Exhibit 31(b)
I, John D. Milton, Jr., certify that:

1.	I have reviewed this quarterly report on Form 10-Q of Florida Rock
Industries, Inc.;

2.	Based on my knowledge, this report does not contain any untrue statement of
a material fact or omit to state a material fact necessary to make the
statements made, in light of the circumstances under which such statements
were made, not misleading with respect to the period covered by this report;

3.	Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material respects
the financial condition, results of operations and cash flows of the company
as of, and for, the periods presented in this report;

4.	The company's other certifying officers and I are responsible for
establishing and maintaining disclosure controls and procedures (as defined
in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over
financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-
15(f))for the company and have:

a.	designed such disclosure controls and procedures, or caused such
disclosure controls and procedures to be designed under our
supervision, to ensure that material information relating to the
company, including its consolidated subsidiaries, is made known to us
by others within those entities, particularly during the period in
which this report is being prepared;

b.	designed such internal control over financial reporting, or caused such
internal control over financial reporting to be designed under our
supervision to provide reasonable assurance regarding the reliability
of financial reporting and the preparation of financial statements for
external purposes in accordance with generally accepted accounting
principles;

c.	evaluated the effectiveness of the company's disclosure controls and
procedures and presented in this report our conclusions about the
effectiveness of the disclosures controls and procedures, as of the end
of the period covered by this report based on such evaluation; and

d.	disclosed in this report any change in the company's internal control
over financial reporting that occurred during the company's most recent
fiscal quarter (the registrant's fourth fiscal quarter in the case of
an annual report) that has materially affected, or is reasonably likely
to materially affect, the company's internal control over financial
reporting and

5.	The company's other certifying officers and I have disclosed, based on our
most recent evaluation of internal control over financial reporting, to the
company's auditors and the audit committee of the company's board of
directors (or persons performing the equivalent functions):

a.	all significant deficiencies and material weaknesses in the design or
operation of internal controls over financial reporting which are
reasonably likely to adversely affect the company's ability to record,
process, summarize and report financial information and

b.	any fraud, whether or not material, that involves management or other
employees who have a significant role in the company's internal control
over financial reporting.

Date:  May 2, 2007

                                       JOHN D. MILTON, JR.
                                       JOHN D. MILTON, JR.
				       Executive Vice President,
                                        Treasurer and Chief Financial
                                        Officer