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                                                                   Exhibit 4.6.1
                          FIRST SUPPLEMENTAL INDENTURE

         This First Supplemental Indenture, dated as of January 17, 2000, is
between DAYTON SUPERIOR CORPORATION, an Ohio corporation (the "Company"), and
FIRSTAR BANK, N.A., as trustee (the "Trustee").

                                   WITNESSETH:

                  WHEREAS, the Company and the Trustee entered into a Junior
         Convertible Subordinated Indenture dated as of October 5, 1999 (the
         "Indenture"), authorizing the issuance of the Company's 10% Convertible
         Subordinated Debentures due September 30, 2029 (the "Debentures");

                  WHEREAS, Section 9.1 of the Indenture permits the Company and
         the Trustee to enter into one or more indentures supplemental to the
         Indenture for the purpose of curing any ambiguity, correcting or
         supplementing any provision in the Indenture that may be inconsistent
         with any other provision in the Indenture, or making any other
         provisions with respect to matters or questions arising under the
         Indenture, so long as any such action does not materially adversely
         affect the interest of the holders of the Debentures and, for so long
         as any of the preferred securities of Dayton Superior Capital Trust are
         outstanding, the holders of such preferred securities; and

                  WHEREAS, the Company desires to clarify the provisions of the
         Indenture relating to the conversion features of the Debentures in the
         event of certain merger, reclassifications and other transactions
         involving the Company, and such clarifying language does not materially
         adversely affect the interest of the holders of the Debentures or the
         holders of the preferred securities of Dayton Superior Capital Trust;

         NOW, THEREFORE, in consideration of the premises and of the mutual
agreements herein contained and contained in the Indenture, the Company and the
Trustee agree as follows:

         SECTION 1. Section 13.5(a) of the Indenture is hereby amended in its
entirety to read as follows:

                  "(a) In the event that the Company is a party to any
         transaction (including, without limitation, a merger other than a
         merger that does not result in a reclassification, conversion, exchange
         or cancellation of Common Stock), consolidation, sale of all or
         substantially all of the assets of the Company, recapitalization or
         reclassification of Common Stock (other than a change in par value, or
         from par value to no par value, or from no par value to par value or as
         a result of a subdivision or combination of Common Stock) or any
         compulsory share exchange (each of the foregoing being referred to as a
         "TRANSACTION"), in each case, as a result of which shares of Common
         Stock shall be

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         converted into the right to receive, or shall be exchanged for, (i) in
         the case of any Transaction other than a Transaction involving a Common
         Stock Fundamental Change (and subject to funds being legally available
         for such purpose under applicable law and the time of such conversion),
         securities, cash or other property, each Debenture shall thereafter be
         convertible into the kind and amount of securities, cash and other
         property receivable upon the consummation of such Transaction by a
         holder of that number of shares of Common Stock into which a Debenture
         was convertible immediately prior to such Transaction, or (ii) in the
         case of a Transaction involving a Common Stock Fundamental Change,
         common stock, each Debenture shall thereafter be convertible (in the
         manner described herein) into common stock of the kind received by
         holders of Common Stock (but in each case after giving effect to any
         adjustment discussed in paragraphs (b) and (c) relating to a
         Fundamental Change if such Transaction constitutes a Fundamental
         Change). The holders of Debentures or Preferred Securities will have no
         voting rights with respect to any Transaction."

         SECTION 2. This First Supplemental Indenture shall become effective on
the date first set forth above.

         SECTION 3. Except as specifically amended hereby, all of the terms and
conditions of the Indenture shall remain in full force and effect and unamended
hereby. No reference to this First Supplemental Indenture need be made in any
instrument or document at any time referring to the Indenture, a reference to
the Indenture in any of such to be deemed to be reference to the Indenture as
amended hereby. This First Supplemental Indenture may be executed in any number
of counterparts and by separate parties hereto on separate counterparts, each of
which when executed shall be deemed an original, but all such counterparts taken
together shall constitute one and the same instrument.

         IN WITNESS WHEREOF, the parties hereto have caused this First
Supplemental Indenture to be duly executed, and their respective seals to be
hereunder affixed and attested, all as of the day and year first written above.

                              DAYTON SUPERIOR CORPORATION
(SEAL)
                              By  /s/ ALAN F. MCILROY
Attest:                             Name: Alan F. McIlroy
                                    Title: Vice President and Chief
/s/ Jaime Taronji, Jr.                     Financial Officer
     Secretary

                              FIRSTAR BANK, N.A., as Trustee
(SEAL)
                              By: /s/ KEITH A MAURMEIER
Attest:                             Name:  Keith A. Maurmeier
                                    Title: Vice President and Trust Officer


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