POWER OF ATTORNEY

        Know all by these presents that the undersigned hereby constitutes and
appoints each of Russell Becker and Andrea Fike, signing singly, the
undersigned's true and lawful attorney-in-fact to:

    1.  execute for and on behalf of the undersigned, in the undersigned's
        capacity as an officer and/or director of APi Group Corporation (the
        "Company"), Form ID, including other documents necessary to obtain EDGAR
        codes and passwords enabling the undersigned to make electronic filings
        with the United States Securities and Exchange Commission (the
        "Commission") and Forms 3, 4 and 5 in accordance with Section 16(a) of
        the Securities Exchange Act of 1934, as amended (the "Exchange Act"),
        and the rules thereunder (collectively, the "Required Filings");

    2.  do and perform any and all acts for and on behalf of the undersigned
        which may be necessary or desirable to complete and execute any such
        Required Filings, complete and execute any amendment or amendments
        thereto, and timely file such form with the Commission and any stock
        exchange or similar authority; and

    3.  take any other action of any type whatsoever in connection with the
        foregoing which, in the opinion of such attorney-in-fact, may be of
        benefit to, in the best interest of, or legally required by, the
        undersigned, it being understood that the documents executed by such
        attorney-in-fact on behalf of the undersigned pursuant to this Power of
        Attorney shall be in such form and shall contain such terms and
        conditions as such attorney-in-fact may approve in such attorney-in-
        fact's discretion.

        The undersigned hereby grants to each such attorney-in-fact full power
and authority to do and perform any and every act and thing whatsoever
requisite, necessary, or proper to be done in the exercise of any of the rights
and powers herein granted, as fully to all intents and purposes as the
undersigned might or could do if personally present, with full power of
substitution or revocation, hereby ratifying and confirming all that such
attorney-in-fact, or such attorney-in-facts substitute or substitutes, shall
lawfully do or cause to be done by virtue of this Power of Attorney and the
rights and powers herein granted. The undersigned acknowledges that the
foregoing attorneys-in-fact, in serving in such capacity at the request of the
undersigned, are not assuming, nor is the Company assuming, any of the
undersigned's responsibilities to comply with Section 16 of the Exchange Act.

        The undersigned hereby revokes all previous powers of attorney that have
been granted by him in connection with his reporting obligations, if any, under
Section 16 of the Exchange Act with respect to his holdings of and transactions
in securities issued by the Company. This Power of Attorney shall remain in full
force and effect until the undersigned is no longer required to file Forms 3, 4
and 5 with respect to the undersigned's holdings of and transactions in
securities issued by the Company, unless earlier revoked by the undersigned in a
signed writing delivered to the foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of February 24, 2020.


By:     /s/ Thomas A. Lydon
        -------------------
Name:   Thomas A. Lydon