAIMS

From time to time, we are involved in other various lawsuits, claims, proceedings, disputes, inquiries, investigations and other legal matters that arise in the ordinary course of business, including matters involving our products, intellectual property, contracts, employees, relationships with suppliers, relationships with distributors, other customers or end users, relationships with competitors, compliance with laws, statutes and regulations and other matters. In connection with those matters, and in addition to our defenses to them, we may have rights of indemnity, contribution or reimbursement from other parties or coverage under applicable insurance policies. When applicable and appropriate, we will seek indemnity, contribution or reimbursement from other parties and pursue coverage and recoveries under those policies, but we are unable to predict the outcome of those demands. While complete assurance cannot be given to the outcome of any proceedings relating to these matters, including the success of our defenses, we do not believe that any current claims, individually or in the aggregate, will have a material adverse effect on our financial condition, liquidity or results of operations.