Owens Corning Focused on Shareholder Value

Owens Corning

Focused on Shareholder Value

Q2 2017This presentation shared at the following event(s):

5/19/17 OC Roadshow Hosted by RBC – Boston Brian Chambers, President, Roofing & Asphalt

2

Forward-Looking Statements and Non-GAAP Measures

This presentation and the associated remarks and comments contain forward-looking statements. We caution you against relying on these statements as they involve risks and uncertainties that are difficult to predict and the Company’s actual results may differ materially from those projected in these statements. Such risks and uncertainties include, without limitation: relationships with key customers and demand for our products; macroeconomic factors like levels of construction activity, global industrial production, industry, economic and political conditions, including new legislation, policies or other governmental actions by the new U.S. presidential administration and Congress; competitive and pricing factors; currency, commodity and interest rate fluctuations; our level of indebtedness and the availability and cost of credit; weather conditions; energy and raw material availability, price volatility and cost issues; ability to protect our intellectual property and information technology systems; labor disputes, legal and regulatory proceedings; our ability to utilize our net operating loss carry-forwards; issues related to acquisitions, divestitures and joint ventures; and, factors detailed from time to time in the Company’s SEC filings.

For purposes of this presentation, any discussion referring to “year to date” or last twelve months (“LTM”) refers to the period ended on the last calendar day of the quarter preceding the date of the investor event referred to on the first page of this document. Otherwise the information in this presentation speaks as of the date of the investor event, and is subject to change. The Company does not undertake any obligation to update or revise forward-looking statements beyond what is required under applicable securities laws. Any distribution of this presentation after the date of the investor event is not intended and should not be construed as updating or confirming such information.

This presentation contains references to certain "non-GAAP financial measures" as defined by the SEC, including EBIT, adjusted EBIT, adjusted earnings, adjusted EPS, adjusted pre-tax earnings, free cash flow, free cash flow conversion of adjusted earnings, free cash flow yield and return on capital. Management uses non-GAAP measures for various purposes, including reporting results of operations to the Board of Directors, analysis of performance and related employee compensation measures. Although management believes these measures, and exclusions from GAAP therein, provide a useful representation of performance or liquidity, non-GAAP measures should not be considered in isolation or as a substitute for the corresponding GAAP measures. A reconciliation of these non-GAAP financial measures to their most directly comparable financial measures calculated and presented in accordance with GAAP can be found in the text and tables of our most recent earnings Press Release filed with the SEC on Form 8-K and in Appendix B. When the company provides forward-looking expectations for non-GAAP measures, the most comparable GAAP measures and a reconciliation between the non-GAAP expectations and the corresponding GAAP measures are generally not available without unreasonable effort due to the variability,complexity and limited visibility of the adjusting items that would be excluded from the non-GAAP measures in future periods. The variability in timing and amount of adjusting items could have significant and unpredictable effects on future GAAP results.

Adjusted EBIT, adjusted earnings, adjusted EPS, adjusted pre-tax earnings and return on capital exclude certain items that management does not allocate to its segment results because it believes they are not representative of the Company’s ongoing operations. Free cash flow is a non-GAAP liquidity measure used by investors, financial analysts and management to help evaluate the company's ability to generate cash to pursue opportunities that enhance shareholder value. Free cash flow is not a measure of residual cash flow available for discretionary expenditures due to the company’s mandatory debt service requirements. As a conversion ratio, free cash flow is compared to adjusted earnings. Free cash flow yield is a non-GAAP liquidity measure that management believes is useful to investors to compare a company’s ability to generate free cash flow to its market valuation. Free cash flow yield is not a measure of cash flow which accrues directly to the benefit of common stock share owners.

The Company

Investment Thesis

Three Strong Businesses

Additional Financial Information

Agenda

4

Owens Corning at a Glance

1938

Founded

Over 79

Years Ago

2016

Sales

Countries

Around

the World

Employees

Worldwide

Consecutive

Years on the

Fortune 500®

Three

Strong

Businesses

$5.7 BILLION

Source: Owens Corning SEC filings and Fortune Magazine

16k 26 62

5

Balanced End Market Exposure

Source: Owens Corning management estimates; estimated error margin below 5%. Consolidated figures eliminate intercompany sales between reportable segments.

15%

38%21%

26%

2016 OC REVENUE BY END MARKET

U.S. & Canada Residential New Construction

U.S. & Canada Repair and Remodeling

U.S. & Canada Commercial and Industrial

International

8%

79%

12%

1%

Roofing

36%

23%

25%

16%

Insulation3%

11%

26%60%

Composites

The Company

Investment Thesis



Agenda

7

OC Investment Thesis

Focused on Shareholder Value

Market

Leading

Businesses

2

Improved

Portfolio,

Earnings &

Cash Flow

3

Attractive

Macro

Drivers

1

Favorable

global trends

Positive

market outlook

Leadership

positions in

attractive industries

Valuable brands

Low-cost assets

Disciplined

capital allocation

Access to growth

opportunities

Improving capital

intensity

8

Portfolio Improvement Has Lifted Margin Profile

Implemented sustainable cost improvements

Drove substantial Components growth

Acquired synthetic underlayment leader InterWrap

Served market needs with premium products

Acquired and expanded mineral fiber assets

Grew business outside North America

Returned engineered & regional business to record levels

Lowered breakeven point

Repositioned low-cost network

Reduced capital intensity

Accelerated pace of product innovation

Demonstrated industry supply tension

Adjusted

EBIT

Margin:

Insulation

Roofing

Composites

13%2007 - 10

2011 - 16

2016

9%7%

Please refer to Table 1 of Appendix B for reconciliation to Owens Corning SEC filings.

9

Return on capital is defined as net operating profit after tax divided by total capital. Please refer to Table 2 in Appendix B for reconciliation to Owens Corning SEC filings. Total capital is the average of beginning and ending balances of property, plant and equipment, accounts receivable, inventories, post-emergence goodwill and intangibles, less accounts payable.

Portfolio Improvement Has Boosted

Return on Capital

4%

6%

8%

10%

12%

2012 2013 2014 2015 2016

Return on Capital

10

18%

Significantly Improved Free Cash Flow

Please refer to Table 3 in Appendix B for reconciliation to Owens Corning SEC filings.

-100

0

100

200

300

400

500

600

2012 2013 2014 2015 2016

Mill

ion

s o

f $

2012-2014 management

actions to improve portfolio

constrained cash flow

performance

Free cash flow conversion

of adjusted earnings expected

to be about 100% on average

over 2015 to 2018

Free Cash Flow

Free Cash Flow

Conversion:126%

11

Source: Management estimates, based on 2016 data from CapitalIQ. Management believes this disclosure is useful to investors to compare a company’s ability to generate free cash

flow to its market valuation. Free cash flow yield is not a measure of cash flow which accrues directly to the benefit of common stock share owners. Calculation may differ from methods

used by peers in similar disclosures. Peer group represents building materials companies most covered by sell-side analysts who publish on Owens Corning. For detail on the formula

and GAAP reconciliation of the Owens Corning measurement, please refer to Table 4 in Appendix B.

Superior Free Cash Flow Yield Within Sector

Peer Average

0%

1%

2%

3%

4%

5%

6%

7%

8%

9%

10%

12

Disciplined Capital Allocation Strategy

Drive shareholder returns by enabling organic and inorganic growth and supporting the balance sheet

o Maintain investment grade

Capital allocation strategy

o Investing in attractive organic growth

o Pursuing value-creating acquisitions

o Returning cash to shareholders

Strong cash flow outlook supports dividend growth, share repurchase and acquisitions

Benefit from $1.8B U.S. Federal N.O.L. with estimated present value of approximately $5 per share

Source: U.S. Federal et operating loss (“N.O.L.”) as of 12/31/2016, as reported in Owens Corning SEC filings.

The Company

Investment Thesis



Agenda

14

2016

(Millions $)Insulation Roofing Composites Corporate Total

Net sales 1,748 2,194 1,952 (217) 5,677

EBIT / Adj EBIT 126 486 264 (130) 746

EBIT / Adj EBIT as % of

sales7% 22% 14% 13%

Portfolio Financial Profile

Source: Owens Corning SEC filings. For the Corporate column, Net sales reflects intercompany eliminations and EBIT reflects General corporate expense and other as disclosed in our

SEC filings. The Total column reflects total company Adjusted EBIT, which is reconciled to Owens Corning SEC filings in Table 5 of Appendix B.

15

Margin >= 10% 0%<= Margin < 10% Margin < 0%

'97 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07 '08 '09 '10 '11 '12 '13 '14 '15 '16

Insulation

Roofing

Composites

Strong Portfolio

Last 20 years of performance. Source: Owens Corning’s SEC filings since 2006. For comparability purposes, prior years have been provided based on Owens Corning’s SEC filings,

internal management reports, and management estimates.

16

Insulation Business

Track record of proven performance

Strong brand and broad product portfolio

Investment opportunities for global

expansion

Confidence in return to historical

profitability

Source: Owens Corning SEC filings; segment reporting comparability may differ over time

* In millions

Sales* EBIT as % of sales

Progress supports confidence in return to historical profitability

INSULATION

-5%

0%

5%

10%

15%

$0

$500

$1,000

$1,500

$2,000

2013 2014 2015 2016 LTM

17

-10%

0%

10%

20%

30%

'85 '90 '95 '00 '05 '10 '15

EBIT Margin Avg EBIT Margin '85-'08 (15%)

Return to Historical Profitability Levels

Historically Delivered 15% EBIT Margins at 1.5 Million Housing Starts; Expect to Average 50% Operating Leverage through the Housing Recovery

Source: Owens Corning management estimates and SEC filings of Owens Corning and predecessor company. Segment reporting comparability may differ over time.

‘16

INSULATION

18

( 0.5)

( 0.3) ( 0.2)

4.6 4.1

3.8 3.6

2005 TotalCapacity

Retired 2016 TotalCapacity

Mothballed OperatingPlants

Capacity

Cold Lines OperatingLines Capacity

Capacity

Utilization: 100% 73% 85% 90%

2005

B L

bs

U.S. & Canada Fiberglass Industry

Light Density Network Capacity and Demand

Light density fiberglass demand and capacity based on assets producing batts, rolls, flexible duct media, metal building insulation, duct wrap and appliance insulation; excludes loosefill products. Capacity utilization reported in 5% increments. Source: Owens Corning management estimates as of January 2017 and various industry sources and publications (including North America Insulation Manufacturers Association); all competitive information legally obtained from appropriate 3rd party sources.

80% 85% 90%

2016

2.1 MM

U.S. Housing Starts

1.2 MM

U.S. Housing Starts

INSULATION

19

Market Pricing Still Significantly Below

Historical Levels

OC U.S. New Construction Price Index

60%

70%

80%

90%

100%

2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016

Source: Owens Corning management estimates as of January 2017. Owens Corning nominal price index based on average price of fiberglass batts to U.S. contractors.

INSULATION

20

Residential Fiberglass Below Historical

Levels; Non-Residential at Record Levels

Residential fiberglass building insulation includes batts & rolls and loosefill sold to insulation contractors and distributors, home centers, and manufactured housing producers in the U.S. and Canada. Engineered insulation and other regions includes pipe and flexible duct media insulation, foam, mineral fiber, and all building material products sold to Latin America and Asia. Source: Owens Corning management estimates. Comparability may differ over time. Margin of error on intra-segment EBIT estimated to be below $15MM.

-200

-100

0

100

200

300

400

2006(Peak)

2009(Trough)

2015

MM

$

EBITMM$ & Margins

U.S. & Canada Residential Fiberglass Building Insulation

Engineered Insulation & Other Regions

26%

17%

-23%

4% 2%

14%

INSULATION

21

Signed agreement to acquire global brand leader of cellular glass

insulation and accessory products for approximately $560MM in cash,

on a cash-free and debt-free basis, subject to regulatory approvals

Consistent with Insulation business strategy of geographic and product

technology extension

Value contributors:

o Broadens range of attractive industrial & commercial applications

o Adds strong and stable margins through the cycle

o Significantly strengthens our global Insulation platform

o Leverages OC core glass technology strength

Business delivered revenue of over $240MM in 2016 and adjusted

EBITDA margins in a 25%-27% range over last 4 years

Expect acquisition to be accretive to 2017 EPS, excluding transaction

and integration costs

Anticipate a run rate of $20MM of operational and commercial synergies

by mid-2019

Sources: Owens Corning SEC filings; management estimates and press release issued May 15, 2017

Pittsburgh Corning Acquisition

Strengthens Position of Insulation Business

22

Roofing Business

Strong market position and leading brands

Performance track record through varied

market conditions

Confidence in sustaining average operating

margins of mid-teens or better

* In millions


Strong market position sustaining high operating margins

Source: Owens Corning SEC filings; segment reporting comparability may differ over time ROOFING

0%

5%

10%

15%

20%

25%

$0

$500

$1,000

$1,500

$2,000

$2,500

2013 2014 2015 2016 LTM

23

U.S. Asphalt Shingle Re-Roof Demand Drivers

Replacement age Average replacement age increased

driven by technological advances

Major storms & other weather events Weather events drive demand and create

early replacement of roofs

Weather-related demand estimated based on

NOAA data and insurance claims information

Economic factors Existing home sales, consumer income, and

borrowing capacity affect consumer decisions

on timing of re-roof

IMP

AC

T

LOW

HIGH

ROOFING

24

New Construction and Replacement Markets

Growing over Last Three Years

Source: Asphalt Roofing Manufacturers Association - Summary of Asphalt Roofing Industry Shipments. Management estimates based on data provided by National Oceanic and Atmospheric Administration (NOAA), National Association of Realtors, EIA, Moody’s Analytics, Oxford Economics reports, U.S. Bureau of Labor Statistics and U.S. Bureau of Economic Analysis.

MM Sq.

Total 136 143 145 154 161 173 155 129 135 120 108 122 118 111 107 112 133

U.S. Asphalt Shingle Market

30 31 32 34 37 39 3526

17 11 11 11 14 17 18 19 20

71 7581

86 8795

7775

7371 63 61 59 58 60 65 68

3234

3027

2821

35

25

2321 28 31 34 30 23

2430

33 2

78

18

8

322

17

6

1911

66

4

'00 '01 '02 '03 '04 '05 '06 '07 '08 '09 '10 '11 '12 '13 '14 '15 '16

New Construction Age Related/Economic Other Weather Events Major Storms

15

ROOFING

25

Track Record of Strong Financial Performance

Delivered average EBIT

margins of 18% since

2010 (ranging from 13%

to 22%)

Strong market position;

confidence in sustaining

average EBIT margins

of mid-teens or better

0

5

10

15

20

25

2010 2011 2012 2013 2014 2015 2016

%

Roofing EBIT Margin

Average 18%

Source: Owens Corning SEC filings; segment reporting comparability may differ over time ROOFING

26

Acquired and integrated leading manufacturer of synthetic

roofing underlayment and packaging materials for $452MM

on April 21st, 2016

Value contributors:

o Established track record of double-digit revenue growth

o Benefit from conversion of organic to synthetic underlayments

o OC channel strength and InterWrap strong products, brands

and technology

o Commercial and operational synergies

o Access to new markets and construction applications

Contributed $40MM of adjusted EBIT over last 8 months of

2016

Continue to anticipate achieving a run rate of $20MM or more of

commercial and operational synergies by end of 2017

Sources: Owens Corning SEC filings; management estimates and press release issued February 24, 2016

Successful InterWrap Acquisition

Strengthens Position of Roofing Components Business

27

Composites Business

A leader in a stable industry with strong growth

prospects

Improving economic conditions and higher

utilization rates

Transformed business delivering double-digit

EBIT margins & ROC

Strategy to deliver profitable, capital efficient

growthSource: Owens Corning SEC filings. Segment ROC differs from total company ROC. Please refer to Table 2 of Appendix B for explanation.

* In millions


Market-leading business with improving economic conditions and higher utilization rates

COMPOSITES

0%

5%

10%

15%

20%

$0

$500

$1,000

$1,500

$2,000

2013 2014 2015 2016 LTM

28

Glass Fiber

A $7.5 Billion Global Market With Favorable Exposure

Glass fiber market defined as glass fiber reinforcements and direct conversion products as consumed, excluding yarns. Source: Fiber Economics Bureau, GlassFibreEurope (APFE), Global Trade Information Services, Inc. and Owens Corning management estimates as of January 2017.

Markets

Size

Power & EnergyConsumerBuilding &

Construction

Transportation Industrial

COMPOSITES

29

Positioned to Compete Anywhere in the World

% Market Revenue = market revenue in region as % of 2016 global market size; % OC Revenue = OC revenue in region as % of OC Composites global 2016 sales; Glass reinforcements market defined as glass fiber reinforcements and direct conversion products as consumed, excluding yarns. Sources: Fiber Economics Bureau, GlassFibreEurope (APFE), Global Trade Information Services, Inc. and Owens Corning management estimates of 2016 global market.

33%

47%

% MarketRevenue

% OCRevenue

Americas

#1 Position

26%

11%

% MarketRevenue

% OCRevenue

China

Emerging PositionWorld headquarters

Composites facilities

#1 Position

23%28%

% MarketRevenue

% OCRevenue

Europe

#1 Position

18%14%

% MarketRevenue

% OCRevenue

Rest of World

COMPOSITES

30

0.5

1.8

0.8

1.7

0.9

0.8

2005-09 2010-16 2017E-19E50%

60%

70%

80%

90%

100%'05 '06 '07 '08 '09 '10 '11 '12 '13 '14 '15 '16 '17E '18E '19E

Expect Continued Supply Tension

Change in global

demand (MM T)

Change in global

capacity (MM T)

Estim

ate

d C

ap

acity U

tiliz

ation

China Emergence

Capacity Overbuild

Tightening Capacity

Price Inflection

Supply Tension

Improved Returns

90% Threshold

COMPOSITES

Glass fiber market demand excludes E-glass yarns. Sources: Fiber Economics Bureau, GlassFibreEurope (APFE), Global Trade Information Services, Inc. and Owens Corning management estimates as of May 2017 (high probability capacity additions only). Estimated demand calculated as 2016 demand grown at 1.6x growth rate of global IP per April 2017 Oxford Economics.

The Company

Investment Thesis



Agenda

32

Improved safety performance with recordable incident rate

down 11% year over year

Record first-quarter adjusted EBIT of $171MM

Roofing: $125MM EBIT; 20% EBIT margins

Composites: record first-quarter EBIT of $71MM

Insulation: return to revenue growth; $5MM EBIT

Repurchased 1.0MM shares in Q1

Anticipate continued growth in U.S. housing starts and

moderate global industrial production growth in 2017

Appendix A

Q1 2017 Highlights and Outlook

Source: Owens Corning SEC filings; Please refer to the tables in Appendix B for reconciliation of adjusted EBIT, free cash flow and free cash flow conversion to Owens Corning SEC filings.

33

($ in millions, except per share data)Q1

2017

Q1

2016

Net sales $1,478 $1,231

Net earnings attributable to Owens Corning $101 $57

Diluted earnings per share attributable to Owens Corning common stockholders

$0.89 $0.49

Earnings before interest and taxes (EBIT) $170 $116

Adjusted EBIT $171 $118

Adjusted Earnings $97 $62

Adjusted EPS (diluted) $0.85 $0.53

Adjusted EBIT as a % of sales 12% 10%

Depreciation and amortization $84 $76

Net cash flow provided by operating activities $7 $63

Free cash flow ($60) ($35)

Total debt (excluding rate swap), net of cash $2,151 $1,887

Appendix A

Key Financial Data - Corporate

Source: Owens Corning SEC filings; Please refer to the tables in Appendix B for reconciliation of EBIT, adjusted EBIT, adjusted earnings, adjusted EPS and free cash flow to Owens Corning SEC filings.

34

Insulation Roofing Composites

($ in millions) Q1 2017 Q1 2016 Q1 2017 Q1 2016 Q1 2017 Q1 2016

Net sales $399 $385 $627 $429 $511 $473

EBIT $5 $13 $125 $73 $71 $64

EBIT as % of sales 1% 3% 20% 17% 14% 14%

D&A $26 $25 $12 $10 $36 $34

Appendix A

Key Financial Data - Business

Source: Owens Corning SEC filings; reportable segment totals are shown in SEC filings before intercompany eliminations

35

Macro Environment

Environment consistent with consensus U.S. housing starts

Expect moderate global industrial production growth

Primary Guidance

Conversion of adjusted earnings into free cash

flow around 100%

Insulation: $100MM of revenue growth;

EBIT of $160MM or more

Composites: EBIT growth of about $25MM

Roofing: growth in new construction and age-

related markets more than offset by decline of

storm demand; benefit from full year of InterWrap

Corporate expenses in $120-$130MM range

Interest expense about $110MM

Capital expenditures about $375MM

Depreciation & amortization about $345MM

Cash tax rate of 10-12% and book tax rate of

32-34% on adjusted pre-tax earnings

Source: Owens Corning management estimates

Other Guidance Items

Appendix A

2017 Corporate Environment and Guidance

36

Appendix B

Non-GAAP Reconciliations – Table 1

37

Appendix B


38

Appendix B


39

Appendix B


40

Appendix B


41

Appendix B


Documents

Owens Corning Focused on Shareholder Value