Armstrong World Industries, Inc. ("AWI") is a Pennsylvania corporation incorporated in 1891.

This discussion should be read in conjunction with the financial statements, the accompanying notes, the cautionary note regarding forward-looking statements and risk factors included in this Form 10-K.

Overview

We are a leading global producer of flooring products and ceiling systems for use primarily in the construction and renovation of residential, commercial and institutional buildings. We design, manufacture and sell flooring products (primarily resilient and wood) and ceiling systems (primarily mineral fiber, fiberglass and metal) around the world.

In response to economic conditions during 2012, we closed two previously idled facilities: an engineered wood production facility in Statesville, NC, and a Building Products plant in Mobile, AL. Additionally, during the third quarter of 2012, we sold the assets of our wood flooring distribution (Patriot) and cabinets businesses. As of December 31, 2012, we operated 32 manufacturing plants in eight countries, including 20 plants located throughout the U.S.

Through Worthington Armstrong Venture ("WAVE"), our joint venture with Worthington Industries, Inc., we also have an interest in eight additional plants in six countries that produce suspension system (grid) products for our ceiling systems.

We report our financial results through the following segments: Building Products, Resilient Flooring, Wood Flooring, and Unallocated Corporate. See "Results of Operations" and "Reportable Segment Results" for additional financial information on our consolidated company and our segments.

Factors Affecting Revenues

For information on our segments' 2012 net sales by geography, see Note 3 to the Consolidated Financial Statements included in this Form 10-K.

Markets. We compete in building material markets around the world. The majority of our sales are in North America and Europe. We closely monitor macroeconomic trends that affect our business, including Gross Domestic Product, the Architecture Billings Index and the Consumer Confidence Index. During 2012, these macroeconomic benchmarks showed mixed results. In addition, we noted several factors and trends within our markets that directly affected our business performance during 2012, including:

North America

We noted softness in commercial markets, particularly education and healthcare as public spending remained constrained. In addition, we saw some regional weakness in the office market. These trends impacted both our Building Products and Resilient Flooring businesses, but with greater impact on Resilient Flooring as the majority of our commercial sales in Resilient Flooring originate from the education and healthcare markets.

We experienced mixed results in our residential markets as we saw continued improvements in builder activity while renovation activity remained soft. These trends impacted our Resilient and Wood Flooring businesses.

Europe

The overwhelming majority of our sales in Europe are to commercial markets in sectors dependent on public spending. Continued softness in commercial sectors, such as education and healthcare, and weak currency contributed significantly to sharp declines in Central and Western Europe, while Eastern European markets grew.

Management's Discussion and Analysis of Financial Condition and Results of Operations

Pacific Rim

Our markets in China experienced mixed results. The office sector remained soft while the education and healthcare markets grew. A continued soft commercial construction market impacted our Resilient Flooring and Building Products businesses in Australia.

Pricing Initiatives. We periodically modify prices in each of our business segments in response to changes in costs for raw materials and energy, and to market conditions and the competitive environment. In certain cases, realized price increases are less than the announced price increases because of competitive reactions and changing market conditions. We estimate that pricing actions increased our 2012 total consolidated net sales by approximately $27 million compared to 2011.

We have announced price increases in our ceilings and grid businesses in the Americas and in Europe that are effective in the first quarter of 2013. In response to rising lumber costs, we have also announced a price increase in our wood flooring business that is also effective in the first quarter of 2013. If raw material prices continue at, or rise from, current levels, additional pricing actions may be implemented.

Mix. Each of our businesses offers a wide assortment of products that are differentiated by style, design and performance attributes. Pricing and margins for products within the assortment vary. Changes in the relative quantity of products purchased at the different price points can impact year-to-year comparisons of net sales and operating income. We estimate that mix improvements increased our total consolidated net sales by approximately $15 million in 2012, compared to 2011.

Factors Affecting Operating Costs

Operating Expenses. Our operating expenses are comprised of direct production costs (principally raw materials, labor and energy), manufacturing overhead costs, freight, costs to purchase sourced products and selling, general and administrative ("SG&A") expenses.

Our largest individual raw material expenditures are for lumber and veneers, PVC resins and plasticizers. Natural gas is also a significant input cost. Fluctuations in the prices of these inputs are generally beyond our control and have a direct impact on our financial results. In 2012, the costs for raw materials, sourced products and energy negatively impacted operating income by approximately $1 million, compared to 2011.

During 2011, we incurred approximately $15 million of net costs related to the renegotiation of seven expiring collective bargaining agreements covering six plants (Beverly, WV, Oneida, TN, Marietta, PA, Lancaster, PA, Pensacola, FL, and Macon, GA) and the related lockout of our unionized employees at our Marietta, PA plant. We also incurred approximately $4 million of additional net costs in the first quarter of 2012 related to the contract settlement with our employees at the Marietta, PA plant.

We are committed to augmenting margin expansion through cost elimination. Through manufacturing footprint reductions and aggressive application of projects designed to standardize, simplify and eliminate SG&A programs and policies, we undertook an effort to remove at least $200 million of manufacturing and SG&A costs by the end of 2012. Toward this end, we achieved $35 million of cost savings in 2010, $115 million in savings in 2011, and delivered another $63 million of cost savings during 2012. We recorded expenses of approximately $28 million for these initiatives in 2012 and $36 million in 2011. During the first quarter of 2012, we decided to close our previously idled Building Products plant in Mobile, AL. We also decided in the fourth quarter of 2012 to close our previously idled engineered wood plant in Statesville, NC. We will continue to evaluate the efficiency of our manufacturing footprint and may take additional actions in support of our cost and standardization initiatives. The charges associated with our cost reduction initiatives may include severance and related termination benefits, fixed asset write-downs, asset impairments and accelerated depreciation and could be material to our financial statements.

Intangible Asset Impairments. During the fourth quarter of 2010, we recorded non-cash impairment charges of $22.4 million to reduce the carrying amount of our Wood Flooring trademarks to their estimated fair value. There were no impairment charges recorded related to these trademarks in 2012 or 2011. See Note 12 to the Consolidated Financial Statements for more information.

Management's Discussion and Analysis of Financial Condition and Results of Operations

See also "Results of Operations" for further discussion of other significant items affecting operating costs.

Employees

As of December 31, 2012, we had approximately 8,500 full-time and part-time employees worldwide, compared to approximately 9,100 employees as of December 31, 2011. The decrease is primarily due to the divestiture of our cabinets business (approximately 800 employees), partially offset by crews added in our wood flooring plants and in our China plants under construction. During 2012, we negotiated a collective bargaining agreement covering approximately 100 employees at a resilient flooring plant.

CRITICAL ACCOUNTING ESTIMATES

In preparing our consolidated financial statements in accordance with U.S. generally accepted accounting principles ("GAAP"), we are required to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. We evaluate our estimates and assumptions on an on-going basis, using relevant internal and external information. We believe that our estimates and assumptions are reasonable. However, actual results may differ from what was estimated and could have a significant impact on the financial statements.

We have identified the following as our critical accounting estimates. We have discussed these critical accounting estimates with our Audit Committee.

U.S. Pension Credit and Postretirement Benefit Costs - We maintain pension and postretirement plans throughout the world, with the most significant plans located in the U.S. Our defined benefit pension and postretirement benefit costs are developed from actuarial valuations. These valuations are calculated using a number of assumptions. Each assumption represents management's best estimate of the future. The assumptions that have the most significant impact on reported results are the discount rate, the estimated long-term return on plan assets and the estimated inflation in health care costs. These assumptions are generally updated annually.

The discount rate is used to determine retirement plan liabilities and to determine the interest cost component of net periodic pension and postretirement cost. Management utilizes the Aon Hewitt AA only above median yield curve, which is a hypothetical AA yield curve comprised of a series of annualized individual discount rates, as the primary basis for determining the discount rate. As of December 31, 2012 and 2011, we assumed discount rates of 3.95% and 4.85%, respectively, for the U.S. defined benefit pension plans. As of December 31, 2012, we assumed a discount rate of 3.75% compared with a discount rate of 4.75% as of December 31, 2011 for the U.S. postretirement plans. The effects of the change in discount rate will be amortized into earnings as described below. Absent any other changes, a one-quarter percentage point decrease in the discount rates for the U.S. pension and postretirement plans would decrease 2013 operating income by $5.4 million and a one-quarter percentage point increase in the discount rates would increase 2013 operating income by $5.2 million.

We have two U.S. defined benefit pension plans, a qualified funded plan and a nonqualified unfunded plan. For the qualified funded plan, the expected long-term return on plan assets represents a long-term view of the future estimated investment return on plan assets. This estimate is determined based on the target allocation of plan assets among asset classes and input from investment professionals on the expected performance of the asset classes over 10 to 20 years. Historical asset returns are monitored and considered when we develop our expected long-term return on plan assets. An incremental component is added for the expected return from active management based both on the plan's experience and on historical information obtained from the plan's investment consultants. These forecasted gross returns are reduced by estimated management fees and expenses, yielding a long-term rate of return of 6.25% per annum for 2013. The expected asset return assumption is based upon a long-term view; therefore, we do not expect to see frequent changes from year to year based on positive or negative actual performance in a single year. Over the 10 year period ended December 31, 2012, the annualized return was approximately 9.2% compared to an average expected return of 7.8%. The actual return on plan assets achieved for 2012 was 15.0%. The difference between the actual and expected rate of return on plan assets will be amortized into earnings as described below.

Management's Discussion and Analysis of Financial Condition and Results of Operations

The expected long-term return on plan assets used in determining our 2012 U.S. pension credit was 6.50%. We have assumed a return on plan assets during 2013 of 6.25%. The decrease reflects a planned change in our asset allocations. The 2013 expected return on assets was calculated in a manner consistent with 2012. A one-quarter percentage point increase or decrease in this assumption would increase or decrease 2013 operating income by approximately $5.5 million.

Contributions to the unfunded plan were $4.0 million in 2012 and were made on a monthly basis to fund benefit payments. We estimate the 2013 contributions will be approximately $3.8 million. See Note 19 to the Consolidated Financial Statements for more information.

The estimated inflation in health care costs represents a long-term view (5-10 years) of the expected inflation in our postretirement health care costs. We separately estimate expected health care cost increases for pre-65 retirees and post-65 retirees due to the influence of Medicare coverage at age 65, as illustrated below:

                         Assumptions                                    Actual
             Post 65        Pre 65        Overall        Post 65        Pre 65         Overall
     2011         8.5 %         8.6 %          8.5 %           11 %           2 %             8 %
     2012         8.1 %         8.1 %          8.1 %          (13 %)         (1 %)           (9 %)
     2013         7.8 %         7.6 %          7.7 %

The difference between the actual and expected health care costs is amortized into earnings as described below. As of December 31, 2012, health care cost increases are estimated to decrease ratably until 2019, after which they are estimated to be constant at 5%. A one percentage point increase in the assumed health care cost trend rate would reduce 2013 operating income by $1.5 million, while a one percentage point decrease in the assumed health care cost trend rate would increase 2013 operating income by $1.4 million. See Note 19 to the Consolidated Financial Statements for more information.

Actual results that differ from our various pension and postretirement plan estimates are captured as actuarial gains/losses. When certain thresholds are met, the gains and losses are amortized into future earnings over the expected remaining service period of plan participants, which is approximately eight years for our U.S. pension plans and our U.S. postretirement plans. Changes in assumptions could have significant effects on earnings in future years.

We recognized an increase in net actuarial losses related to our U.S. pension benefit plans of $43.1 million in 2012. Our accumulated losses increased primarily due to changes in actuarial assumptions (most significantly a 90 basis point decline in the discount rate), partially offset by gains due to better than expected asset performance. The $43.1 million actuarial loss due to our U.S. pension plans is reflected as a component of other comprehensive income in our Consolidated Statement of Earnings and Comprehensive Income along with actuarial losses from our foreign pension plans and actuarial gains from our U.S. postretirement benefit plans.

Impairments of Long-Lived Tangible and Intangible Assets - Our indefinite-lived intangibles are primarily trademarks and brand names, which are integral to our corporate identity and expected to contribute indefinitely to our corporate cash flows. Accordingly, they have been assigned an indefinite life. We conduct our annual impairment test for non-amortizable intangible assets during the fourth quarter, although we conduct interim impairment tests if events or circumstances indicate the asset might be impaired. We conduct impairment tests for tangible assets and amortizable intangible assets when indicators of impairment exist, such as operating losses and/or negative cash flows. If an indication of impairment exists, we compare the carrying amount of the asset group to the estimated undiscounted future cash flows expected to be generated by the assets. The estimate of an asset group's fair value is based on discounted future cash flows expected to be generated by the asset group, or based on management's estimated exit price assuming the assets could be sold in an orderly transaction between

Management's Discussion and Analysis of Financial Condition and Results of Operations

market participants or estimated salvage value if no sale is assumed. If the fair value is less than the carrying value of the asset group, we record an impairment charge equal to the difference between the fair value and carrying value of the asset group.

The principal assumptions utilized in our impairment tests for definite-lived intangible assets include operating profit adjusted for depreciation and amortization. The principal assumptions utilized in our impairment tests for indefinite-lived intangible assets include revenue growth rate, discount rate and royalty rate. Revenue growth rate and operating profit assumptions are derived from those utilized in our operating plan and strategic planning processes. The discount rate assumption is calculated based upon an estimated weighted average cost of equity which reflects the overall level of inherent risk and the rate of return a market participant would expect to achieve. Methodologies used for valuing our intangible assets did not change from prior periods.

The cash flow estimates used in applying our impairment tests are based on management's analysis of information available at the time of the impairment test. Actual cash flows lower than the estimate could lead to significant future impairments. If subsequent testing indicates that fair values have declined, the carrying values would be reduced and our future statements of income would be affected.

There was no impairment charge in 2012 or 2011 related to intangible assets. During the fourth quarter of 2010 we recorded non-cash impairment charges of $22.4 million to reduce the carrying value of our Wood Flooring trademarks to their estimated fair value based on the results of our annual impairment test. The remaining carrying value of the Wood Flooring trademarks at December 31, 2012 and 2011 was $41.8 million and $42.0 million, respectively.

We tested the tangible assets within the following reporting units for impairment:

                     Reporting Unit                2012   2011
                     ABP Americas                   X      X
                     Resilient Flooring - Europe    X      X
                     Wood Flooring                  X      X

Based upon the impairment testing, the carrying value of the tangible assets for each of these asset groups was determined to be recoverable (except as discussed below) because the related undiscounted cash flows and/or fair value exceeded the carrying value of assets.

During the first quarter of 2012, we made the decision to permanently close a previously idled ceiling tile plant in Mobile, AL. As a result, we recorded a $4.6 million impairment charge for the buildings in cost of goods sold. The preliminary fair values were determined by management estimates and an independent valuation based on information available at that time (considered Level 2 inputs in the fair value hierarchy).

During the third quarter of 2012, we recorded a $17.5 million impairment charge to the value of the cabinets' assets to reflect the expected proceeds from the sale of the cabinets business, which was accounted for as a discontinued operation.

During the fourth quarter of 2012, we made the decision to permanently close a previously idled engineered wood flooring production facility in Statesville, NC. As a result, we recorded a $0.6 million impairment charge for the buildings in cost of goods sold. The preliminary fair values were determined by management estimates and an independent valuation based on information available at that time (considered Level 2 inputs in the fair value hierarchy).

We recorded an asset impairment charge of $2.2 million in the third quarter of 2011 in SG&A expense for a European Resilient Flooring office building. The fair value was determined by management estimates of market prices based upon information available at that time, including offers received from potential buyers of the property (considered Level 3 inputs in the fair value hierarchy).

The remaining carrying value of tangible assets within the European Resilient Flooring business was $90.6 million as of December 31, 2012, with land and buildings representing the significant majority. Material

Management's Discussion and Analysis of Financial Condition and Results of Operations

uncertainties that could lead to a future material impairment charge include the level of European commercial construction and renovation activity.

During the fourth quarter of 2011, we recorded asset impairment charges of $1.1 million in SG&A expense for two previously occupied manufacturing facilities. We have been actively pursuing a sale of both facilities. The fair values were determined by management estimates and independent market valuations based on information available at that time. The valuation information included sales of similar facilities and estimates of market prices (considered Level 2 inputs in the fair value hierarchy) for these assets.

During the second quarter of 2010, we recorded an asset impairment charge of $2.1 million in SG&A expense for a European Resilient Flooring warehouse facility due to the decline in the commercial property sector. The fair value was determined by management estimates of market prices available at that time. This data included sales and leases of comparable properties within similar real estate markets (considered Level 3 inputs in the fair value hierarchy). We sold the warehouse in the first quarter of 2011.

During 2010, management decided to exit our corporate flight operations. As a result, we recorded a $6.1 million impairment charge in SG&A expense for corporate aircraft in 2010. The fair values were determined by management estimates and an independent valuation based on information available at that time. The valuation information included sales of similar equipment and estimates of market prices (considered Level 2 inputs in the fair value hierarchy) for these assets. We sold the corporate aircraft in the fourth quarter of 2010.

We cannot predict the occurrence of certain events that might lead to material impairment charges in the future. Such events may include, but are not limited to, the impact of economic environments, particularly related to the commercial and residential construction industries, material adverse changes in relationships with significant customers, or strategic decisions made in response to economic and competitive conditions.

See Notes 3 and 12 to the Consolidated Financial Statements for further information.

Income Taxes - Our effective tax rate is primarily determined based on our pre-tax income and the statutory income tax rates in the jurisdictions in which we operate. The effective tax rate also reflects the tax impacts of items treated differently for tax purposes than for financial reporting purposes. Some of these differences are permanent, such as expenses that are not deductible in our tax returns, and some differences are temporary, reversing over time, such as depreciation expense. These temporary differences create deferred income tax assets and liabilities. Deferred income tax assets are also recorded for operating loss, capital loss, alternative minimum tax credit and foreign tax credit carryforwards.

Deferred income tax assets and liabilities are recognized by applying enacted tax rates to temporary differences that exist as of the balance sheet date. We reduce the carrying amounts of deferred tax assets by a valuation allowance if, based on the available evidence, it is more likely than not that such assets will not be realized. The need to establish valuation allowances for deferred tax assets is assessed quarterly. In assessing the requirement for, and amount of, a valuation allowance in accordance with the more likely than not standard, we give appropriate consideration to all positive and negative evidence related to the realization of the deferred tax assets. This assessment considers, among other matters, the nature, frequency and severity of current and cumulative losses, forecasts of future profitability and foreign source income, the duration of statutory carryforward periods, and our experience with operating loss and tax credit carryforward expirations. A history of cumulative losses is a significant piece of negative evidence used in our assessment. If a history of cumulative losses is incurred for a tax jurisdiction, forecasts of future profitability are not used as positive evidence related to the realization of the deferred tax assets in the assessment.

As of December 31, 2012, we have recorded valuation allowances totaling $205.5 million for various federal, state and foreign deferred tax assets. While we have considered future taxable income in assessing the need for the valuation allowances based on our best available projections, if these estimates

Management's Discussion and Analysis of Financial Condition and Results of Operations

and assumptions change in the future or if actual results differ from our projections, we may be required to adjust our valuation allowances accordingly. Such adjustments could be material to our Consolidated Financial Statements.

As further described in Note 17 to the Consolidated Financial Statements, our Consolidated Balance Sheet as of December 31, 2012 includes net deferred income tax assets of $373 million. Included in this amount are deferred federal income tax assets for foreign tax credit carryforwards of $119.1 million, state net operating loss deferred income tax assets of $51.7 million, and foreign net operating loss deferred tax assets of $166.9 million. We have established valuation allowances in the amount of $205.5 million consisting of $16.0 million for federal capital loss carryovers and statutorily limited operating loss carryovers, $16.2 million for state deferred tax assets, primarily operating loss carryovers, and $173.3 million for foreign deferred tax assets, primarily foreign operating loss carryovers.

The federal foreign tax credits carryforwards arose primarily as a result of the payment of intercompany dividends from our foreign affiliates from earnings . . .