Form 8-K

8-K — WESTLAKE CORP

Accession: 0001262823-26-000019

Filed: 2026-05-05

Period: 2026-05-05

CIK: 0001262823

SIC: 2860 (INDUSTRIAL ORGANIC CHEMICALS)

Item: Results of Operations and Financial Condition

Item: Regulation FD Disclosure

Item: Financial Statements and Exhibits

Documents

8-K — wlk-20260505.htm (Primary)

EX-99.1 (ex991_20260331earningsrele.htm)

EX-99.2 (ex992_20260331wlkearning.htm)

GRAPHIC (ex992_20260331wlkearning001.jpg)

GRAPHIC (ex992_20260331wlkearning002.jpg)

GRAPHIC (ex992_20260331wlkearning003.jpg)

GRAPHIC (ex992_20260331wlkearning004.jpg)

GRAPHIC (ex992_20260331wlkearning005.jpg)

GRAPHIC (ex992_20260331wlkearning006.jpg)

GRAPHIC (ex992_20260331wlkearning007.jpg)

GRAPHIC (ex992_20260331wlkearning008.jpg)

GRAPHIC (ex992_20260331wlkearning009.jpg)

GRAPHIC (ex992_20260331wlkearning010.jpg)

GRAPHIC (ex992_20260331wlkearning011.jpg)

GRAPHIC (ex992_20260331wlkearning012.jpg)

GRAPHIC (ex992_20260331wlkearning013.jpg)

GRAPHIC (ex992_20260331wlkearning014.jpg)

GRAPHIC (ex992_20260331wlkearning015.jpg)

XML — IDEA: XBRL DOCUMENT (R1.htm)

8-K

8-K (Primary)

Filename: wlk-20260505.htm · Sequence: 1

wlk-20260505

false000126282300012628232026-05-052026-05-050001262823us-gaap:CommonStockMember2026-05-052026-05-050001262823wlk:OnePointSixTwoFivePercentageSeniorNotesDueTwentyTwentyNineMemberDomain2026-05-052026-05-05

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of

the Securities Exchange Act of 1934

Date of Report (date of earliest event reported): May 5, 2026

Westlake Corporation

(Exact name of registrant as specified in its charter)

Delaware 001-32260 76-0346924

(State or other jurisdiction

of incorporation) (Commission File Number) (I.R.S. Employer

Identification No.)

2801 Post Oak Boulevard, Suite 600

Houston, Texas 77056

(Address of principal executive offices) (Zip Code)

Registrant's telephone number, including area code: (713) 960-9111

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class Trading Symbol(s) Name of each exchange on which registered

Common Stock, $0.01 par value WLK The New York Stock Exchange

1.625% Senior Notes due 2029 WLK29 The New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ◻

Item 2.02. Results of Operations and Financial Condition.

On May 5, 2026, Westlake Corporation (the "Company"), issued a press release announcing its 2026 first quarter results. A copy of the press release is furnished with this Current Report as Exhibit 99.1.

The information furnished pursuant to this Current Report, including Exhibit 99.1, shall not be deemed to be "filed" for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, and will not be incorporated by reference into any registration statement filed by Westlake Corporation under the Securities Act of 1933, as amended, unless specifically identified as being incorporated therein.

Item 7.01. Regulation FD Disclosure.

The Company is holding a conference call on May 5, 2026 to discuss its 2026 first quarter results. Information about the call can be found in the press release furnished with this Current Report as Exhibit 99.1. In addition, the Company made available an investor presentation regarding its 2026 first quarter results, which is furnished with this Current Report as Exhibit 99.2.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

The following exhibits are furnished herewith:

99.1 Press release issued on May 5, 2026.

99.2 Investor Presentation.

104 The cover page from this Current Report on Form 8-K, formatted in Inline XBRL.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

WESTLAKE CORPORATION

Date: May 5, 2026 By:

/S/ JEAN-MARC GILSON

Jean-Marc Gilson

President, Chief Executive Officer and Director

EX-99.1

Filename: ex991_20260331earningsrele.htm · Sequence: 2

Document

EXHIBIT 99.1

WESTLAKE CORPORATION

Contact—(713) 960-9111

Investors—Steve Bender

Media—L. Benjamin Ederington

Westlake Corporation Reports First Quarter 2026 Results

HOUSTON--(BUSINESS WIRE)--Westlake Corporation (NYSE: WLK) (the "Company" or "Westlake") today announced first quarter 2026 results.

SUMMARY FINANCIAL HIGHLIGHTS (in millions of dollars, except per share data and percentages)

Three Months Ended March 31, 2026 Three Months Ended December 31, 2025 Three Months Ended March 31, 2025

Westlake Corporation

Net sales $ 2,652 $ 2,533 $ 2,846

Loss from operations

$ (172) $ (671) $ (32)

Net loss attributable to Westlake Corporation

$ (169) $ (544) $ (40)

Diluted loss per common share

$ (1.31) $ (4.22) $ (0.31)

Identified Items (1)

$ 85 $ 511 $ 7

Net loss attributable to Westlake Corporation excl. Identified Items

$ (100) $ (131) $ (33)

Diluted loss per common share excl. Identified Items

$ (0.77) $ (1.02) $ (0.26)

EBITDA $ 150 $ (315) $ 288

EBITDA excl. Identified Items

$ 235 $ 196 $ 295

EBITDA margin (2)

9% 8% 10%

Housing and Infrastructure Products ("HIP") Segment

Net sales $ 993 $ 901 $ 996

Income from operations $ 56 $ 66 $ 148

EBITDA $ 118 $ 130 $ 203

Identified Items (1)

$ 68 $ 16 $ —

EBITDA excl. Identified Items $ 186 $ 146 $ 203

EBITDA margin (2)

19% 16% 20%

Performance and Essential Materials ("PEM") Segment

Net sales $ 1,659 $ 1,632 $ 1,850

Loss from operations

$ (211) $ (717) $ (163)

EBITDA $ 19 $ (450) $ 73

Identified Items (1)

$ 17 $ 495 $ 7

EBITDA excl. Identified Items

$ 36 $ 45 $ 80

EBITDA margin (2)

2% 3% 4%

______________________________

(1)For the three months ended March 31, 2026, Identified Items include a $67 million charge to settle certain litigation involving direct purchasers of PVC pipe and fittings and $18 million of charges related to previously announced facility shutdowns. For the three months ended December 31, 2025, Identified Items include $495 million of PEM shutdown charges and $16 million for HIP restructuring charges. For the three months ended March 31, 2025, Identified Items represent $7 million of charges related to previously announced facility shutdowns.

(2)Excludes Identified Items.

BUSINESS HIGHLIGHTS

In the first quarter of 2026, Westlake reported net sales of $2.7 billion, a net loss of $169 million, or $1.31 per share, and EBITDA (earnings before interest expense, income taxes, depreciation and amortization) of $150 million. Earnings in the first quarter were impacted by the previously announced $67 million settlement of certain litigation involving direct purchasers of PVC pipe and fittings in the United States and $18 million of charges related to previously announced facility shutdowns, including epoxy, North American chlorovinyls and styrene, and cost saving actions for a combined $85 million impact (the "Identified Items"). Excluding the effects of the Identified Items, the net loss in the first quarter of 2026 was $100 million, or $0.77 per share, and EBITDA was $235 million.

Compared to the fourth quarter of 2025, Westlake's first quarter of 2026 sales volume increased 6% (excluding sales attributable to plant closures and acquisitions) while average sales price increased 1%. Housing and Infrastructure Products sales increased 10%, driven by 10% sales volume growth (excluding the ACI acquisition) that more than offset a 5% decline in average sales price. Performance and Essential Materials sales increased 2% over the same period of time due to a 3% increase in average sales price and a 3% increase in sales volume (excluding plant shutdowns) that was partially offset by a 5% sales impact from plant shutdowns.

EXECUTIVE COMMENTARY

"The first quarter of 2026 began to reflect our cost reduction initiatives announced in 2025. Late in the first quarter we began to see margin improvement in the PEM segment as a result of the Iranian conflict. Our HIP segment saw gains in Pipe and Fittings sales volumes driven by continued strength in infrastructure spending, which was more than offset by the subdued North American residential construction activity and lower average sales prices," said Jean‑Marc Gilson, President and Chief Executive Officer.

"Since the closure of the Strait of Hormuz in March, PVC resin and polyethylene sales prices have risen significantly, driven by a steepening of the global cost curve as a result of sharply higher global feedstock and energy prices. At the same time, North American natural gas costs have declined from earlier-year levels due to more favorable weather conditions. While the duration and severity of the impact on global feedstock and energy markets from supply chain disruptions remain uncertain, we expect these factors to provide a meaningful benefit to PEM's margins through at least the summer of 2026. We expect HIP sales volume to be supported by continued infrastructure spending, including strong demand from new data centers, although interest rates and increased building costs are likely to keep home affordability as a headwind to sales volume growth. Finally, in addition to the pricing and margin benefits of a steeper global cost curve, we anticipate further earnings improvement in the coming quarters as we continue to execute against our three‑pillar profitability improvement plan," Mr. Gilson concluded.

RESULTS

Consolidated Results

(Unless otherwise noted the financial numbers below exclude the effects of the Identified Items)

For the three months ended March 31, 2026, the Company reported a quarterly net loss of $100 million, or $0.77 per share, on net sales of $2.7 billion compared to the net loss of $131 million reported in the fourth quarter of 2025. Sequentially, earnings benefited from the ACI acquisition and higher HIP sales volume, which were partially offset by the impact of higher natural gas costs.

EBITDA of $235 million for the first quarter of 2026 decreased by $60 million compared to first quarter 2025 EBITDA of $295 million. First quarter 2026 EBITDA increased by $39 million compared to fourth quarter 2025 EBITDA of $196 million.

Reconciliations of non-GAAP financial measures used in this press release (including EBITDA and measures that exclude the effects of the Identified Items) to the most directly comparable GAAP measure can be found in the financial schedules at the end of this press release.

Cash, Investments and Debt

Net cash used for operating activities was $94 million for the first quarter of 2026 and capital expenditures were $209 million. As of March 31, 2026, cash, cash equivalents and fixed-income investments were $2.5 billion and total debt was $5.6 billion.

Housing and Infrastructure Products Segment

(Unless otherwise noted the financial numbers below exclude the effects of the Identified Items)

For the first quarter of 2026, Housing and Infrastructure Products income from operations of $124 million decreased by $24 million as compared to the first quarter of 2025. The year-over-year decrease was the result of lower average sales price and margins, particularly in Pipe & Fittings, and lower sales volume (excluding sales attributable to the ACI acquisition), particularly in Building Products.

Sequentially, Housing and Infrastructure Products income from operations increased by $42 million as compared to the fourth quarter of 2025. This increase in income from operations versus the prior quarter was primarily due to seasonally higher sales volume and sales attributable to the ACI acquisition.

Performance and Essential Materials Segment

(Unless otherwise noted the financial numbers below exclude the effects of the Identified Items)

For the first quarter of 2026, Performance and Essential Materials loss from operations was $194 million as compared to the first quarter of 2025's loss from operations of $156 million due to a 3% decline in average sales price that was partially offset by margin benefits from footprint optimization and cost saving actions. Performance Materials net sales of $1.0 billion in the first quarter of 2026 decreased by $53 million primarily due to lower average sales price for polyethylene and PVC resin and lower PVC resin sales volume due to footprint optimization actions. Essential Materials net sales of $656 million decreased by $138 million from the first quarter of 2025 primarily due to lower chlorine and caustic soda sales volume.

Sequentially, Performance and Essential Materials loss from operations for the first quarter of 2026 decreased by $28 million as compared to the fourth quarter of 2025. This improvement in loss from operations versus the prior quarter was primarily due to a higher average sales price, particularly for polyethylene.

iii

Forward-Looking Statements

The statements in this release and the related teleconference relating to matters that are not historical facts, including statements regarding our outlook for the performance of our business segments and future earnings, global macroeconomic conditions and their effects on us and our customers, expectations regarding interest rates and building costs, trends in the global cost curve and any associated pricing and margin benefits, industrial and manufacturing activity in our target markets, including infrastructure spending and demand for data centers, growth in our customers' businesses and their dependence on our products, the effects of the conflict in Iran on us, our competitors and global supply chains, future global trading policy and relationships, housing demand and residential construction activity, raw material costs, fluctuations in energy and feedstock prices, our ability to execute against our profitability improvement plan and the effects of our optimization initiatives (including anticipated cost savings), our market position and the strength of our brands, the benefits of a diversified and integrated business model, our ability to maintain cost advantages and global demand for our products are forward-looking statements.

These forward-looking statements are subject to significant risks and uncertainties. Actual results could differ materially, based on factors including, but not limited to: general economic and business conditions; the cyclical nature of the chemical and building products industries; the availability, cost and volatility of raw materials and energy; uncertainties associated with the United States, European and worldwide economies, including those due to political tensions and conflict in the Middle East, Russia and Ukraine and elsewhere; uncertainties associated with pandemic infectious diseases; uncertainties associated with climate change; the potential impact on demand for ethylene, polyethylene and polyvinyl chloride due to initiatives such as recycling and customers seeking alternatives to polymers; current and potential governmental regulatory actions in the United States and other countries; industry production capacity and operating rates; the supply/demand balance for Westlake's products; competitive products and pricing pressures; instability in the credit and financial markets; access to capital markets; terrorist acts; operating interruptions; changes in laws and regulations, including trade policies and tariffs; the effects of government shutdowns; technological developments; information systems failures and cyberattacks; foreign currency exchange risks; our ability to implement our business strategies; creditworthiness of our customers; the effects and results of litigation and settlements of litigation; and other risk factors. For more detailed information about the factors that could cause actual results to differ materially, please refer to Westlake's Annual Report on Form 10-K for the year ended December 31, 2025, which was filed with the SEC in February 2026.

Use of Non-GAAP Financial Measures

This release makes reference to certain "non-GAAP" financial measures, such as EBITDA, free cash flow and other measures that exclude the effects of the Identified Items, as defined in Regulation G of the U.S. Securities Exchange Act of 1934, as amended. For this purpose, a non-GAAP financial measure is generally defined by the Securities and Exchange Commission (SEC) as a numerical measure of a registrant's historical or future financial performance, financial position or cash flows that (1) excludes amounts, or is subject to adjustments that have the effect of excluding amounts, that are included in the most directly comparable measure calculated and presented in accordance with GAAP in the statement of operations, balance sheet or statement of cash flows (or equivalent statements) of the registrant; or (2) includes amounts, or is subject to adjustments that have the effect of including amounts, that are excluded from the most directly comparable measure so calculated and presented. We report our financial results in accordance with U.S. generally accepted accounting principles (U.S. GAAP), but believe that certain non-GAAP financial measures, such as EBITDA, free cash flow and measures that exclude the effects of the Identified Items, provide useful supplemental information to investors regarding the underlying business trends and performance of the Company's ongoing operations and are useful for period-over-period comparisons of such operations. These non-GAAP financial measures should be considered as a supplement to, and not as a substitute for or superior to, the financial measures prepared in accordance with U.S. GAAP. A reconciliation of (i) net loss, loss from operations and net cash provided by (used for) operating activities to EBITDA, and (ii) net cash provided by (used for) operating activities to free cash flow and (iii) other measures reflecting adjustments for the effects of the Identified Items can be found in the financial schedules at the end of this press release.

About Westlake

Celebrating 40 years of operations in 2026, Westlake is a global manufacturer and supplier of materials and innovative products that enhance life every day. Headquartered in Houston, with operations in Asia, Europe and North America, we provide the building blocks for vital solutions — from housing and construction, to packaging and healthcare, to automotive and consumer goods. For more information, visit the Company's web site at www.westlake.com.

Westlake Corporation Conference Call Information:

A conference call to discuss Westlake Corporation's first quarter 2026 results will be held Tuesday, May 5, 2026 at 11:00 AM Eastern Time (10:00 AM Central Time). To access the conference call, it is necessary to pre-register at https://register-conf.media-server.com/register/BI34ea020237b448069214d7ccf868ece8. Once registered, you will receive a phone number and unique PIN number.

A replay of the conference call will be available beginning two hours after its conclusion. The conference call and replay will be available via webcast at https://edge.media-server.com/mmc/p/p33g6sjv/.

WESTLAKE CORPORATION

CONSOLIDATED STATEMENTS OF OPERATIONS

(Unaudited)

Three Months Ended March 31,

2026 2025

(in millions of dollars, except per share data and share amounts)

Net sales $ 2,652 $ 2,846

Cost of sales 2,540 2,614

Gross profit 112 232

Selling, general and administrative expenses 236 227

Amortization of intangibles 30 30

Restructuring, transaction and integration-related costs 18 7

Loss from operations

(172) (32)

Interest expense (56) (39)

Other income, net 38 37

Loss before income taxes

(190) (34)

Provision for (benefit from) income taxes

(33) 1

Net loss (157) (35)

Net income attributable to noncontrolling interests 12 5

Net loss attributable to Westlake Corporation

$ (169) $ (40)

Loss per common share attributable to Westlake Corporation:

Basic $ (1.31) $ (0.31)

Diluted $ (1.31) $ (0.31)

Weighted average common shares outstanding:

Basic 127,992,500 128,308,537

Diluted 127,992,500 128,308,537

WESTLAKE CORPORATION

CONDENSED CONSOLIDATED BALANCE SHEETS

(Unaudited)

March 31,

2026 December 31,

2025

(in millions of dollars)

ASSETS

Current assets

Cash and cash equivalents $ 2,271 $ 2,724

Available-for-sale securities

205 204

Accounts receivable, net 1,690 1,504

Inventories 1,677 1,653

Prepaid expenses and other current assets 109 131

Total current assets 5,952 6,216

Property, plant and equipment, net 8,579 8,605

Other assets, net 5,176 5,140

Total assets $ 19,707 $ 19,961

LIABILITIES AND EQUITY

Current liabilities (accounts payable and accrued and other liabilities) $ 2,247 $ 2,273

Current portion of long-term debt, net

496 497

Long-term debt, net 5,074 5,087

Other liabilities 2,839 2,809

Total liabilities 10,656 10,666

Total Westlake Corporation stockholders' equity 8,547 8,792

Noncontrolling interests 504 503

Total equity 9,051 9,295

Total liabilities and equity $ 19,707 $ 19,961

vii

WESTLAKE CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(Unaudited)

Three Months Ended March 31,

2026 2025

(in millions of dollars)

Cash flows from operating activities

Net loss

$ (157) $ (35)

Adjustments to reconcile net loss to net cash provided by operating activities

Depreciation and amortization 284 283

Deferred income taxes 34 (1)

Net loss on disposition and others 9 12

Other balance sheet changes (264) (336)

Net cash used for operating activities (94) (77)

Cash flows from investing activities

Acquisition of business, net of cash acquired (62) —

Additions to investments in unconsolidated subsidiaries — (6)

Additions to property, plant and equipment (209) (248)

Proceeds from maturities and paydown of available-for-sale securities

33 —

Purchase of available-for-sale securities

(35) (183)

Other, net 2 3

Net cash used for investing activities (271) (434)

Cash flows from financing activities

Distributions to noncontrolling interests (10) (10)

Dividends paid (68) (68)

Repurchase of common stock for treasury — (30)

Other, net (4) (7)

Net cash used for financing activities (82) (115)

Effect of exchange rate changes on cash, cash equivalents and restricted cash (5) 4

Net decrease in cash, cash equivalents and restricted cash

(452) (622)

Cash, cash equivalents and restricted cash at beginning of period 2,740 2,935

Cash, cash equivalents and restricted cash at end of period $ 2,288 $ 2,313

viii

WESTLAKE CORPORATION

SEGMENT INFORMATION

(Unaudited)

Three Months Ended March 31,

2026 2025

(in millions of dollars)

Net external sales

Housing and Infrastructure Products

Housing Products $ 788 $ 838

Infrastructure Products 205 158

Total Housing and Infrastructure Products 993 996

Performance and Essential Materials

Performance Materials 1,003 1,056

Essential Materials 656 794

Total Performance and Essential Materials 1,659 1,850

Total reportable segments and consolidated

$ 2,652 $ 2,846

Income (loss) from operations

Housing and Infrastructure Products

$ 56 $ 148

Performance and Essential Materials (211) (163)

Total reportable segments (155) (15)

Corporate and other (17) (17)

Consolidated $ (172) $ (32)

Depreciation and amortization

Housing and Infrastructure Products

$ 60 $ 53

Performance and Essential Materials 221 227

Total reportable segments 281 280

Corporate and other 3 3

Consolidated $ 284 $ 283

Other income, net

Housing and Infrastructure Products

$ 2 $ 2

Performance and Essential Materials 9 9

Total reportable segments 11 11

Corporate and other 27 26

Consolidated $ 38 $ 37

WESTLAKE CORPORATION

RECONCILIATION OF EBITDA TO NET LOSS, LOSS FROM OPERATIONS AND

NET CASH PROVIDED BY (USED FOR) OPERATING ACTIVITIES (INCLUDING AND EXCLUDING IDENTIFIED ITEMS)

(Unaudited)

Three Months Ended December 31, Three Months Ended March 31,

2025 2026 2025

(in millions of dollars, except percentages)

Net cash provided by (used for) operating activities

$ 225 $ (94) $ (77)

Changes in operating assets and liabilities and other (975) (29) 41

Deferred income taxes 217 (34) 1

Net loss (533) (157) (35)

Add:

Identified Items, after-tax

413 69 7

Net loss excl. Identified Items

$ (120) $ (88) $ (28)

Net loss

(533) (157) (35)

Less:

Other income, net

59 38 37

Interest expense (51) (56) (39)

Benefit from (provision for) income taxes

130 33 (1)

Loss from operations

(671) (172) (32)

Add:

Identified Items, pre-tax

511 85 7

Loss from operations excl. Identified Items

(160) (87) (25)

Add:

Depreciation and amortization 297 284 283

Other income, net 59 38 37

EBITDA excl. Identified Items

196 235 295

Less:

Identified Items, pre-tax

511 85 7

EBITDA $ (315) $ 150 $ 288

Net external sales $ 2,533 $ 2,652 $ 2,846

Operating loss margin

(26)% (6)% (1)%

Operating loss margin excl. Identified Items

(6)% (3)% (1)%

EBITDA margin

(12)% 6% 10%

EBITDA margin excl. Identified Items

8% 9% 10%

WESTLAKE CORPORATION

RECONCILIATION OF DILUTED LOSS PER COMMON SHARE TO DILUTED LOSS PER COMMON SHARE EXCLUDING IDENTIFIED ITEMS

(Unaudited)

Three Months Ended December 31, Three Months Ended March 31,

2025 2026 2025

(per share data)

Diluted loss per common share attributable to Westlake Corporation

$ (4.22) $ (1.31) $ (0.31)

Add:

Loss per common share relating to Identified Items

3.20 0.54 0.05

Diluted loss per common share attributable to Westlake Corporation excl. Identified Items

$ (1.02) $ (0.77) $ (0.26)

WESTLAKE CORPORATION

RECONCILIATION OF FREE CASH FLOW TO NET CASH PROVIDED BY (USED FOR) OPERATING ACTIVITIES

(Unaudited)

Three Months Ended December 31, Three Months Ended March 31,

2025 2026 2025

(in millions of dollars)

Net cash provided by (used for) operating activities

$ 225 $ (94) $ (77)

Less:

Additions to property, plant and equipment 241 209 248

Free cash flow $ (16) $ (303) $ (325)

WESTLAKE CORPORATION

RECONCILIATION OF HIP SEGMENT EBITDA TO INCOME FROM OPERATIONS (INCLUDING AND EXCLUDING IDENTIFIED ITEMS)

(Unaudited)

Three Months Ended December 31, Three Months Ended March 31,

2025 2026 2025

(in millions of dollars, except percentages)

Housing and Infrastructure Products Segment

Income from operations

$ 66 $ 56 $ 148

Add:

Identified Items

16 68 —

Income from operations excl. Identified Items 82 124 148

Add:

Depreciation and amortization 61 60 53

Other income, net 3 2 2

EBITDA excl. Identified Items 146 186 203

Less:

Identified Items 16 68 —

EBITDA $ 130 $ 118 $ 203

Net external sales $ 901 $ 993 $ 996

Operating income margin

7% 6% 15%

Operating income margin excl. Identified Items 9% 12% 15%

EBITDA margin

14% 12% 20%

EBITDA margin excl. Identified Items 16% 19% 20%

xii

WESTLAKE CORPORATION

RECONCILIATION OF PEM SEGMENT EBITDA TO LOSS FROM OPERATIONS (INCLUDING AND EXCLUDING IDENTIFIED ITEMS)

(Unaudited)

Three Months Ended December 31, Three Months Ended March 31,

2025 2026 2025

(in millions of dollars, except percentages)

Performance and Essential Materials Segment

Loss from operations

$ (717) $ (211) $ (163)

Add:

Identified Items 495 17 7

Loss from operations excl. Identified Items

(222) (194) (156)

Add:

Depreciation and amortization 233 221 227

Other income, net 34 9 9

EBITDA excl. Identified Items

45 36 80

Less:

Identified Items 495 17 7

EBITDA

$ (450) $ 19 $ 73

Net external sales $ 1,632 $ 1,659 $ 1,850

Operating loss margin

(44)% (13)% (9)%

Operating loss margin excl. Identified Items

(14)% (12)% (8)%

EBITDA margin

(28)% 1% 4%

EBITDA margin excl. Identified Items

3% 2% 4%

xiii

WESTLAKE CORPORATION

SUPPLEMENTAL INFORMATION

PRODUCT SALES PRICE AND VOLUME VARIANCE BY OPERATING SEGMENTS

(Unaudited)

First Quarter 2026 vs. First Quarter 2025 First Quarter 2026 vs. Fourth Quarter 2025

Average

Sales Price Volume Average

Sales Price Volume

Housing and Infrastructure Products -2 % +2 % -5 % +15 %

Performance and Essential Materials -3 % -8 % +3 % -2 %

Company -3 % -4 % +1 % +4 %

WESTLAKE CORPORATION

SUPPLEMENTAL INFORMATION

PRODUCT SALES PRICE AND VOLUME VARIANCE BY OPERATING SEGMENTS - EXCLUDING PLANT CLOSURES AND ACQUISITION (1)

(Unaudited)

First Quarter 2026 vs. First Quarter 2025 First Quarter 2026 vs. Fourth Quarter 2025

Average

Sales Price Volume Average

Sales Price Volume

Housing and Infrastructure Products -2 % -2 % -5 % +10 %

Performance and Essential Materials -3 % — % +3 % +3 %

Company -3 % -1 % +1 % +6 %

______________________________

(1)Adjustments include:

a.Excludes sales in the comparative periods related to certain of the Company's North America Chlorovinyls production facilities, including (i) its polyvinyl chloride plant at the Aberdeen, Mississippi facility, (ii) its vinyl chloride monomer plant at the Lake Charles, Louisiana North facility, and (iii) one of its diaphragm chlor-alkali units at the Lake Charles, Louisiana South facility, and the Company's styrene production plant located at the Lake Charles, Louisiana facilities, each of which ceased operations in December 2025.

b.Excludes sales in the comparative periods related to a PVC resin production unit in China at the Company's 95% owned Huasu joint venture, which ceased operations in June 2025.

c.Excludes Q1 2026 sales related to ACI, which was acquired by the Company in January 2026.

xiv

EX-99.2

Filename: ex992_20260331wlkearning.htm · Sequence: 3

ex992_20260331wlkearning

1 Earnings Presentation 1Q 2026

2 First Quarter 2026 Highlights • Intra-quarter improvement in PEM’s average sales price with further realizations expected to benefit subsequent quarters as a result of a steepening of the global cost curve due to the Middle East conflict • On track to deliver 2026 EBITDA uplift of $600 million from our three-pillar profitability improvement plan (footprint optimization, cost savings and improved plant reliability) • PEM sales volume (excl. plant closures)(4) increased both YoY and QoQ for the first time since 2Q’24 driven by higher PVC resin production and sales volume • Strong Pipe and Fittings sales volume growth from sustained strength in infrastructure spending, including data centers’ needs for cooling water • Acquisition of ACI in January 2026 improves HIP’s exposure to the fast-growing high- voltage wire & cable market • Solid investment-grade rated balance sheet with $2.5 billion of cash and equivalents(3) (1) Excludes “Identified Items” consisting of a $67 million charge to settle certain litigation involving direct purchasers of PVC pipe and fittings and $18 million of charges related to previously announced facility shutdowns (2) Reconciliation of EBITDA excl. Identified Items to the applicable GAAP measure can be found on page 11 (3) Includes investments in available-for-sale securities (4) Certain of PEM's North America chlorovinyls production facilities ceased operations in December 2025, including (i) the polyvinyl chloride plant at the Aberdeen, Mississippi facility, (ii) the vinyl chloride monomer plant at the Lake Charles, Louisiana North facility and (iii) a diaphragm chlor-alkali unit at the Lake Charles, Louisiana South facility, as well as the styrene production plant located at the Lake Charles, Louisiana facility. The PVC resin production unit owned by the Huasu joint venture ceased operations in June 2025. In January 2026, HIP completed the acquisition of ACI. 1Q 2026 Financial Results $235M EBITDA(1,2) $2.7B Net Sales $2.5B Cash, Equivalents and Investments(3)

3 Westlake Corporation 1Q 2026 (1) Westlake 1Q 2026 vs. 4Q 2025 (3) Average Sales Price +0.5% Volume +5.8% Westlake 1Q 2026 vs. 1Q 2025 (3) Average Sales Price -2.5% Volume -0.6% (1) Excludes “Identified Items” consisting of: a $67 million charge to settle certain litigation involving direct purchasers of PVC pipe and fittings and $18 million of charges related to previously announced facility shutdowns in 1Q’26; $495 million of PEM shutdown charges and $16 million for HIP restructuring charges in 4Q’25; and $7 million of charges related to previously announced facility shutdowns in 1Q’25 (2) Reconciliations of Operating Income (Loss) excl. Identified Items, HIP EBITDA excl. Identified Items and PEM EBITDA excl. Identified Items to the applicable GAAP measure can be found on pages 11 and 12 (3) Excludes the impact of plant closures and the ACI acquisition. See note 4 on page 2. Our three-pillar profitability improvement plan drove ~$150 million of EBITDA uplift in 1Q’26 towards our FY’26 target of $600 million 1Q'26 4Q'25 QoQ% 1Q'25 YoY% $2,652 $2,533 5% $2,846 (7%) ($87) ($160) N.M. ($25) N.M. Housing and Infrastructure Products $186 $146 27% $203 (8%) Performance and Essential Materials $36 $45 (20%) $80 (55%) Corporate $13 $5 - $12 - $235 $196 20% $295 (20%) Operating Loss(1) Sales EBITDA(1,2) ($ in millions) Lower average sales price and higher natural gas costs drove a YoY decline in EBITDA Sequentially higher sales volume and average sales price driven by seasonally higher HIP demand and improved export demand for PEM

4 Housing and Infrastructure Products (“HIP”) Segment Performance(1) HIP Segment 1Q 2026 vs. 4Q 2025 (4) Average Sales Price -4.8% Volume +10.3% HIP Segment 1Q 2026 vs. 1Q 2025 (4) Average Sales Price -2.3% Volume -2.3% Slow start to the homebuilding season due to unusually cold weather across much of the United States (1) Excludes “Identified Items” consisting of a $67 million charge to settle certain litigation involving direct purchasers of PVC pipe and fittings and $1 million of charges related to previously announced facility shutdowns in 1Q’26; and $13 million accrued footprint optimization expenses and a $3 million loss on the sale of a compounding business in 4Q’25 (2) Reconciliations of HIP Operating Income excl. Identified Items and EBITDA excl. Identified Items to the applicable GAAP measure can be found on page 12 (3) HIP EBITDA margin is calculated by dividing HIP EBITDA by Total HIP Sales (4) Excludes the impact of the ACI acquisition. See note 4 on page 2. Continued strong YoY Pipe & Fittings sales volume growth from strong infrastructure spending growth, including increasing demand to supply cooling water to data centers 1Q'26 4Q'25 QoQ% 1Q'25 YoY% Housing Products Sales $788 $767 3% $838 (6%) Infrastructure Products Sales $205 $134 53% $158 30% Total HIP Sales $993 $901 10% $996 (0%) Operating Income(1) $124 $82 51% $148 (16%) EBITDA(1,2) $186 $146 27% $203 (8%) EBITDA Margin (1,3) 19% 16% - 20% - ($ in millions) With slower residential construction activity in North America and rising costs due to the Middle East conflict, 2026 revenue and EBITDA margin are now expected to be at the lower ends of the previously-communicated ranges of $4.4 – $4.6 billion of sales with a 19% – 21% EBITDA margin(3)

5 Housing and Infrastructure Products Update 2 Our 2026 outlook for exterior building products sales volume reflects the slow start to the homebuilding season and additional pressure on home affordability from increased building costs 3 New PVCO pipe plant under construction to support the strong growth and market adoption of this innovative product that reduces labor costs by streamlining the installation process 4 Strong presence in repair & remodel provides stability and steady growth driven by large number of homes in prime remodel age, healthy home equity levels, and significant backlog of projects 1 Longer-term housing fundamentals remain strong due to decade-plus of under-building, increasingly favorable demographics and popularity of remote work

6 PEM Segment 1Q 2026 vs. 4Q 2025 (4) Average Sales Price +3.5% Volume +3.2% PEM Segment 1Q 2026 vs. 1Q 2025 (4) Average Sales Price -2.6% Volume +0.4% Volume growth(4) driven by higher PVC resin production and sales volume, including stronger export market demand Sequentially higher average sales price as a result of olefins, polyethylene and caustic soda price increases (1) Excludes “Identified Items” consisting of: $17 million of charges related to previously announced facility shutdowns in 1Q’26; $495 million of charges related to previously announced facility shutdowns in 4Q’25; and $7 million of charges related to previously announced facility shutdowns in 1Q’25 (2) Reconciliations of PEM Operating Income (Loss) excl. Identified Items and PEM EBITDA excl. Identified Items to the applicable GAAP measure can be found on page 12 (3) PEM EBITDA margin is calculated by dividing PEM EBITDA excl. Identified Items by Total PEM Sales (4) Excludes the impact of plant closures. See note 4 on page 2. Performance and Essential Materials (“PEM”) Segment Performance(1) A 34% QoQ increase in natural gas prices, as a result of unusually cold weather early in 1Q’26, drove sequentially lower EBITDA Low cost position in North America with a high degree of production security to supply global demand 1Q'26 4Q'25 QoQ% 1Q'25 YoY% Performance Materials Sales $1,003 $930 8% $1,056 (5%) Essential Materials Sales $656 $702 (7%) $794 (17%) Total PEM Sales $1,659 $1,632 2% $1,850 (10%) Operating Loss(1) ($194) ($222) N.M. ($156) N.M. EBITDA(1,2) $36 $45 (20%) $80 (55%) EBITDA Margin (1,3) 2% 3% - 4% - ($ in millions)

7 Performance and Essential Materials Update 2 Following a spike early in 1Q’26, U.S. natural gas prices have declined sharply which could provide a tailwind to PEM’s margins for the remainder of 2026 3 Relatively stable North American demand as global macroeconomic conditions remain weak in Europe and Asia, but Westlake’s high degree of product integration and large offtake of PVC resin to the HIP segment provide less exposure to weaker economies outside North America 4 The significant majority of the targeted $600 million company-wide EBITDA uplift in 2026 from our three-pillar profitability improvement plan is expected to benefit the PEM segment 1 Energy and feedstock advantages in North America (~85% of our production capacity) and our high degree of vertical integration relative to the global industry positions us to benefit from the steepening global cost curve and serve our customers well

8 Financial Reconciliations

9 Consolidated Statements of Operations Housing and Infrastructure Products Sales $ 993 $ 996 $ 901 Performance and Essential Materials Sales 1,659 1,850 1,632 Net sales 2,652 2,846 2,533 Cost of sales Gross profit Selling, general and administrative expenses Amortization of intangibles Restructuring, transaction and integration-related costs Loss from operations Interest expense Other income, net Loss before income taxes Provision for (benefit from) income taxes Net loss Net income attributable to noncontrolling interests Net loss attributable to Westlake Corporation $ (169) $ (40) $ (544) Loss per common share attributable to Westlake Corporation: Basic $ (1.31) $ (0.31) $ (4.22) Diluted $ (1.31) $ (0.31) $ (4.22) 5 11 12 (533) 1 501 (671) (51) 59 2025 (In millions of dollars, except per share data) (663) (130) (33) (56) (39) (35) (190) (34) 38 37 (157) 18 7 (172) (32) 30 30 33 236 227 224 Three months ended March 31, Three months ended December 31, 112 232 2025 2,446 87 2,540 2,614 2026

10 Reconciliation of Net Loss Attributable to Westlake Corporation and Loss Per Diluted Share to Net Loss and Diluted Loss Per Share excl. Identified Items Net loss $ (157) $ (35) $ (533) Less: Net income attributable to noncontrolling interests Net loss attributable to Westlake Corporation (169) (40) (544) Add: Identified Items, after-tax Net loss attributable to Westlake Corporation excl. Identified Items $ (100) $ (33) $ (131) Diluted loss per common share attributable to Westlake Corporation $ (1.31) $ (0.31) $ (4.22) Add: Identified Items per share Diluted loss per common share attributable to Westlake Corporation excl. Identified Items $ (0.77) $ (0.26) $ (1.02) (In millions of dollars, except per share data) Three months ended March 31, Three months ended December 31, 2026 2025 2025 12 5 11 69 3.20 0.05 413 7 0.54

11 Reconciliation of EBITDA excl. Identified Items to EBITDA, Net Loss, Loss from Operations and Net Cash Provided by (Used for) Operating Activities Net cash provided by (used for) operating activities $ (94) $ (77) $ 225 Changes in operating assets and liabilities and other Deferred income taxes Net loss Less: Other income, net Interest expense Benefit from (provision for) income taxes Loss from operations Add: Depreciation and amortization Other income, net EBITDA $ 150 $ 288 $ (315) Add: Identified Items EBITDA excl. Identified Items $ 235 $ 295 $ 196 Loss from operations margin (6%) (1%) (26%) EBITDA excl. Identified Items margin 9% 10% 8% 85 7 511 Three months ended March 31, 20252026 2025 Three months ended December 31, (In millions of dollars) (975)(29) 41 217 (34) 1 (533)(157) (35) (51)(56) (39) 59 38 37 (671) (172) (32) 130 33 (1) 297 284 283 59 38 37

12 Reconciliation of HIP EBITDA excl. Identified Items, PEM EBITDA excl. Identified Items and Corporate EBITDA to Operating Income (Loss) Three months ended March 31, Three months ended December 31, 2026 2025 2025 Housing and Infrastructure Products EBITDA excl. Identified Items $ 186 $ 203 $ 146 Less: Identified Items 68 - 16 Depreciation and Amortization 60 53 61 Other income, net 2 2 3 Housing and Infrastructure Products Operating Income 56 148 66 Performance and Essential Materials EBITDA excl. Identified Items 36 80 45 Less: Identified Items 17 7 495 Depreciation and Amortization 221 227 233 Other income, net 9 9 34 Performance and Essential Materials Operating Loss (211) (163) (717) Corporate EBITDA 13 12 5 Less: Depreciation and Amortization 3 3 3 Other income, net 27 26 22 Corporate Operating Loss (17) (17) (20) Housing and Infrastructure Products Operating Income 56 148 66 Performance and Essential Materials Operating Loss (211) (163) (717) Corporate Operating Loss (17) (17) (20) Total Operating Loss (172)$ (32)$ (671)$ (In millions of dollars)

13 Reconciliation of Free Cash Flow to Net Cash Provided by (Used for) Operating Activities Net cash provided by (used for) operating activities $ (94) $ (77) $ 225 Less: Additions to property, plant and equipment Free Cash Flow $ (303) $ (325) $ (16) 209 248 241 (In millions of dollars) Three months ended March 31, Three months ended December 31, 2026 2025 2025

14 Safe Harbor Language This presentation contains certain forward-looking statements including statements regarding our cost savings objectives and our ability to maintain synergies, pricing and demand for our products and across the industrial and manufacturing sectors, global macroeconomic conditions, anticipated sales volumes, industry outlook for both of our segments, our ability to execute our integrated strategy, projected benefits from the shutdown of certain of our PEM facilities, our cost control and efficiency efforts (such as achieving a $600 million uplift to EBITDA in 2026 from our profitability improvement plan), our future operating results, including revenues and EBITDA, our expectations regarding previously communicated ranges of our HIP segment’s revenue and EBITDA margin for 2026, our competitive position, the effects of changing demographics in the markets that we serve, anticipated residential construction, repair and remodel activities and infrastructure spending growth, long-term housing market fundamentals, changes in sales mix of our products, expectations regarding homebuilder confidence, our relationships with our customers and their adoption of our products, the benefits of our acquisition of ACI, and the effects of the conflict in the Middle East, including the benefits of our energy and feedstock cost advantages in the North American chemicals market. Actual results may differ materially depending on factors, including, but not limited to, the following: general economic and business conditions; the cyclical nature of the chemical and building products industries; the availability, cost and volatility of raw materials and energy; uncertainties associated with the United States, European and worldwide economies, including those due to political tensions and conflict in the Middle East, Russia, Ukraine and elsewhere; uncertainties associated with climate change; the potential impact on the demand for ethylene, polyethylene and polyvinyl chloride due to initiatives such as recycling and customers seeking alternatives to polymers; current and potential governmental regulatory actions in the United States and other countries; industry production capacity and operating rates; the supply/demand balance for our products; competitive products and pricing pressures; instability in the credit and financial markets; access to capital markets; terrorist acts; operating interruptions; changes in laws or regulations, including trade policies; disruptions in global trade; the effects of government shutdowns; technological developments; information systems failures and cyber attacks; foreign currency exchange risks; our ability to implement our business strategies; creditworthiness of our customers; the effect and results of litigation and settlements of litigation; and other factors described in our reports filed with the Securities and Exchange Commission. Many of these factors are beyond our ability to control or predict. Any of these factors, or a combination of these factors, could materially affect our future results of operations and the ultimate accuracy of the forward-looking statements. These forward-looking statements are not guarantees of our future performance, and our actual results and future developments may differ materially from those projected in the forward-looking statements. Management cautions against putting undue reliance on forward-looking statements. Every forward-looking statement speaks only as of the date of the particular statement, and we undertake no obligation to publicly update or revise any forward-looking statements except as required by applicable law. Investor Relations Contacts Steve Bender Executive Vice President & Chief Financial Officer Jeff Holy Vice President & Chief Accounting Officer Westlake Corporation 2801 Post Oak Boulevard, Suite 600, Houston, Texas 77056 | 713-960-9111

GRAPHIC

Filename: ex992_20260331wlkearning001.jpg · Sequence: 8

Binary file (90841 bytes)

Download ex992_20260331wlkearning001.jpg

GRAPHIC

Filename: ex992_20260331wlkearning002.jpg · Sequence: 9

Binary file (183451 bytes)

Download ex992_20260331wlkearning002.jpg

GRAPHIC

Filename: ex992_20260331wlkearning003.jpg · Sequence: 10

Binary file (118241 bytes)

Download ex992_20260331wlkearning003.jpg

GRAPHIC

Filename: ex992_20260331wlkearning004.jpg · Sequence: 11

Binary file (142161 bytes)

Download ex992_20260331wlkearning004.jpg

GRAPHIC

Filename: ex992_20260331wlkearning005.jpg · Sequence: 12

Binary file (137583 bytes)

Download ex992_20260331wlkearning005.jpg

GRAPHIC

Filename: ex992_20260331wlkearning006.jpg · Sequence: 13

Binary file (140490 bytes)

Download ex992_20260331wlkearning006.jpg

GRAPHIC

Filename: ex992_20260331wlkearning007.jpg · Sequence: 14

Binary file (161740 bytes)

Download ex992_20260331wlkearning007.jpg

GRAPHIC

Filename: ex992_20260331wlkearning008.jpg · Sequence: 15

Binary file (187919 bytes)

Download ex992_20260331wlkearning008.jpg

GRAPHIC

Filename: ex992_20260331wlkearning009.jpg · Sequence: 16

Binary file (100766 bytes)

Download ex992_20260331wlkearning009.jpg

GRAPHIC

Filename: ex992_20260331wlkearning010.jpg · Sequence: 17

Binary file (99676 bytes)

Download ex992_20260331wlkearning010.jpg

GRAPHIC

Filename: ex992_20260331wlkearning011.jpg · Sequence: 18

Binary file (100993 bytes)

Download ex992_20260331wlkearning011.jpg

GRAPHIC

Filename: ex992_20260331wlkearning012.jpg · Sequence: 19

Binary file (101028 bytes)

Download ex992_20260331wlkearning012.jpg

GRAPHIC

Filename: ex992_20260331wlkearning013.jpg · Sequence: 20

Binary file (68797 bytes)

Download ex992_20260331wlkearning013.jpg

GRAPHIC

Filename: ex992_20260331wlkearning014.jpg · Sequence: 21

Binary file (246458 bytes)

Download ex992_20260331wlkearning014.jpg

GRAPHIC

Filename: ex992_20260331wlkearning015.jpg · Sequence: 22

Binary file (52072 bytes)

Download ex992_20260331wlkearning015.jpg

XML — IDEA: XBRL DOCUMENT

XML

Filename: R1.htm · Sequence: 24

v3.26.1

Cover Page

May 05, 2026

Document Information [Line Items]

Document Type

8-K

Document Period End Date

May 05, 2026

Entity Registrant Name

Westlake Corporation

Entity Incorporation, State or Country Code

Entity File Number

001-32260

Entity Tax Identification Number

76-0346924

Entity Address, Address Line One

2801 Post Oak Boulevard,

Entity Address, Address Line Two

Suite 600

Entity Address, City or Town

Houston,

Entity Address, State or Province

Entity Address, Postal Zip Code

77056

City Area Code

713

Local Phone Number

960-9111

Written Communications

false

Soliciting Material

false

Pre-commencement Tender Offer

false

Pre-commencement Issuer Tender Offer

false

Entity Emerging Growth Company

false

Amendment Flag

false

Entity Central Index Key

0001262823

Common Stock [Member]

Document Information [Line Items]

Title of 12(b) Security

Common Stock, $0.01 par value

Trading Symbol

WLK

Security Exchange Name

NYSE

One Point Six Two Five Percentage Senior Notes Due Twenty Twenty Nine [Member] [Domain]

Document Information [Line Items]

Title of 12(b) Security

1.625% Senior Notes due 2029

Trading Symbol

WLK29

Security Exchange Name

NYSE

- Definition

Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.

+ References

No definition available.

+ Details

Name:

dei_AmendmentFlag

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Area code of city

+ References

No definition available.

+ Details

Name:

dei_CityAreaCode

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:

dei_DocumentInformationLineItems

Namespace Prefix:

dei_

Data Type:

xbrli:stringItemType

Balance Type:

Period Type:

duration

- Definition

For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.

+ References

No definition available.

+ Details

Name:

dei_DocumentPeriodEndDate

Namespace Prefix:

dei_

Data Type:

xbrli:dateItemType

Balance Type:

Period Type:

duration

- Definition

The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

+ References

No definition available.

+ Details

Name:

dei_DocumentType

Namespace Prefix:

dei_

Data Type:

dei:submissionTypeItemType

Balance Type:

Period Type:

duration

- Definition

Address Line 1 such as Attn, Building Name, Street Name

+ References

No definition available.

+ Details

Name:

dei_EntityAddressAddressLine1

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Address Line 2 such as Street or Suite number

+ References

No definition available.

+ Details

Name:

dei_EntityAddressAddressLine2

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Name of the City or Town

+ References

No definition available.

+ Details

Name:

dei_EntityAddressCityOrTown

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Code for the postal or zip code

+ References

No definition available.

+ Details

Name:

dei_EntityAddressPostalZipCode

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Name of the state or province.

+ References

No definition available.

+ Details

Name:

dei_EntityAddressStateOrProvince

Namespace Prefix:

dei_

Data Type:

dei:stateOrProvinceItemType

Balance Type:

Period Type:

duration

- Definition

A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityCentralIndexKey

Namespace Prefix:

dei_

Data Type:

dei:centralIndexKeyItemType

Balance Type:

Period Type:

duration

- Definition

Indicate if registrant meets the emerging growth company criteria.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityEmergingGrowthCompany

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

+ References

No definition available.

+ Details

Name:

dei_EntityFileNumber

Namespace Prefix:

dei_

Data Type:

dei:fileNumberItemType

Balance Type:

Period Type:

duration

- Definition

Two-character EDGAR code representing the state or country of incorporation.

+ References

No definition available.

+ Details

Name:

dei_EntityIncorporationStateCountryCode

Namespace Prefix:

dei_

Data Type:

dei:edgarStateCountryItemType

Balance Type:

Period Type:

duration

- Definition

The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityRegistrantName

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityTaxIdentificationNumber

Namespace Prefix:

dei_

Data Type:

dei:employerIdItemType

Balance Type:

Period Type:

duration

- Definition

Local phone number for entity.

+ References

No definition available.

+ Details

Name:

dei_LocalPhoneNumber

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 13e

-Subsection 4c

+ Details

Name:

dei_PreCommencementIssuerTenderOffer

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 14d

-Subsection 2b

+ Details

Name:

dei_PreCommencementTenderOffer

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Title of a 12(b) registered security.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b

+ Details

Name:

dei_Security12bTitle

Namespace Prefix:

dei_

Data Type:

dei:securityTitleItemType

Balance Type:

Period Type:

duration

- Definition

Name of the Exchange on which a security is registered.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection d1-1

+ Details

Name:

dei_SecurityExchangeName

Namespace Prefix:

dei_

Data Type:

dei:edgarExchangeCodeItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as soliciting material pursuant to Rule 14a-12 under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 14a

-Subsection 12

+ Details

Name:

dei_SolicitingMaterial

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Trading symbol of an instrument as listed on an exchange.

+ References

No definition available.

+ Details

Name:

dei_TradingSymbol

Namespace Prefix:

dei_

Data Type:

dei:tradingSymbolItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as written communications pursuant to Rule 425 under the Securities Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Securities Act

-Number 230

-Section 425

+ Details

Name:

dei_WrittenCommunications

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Details

Name:

us-gaap_StatementClassOfStockAxis=us-gaap_CommonStockMember

Namespace Prefix:

Data Type:

Balance Type:

Period Type:

- Details

Name:

us-gaap_StatementClassOfStockAxis=wlk_OnePointSixTwoFivePercentageSeniorNotesDueTwentyTwentyNineMemberDomain

Namespace Prefix:

Data Type:

Balance Type:

Period Type: