Second Amendment to the Exchange Agreement, dated as of December 7, 2023, by and among Core & Main, Inc., Core & Main Holdings, LP, CD&R Waterworks Holdings, LLC and Core & Main Management Feeder, LLC

    “Initial True-up Amount” means a number of shares of Class A Common Stock that IPOco may require to be paid to or withheld from a Holder by IPOco in connection with a Liquidation Adjustment upon the submission by a Holder of a contingent Election of Exchange pursuant to Section 2.1(c) of this Agreement, with such amount to be determined by IPOco in IPOco’s sole discretion as it determines in good faith is required to properly reflect the principles set forth in Section 2.1(h) of this Agreement.

“Liquidation Adjustment Price” means the greater of (i) the last reported sales price of a share of the Class A Common Stock, as reported by Bloomberg, L.P., or its successor (or other mutually acceptable electronic or print publication) immediately prior to the relevant Exchange Date, (ii) the average of the daily volume-weighted average price (“VWAP”) of a share of Class A Common Stock for the four-week period immediately prior to the relevant Exchange Date in connection with a Voluntary Exchange and (iii) as applied with respect to an Excess Amount in connection with Section 2.1(h), such price of a share of Class A Common Stock that, in connection with an Exchange, would not result in the number of shares of Class A Common Stock to be issued to exceed the number of authorized and unissued shares of Class A Common Stock under the IPOco Charter, when taken together with (x) the outstanding shares of Class A Common

Stock, (y) the shares of Class A Common Stock issuable upon Exchange of outstanding shares of Paired Interests (disregarding shares of Class A Common Stock issuable under Section 2.1(h)), and (z) the shares of Class A Common Stock issuable under the Core & Main, Inc. 2021 Omnibus Equity Incentive Plan or any other IPOco stock incentive plan; provided that in calculating such average, (a) the VWAP shall be determined by calculating the arithmetic average of the per share daily volume-weighted average price of a share of Class A Common Stock on the New York Stock Exchange or such other principal U.S. securities exchange or automated or electronic quotation system on which Class A Common Stock trades, as reported by Bloomberg, L.P., or its successor (or other mutually acceptable electronic or print publication) for each of the full Trading Days in the four-week period immediately prior to the Exchange Date and ending on and including the last full Trading Day immediately prior to the Exchange Date, subject to appropriate and equitable adjustment for any stock splits, reverse splits, stock dividends or similar events affecting the Class A Common Stock; and (b) if the Class A Common Stock no longer trades on a securities exchange or automated or electronic quotation system, then a majority of the independent members of the board of directors of IPOco shall determine the fair market value of a share of Class A Common Stock in good faith.

“True-up Adjustment” has the meaning set forth in Section 2.1(h) of this Agreement.

“True-up Adjustment Amount” means a number of shares of Class A Common Stock equal to the difference between (i) the number of shares of Class A Common Stock that would have been paid to or withheld from a Holder pursuant to a Liquidation Adjustment in connection with a contingent Election of Exchange tendered by a Holder pursuant to Section 2.1(c) utilizing the average price of shares of Class A Common Stock sold by a Holder in connection with the satisfaction of the contingency that triggered the Exchange (“Transaction Price”) and (ii) the Initial True-up Amount.

Notwithstanding anything to the contrary in this Article II, any Cash Exchange Payment or shares of Class A Common Stock delivered to a Holder upon an Exchange shall be adjusted to the extent that section 4.1(b) of the LP Agreement would result in an adjustment to a distribution that would otherwise be made to such Holder in respect of the Partnership Interests to be Exchanged upon a liquidation of Holdings (a “Liquidation Adjustment”). To the extent that the Liquidation Adjustment would result in an increase in the liquidating distribution that would be made by Holdings to such Holder (an “Excess Amount”), the consideration to be received for the Paired Interests tendered for Exchange by such Holder shall be increased by (i) in the event of a Cash Exchange Payment, an amount of cash equal to such Excess Amount, and (ii) in the event shares of Class A Common Stock are to be delivered to a Holder, a number of shares of Class A

Common Stock equal to such Excess Amount divided by the Liquidation Adjustment Price. To the extent that the Liquidation Adjustment would result in a reduction in the liquidating distribution that would be made by Holdings to such Holder (a “Deficit Amount”), the consideration to be received for the Paired Interests tendered for Exchange by such Holder shall be decreased by (x) in the event of a Cash Exchange Payment, an amount of cash equal to such Deficit Amount and (y) in the event shares of Class A Common Stock are to be delivered to a Holder, a number of shares of Class A Common Stock equal to such Deficit Amount divided by the Liquidation Adjustment Price; provided, however, that if such Holder instead elects to make a contemporaneous cash contribution to Holdings equal to such Deficit Amount, there shall be no Deficit Amount with respect to such Holder for purposes of this Section 2.1(h). Notwithstanding anything to the contrary in this Section 2.1(h), if the Holder submits an Election of Exchange pursuant to Section 2.1(c) of this Agreement that is contingent upon a future transaction, the Liquidation Adjustment will be settled through use of an Initial True-Up Amount and a True-Up Adjustment Amount. If the per share price used by IPOco to determine the Initial True-up Amount in connection with a contingent Election of Exchange tendered by a Holder pursuant to Section 2.1(c) of this Agreement differs from the Transaction Price, then any shares of Class A Common Stock paid to or withheld from the Holder in connection with the Initial True-up Amount, if any, shall be subject to a further adjustment by IPOco using the True-up Adjustment Amount in order to properly reflect the principles set forth in this Section 2.1(h) and the definition of “True-Up Adjustment Amount” (a “True-up Adjustment”). In connection with a True-up Adjustment, if the True-up Adjustment Amount is negative then IPOco (or Holdings, as IPOco may determine in its sole discretion), shall pay to the Holder an amount in cash, shares of Class A Common Stock or a combination thereof, as determined by IPOco in its sole discretion, equal to the absolute value of the True-up Adjustment Amount with any such amount to be paid in cash calculated using the Transaction Price as the per share price. In connection with a True-up Adjustment, if the True-up Adjustment Amount is positive, then the Holder shall pay to IPOco (or Holdings, as IPOco may determine in its sole discretion), an amount in cash, equal to the True-up Adjustment Amount multiplied by the Transaction Price. Notwithstanding anything to the contrary in this Section 2.1(h), IPOco shall have the authority to put such procedures in place and take such actions, including without limitation amending or interpreting this agreement and implementing Liquidation Adjustments using the Initial True-up Amount upon the submission by a Holder of a contingent Election of Exchange pursuant to Section 2.1(c) of this Agreement, in IPOco’s sole discretion as it determines in good faith is required to properly reflect the principles set forth in this Section 2.1(h) and the definition of “True-Up Adjustment Amount.”

(a)If to IPOco, to:

Core and Main, Inc.

1830 Craig Park Court
St. Louis, Missouri 63146
E-mail:     Mark.Whittenburg@coreandmain.com
Attention: General Counsel and Secretary

with a copy (which shall not constitute notice) to:

Debevoise and Plimpton LLP
66 Hudson Boulevard,

New York, New York 10001

E-mail: pmrodel@debevoise.com
Attention: Paul M. Rodel, Esq.

(b)If to Holdings, to:

Core & Main Holdings, LP
c/o Core and Main, Inc.

1830 Craig Park Court
St. Louis, Missouri 63146
E-mail:     Mark.Whittenburg@coreandmain.com
Attention: General Counsel and Secretary

with a copy (which shall not constitute notice) to:

Debevoise and Plimpton LLP
66 Hudson Boulevard,

New York, New York 10001

E-mail: pmrodel@debevoise.com
Attention: Paul M. Rodel, Esq.

(c)If to CD&R Waterworks Holdings, addressed to it at:

CD&R Waterworks Holdings, LLC
c/o Clayton, Dubilier & Rice, LLC

375 Park Ave., 18th Floor
New York, New York 10152
E-mail: RSimson@cdr-inc.com
Attention: Rima Simson

and

with a copy (which shall not constitute notice) to:

Debevoise and Plimpton LLP
66 Hudson Boulevard,

New York, New York 10001

E-mail: pmrodel@debevoise.com
Attention: Paul M. Rodel, Esq.

(d)If to Management Feeder, addressed to it at:

Core & Main Management Feeder, LLC
c/o Core and Main, Inc.

1830 Craig Park Court
St. Louis, Missouri 63146
E-mail:     Mark.Whittenburg@coreandmain.com
Attention: General Counsel and Secretary

and

with a copy (which shall not constitute notice) to:

Debevoise and Plimpton LLP
66 Hudson Boulevard,

New York, New York 10001

E-mail: pmrodel@debevoise.com
Attention: Paul M. Rodel, Esq.

(e)If to any Holder other than the Continuing Limited Partners, to the address and other contact information set forth in the records of IPOco or Holdings from time to time.

CORE & MAIN, INC.

By: /s/ Stephen O. LeClair    
    Name: Stephen O. LeClair
    Title: Chief Executive Officer    
    

CORE & MAIN HOLDINGS, LP

By: /s/ Stephen O. LeClair    
    Name: Stephen O. LeClair
    Title: Chief Executive Officer    
    

CD&R WATERWORKS HOLDINGS, LLC

By: CD&R Waterworks Holdings, L.P., its manager
By: CD&R Waterworks Holdings GP, Ltd., its general partner

By: /s/ Rima Simson    
    Name: Rima Simson
    Title: Vice President, Treasurer and     Secretary

CORE & MAIN MANAGEMENT FEEDER, LLC

By: /s/ Mark R. Witkowski    
    Name: Mark R. Witkowski
    Title: Vice President