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                       UNCONDITIONAL GUARANTY OF PAYMENT AND PERFORMANCE


     FOR AND IN CONSIDERATION OF the sum of Ten and No/100 Dollars ($10.00)
and other good and valuable consideration paid or delivered to the undersigned
STORAGE TRUST REALTY, a Maryland real estate investment trust (hereinafter
referred to as "Guarantor"), the receipt and sufficiency whereof are hereby
acknowledged by Guarantor, and for the purpose of seeking to induce THE FIRST
NATIONAL BANK OF BOSTON, a national banking association (hereinafter referred
to as "FNBB"), BANK OF AMERICA ILLINOIS, an Illinois banking corporation
(hereinafter referred to as "BOA"; FNBB and BOA are hereinafter referred to
collectively as "Lender", which term shall also include each other Bank which
may now or hereafter become party to the "Credit Agreement" (as hereinafter
defined) and shall also include any such individual Bank acting as agent for
all of the Banks), to extend credit or otherwise provide financial
accommodations to STORAGE TRUST PROPERTIES, L.P., a Delaware limited
partnership (hereinafter referred to as "Borrower"), which extension of credit
and provision of financial accommodations will be to the direct interest,
advantage and benefit of Guarantor, Guarantor does hereby absolutely,
unconditionally and irrevocably guarantee to Lender:

(a)   the full and prompt payment when due, whether by acceleration or
otherwise, either before or after maturity thereof, of that certain Note of
even date herewith made by Borrower to the order of FNBB in the principal face
amount of Sixty-Two Million Five Hundred Thousand and No/100 Dollars
($62,500,000.00) and that certain Swing Loan Note of even date herewith made
by Borrower to the order of FNBB in the principal face amount of Ten Million
and No/100 Dollars ($10,000,000.00) (hereinafter referred to collectively as
the "FNBB Note") together with interest as provided in the FNBB Note, together
with any replacements, supplements, renewals, modifications, consolidations,
restatements and extensions thereof; and

(b)   the full and prompt payment when due, whether by acceleration or
otherwise, either before or after maturity thereof, of that certain Note of
even date herewith made by Borrower to the order of BOA in the principal face
amount of Thirty-Seven Million Five Hundred Thousand and No/100 Dollars
($37,500,000.00) (hereinafter referred to as the "BOA Note") together with
interest as provided in the BOA Note, together with any replacements,
supplements, renewals, modifications, consolidations, restatements and
extensions thereof; and

(c)   the full and prompt payment when due, whether by acceleration or
otherwise, either before or after maturity thereof, of each other note as may
be issued under that certain Revolving Credit Agreement dated of even date
herewith (hereinafter referred to as the "Credit Agreement") among Borrower,
FNBB, for itself and as agent, and BOA, together with interest as provided in
each such note, together with any replacements, supplements, renewals,
modifications, consolidations, restatements and extensions thereof (the FNBB
Note, the BOA Note and each of the notes described in this subparagraph (c) is
hereinafter referred to collectively as the "Note"); and


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(d)   the full and prompt payment and performance of all obligations of
Borrower to Lender under the terms of the Credit Agreement, together with any
replacements, supplements, renewals, modifications, consolidations,
restatements and extensions thereof; and

(e)   the full and prompt payment and performance of any and all other
obligations of Borrower to Lender under any other agreements, documents or
instruments now or hereafter evidencing, securing or otherwise relating to the
indebtedness evidenced by the Note or the Credit Agreement (the Note, the
Credit Agreement and said other agreements, documents and instruments, are
hereinafter collectively referred to as the "Loan Documents" and individually
referred to as a "Loan Document").  All terms used herein and not otherwise
defined herein shall have the meanings set forth in the Credit Agreement.

      1.    Agreement to Pay and Perform; Costs of Collection.  Guarantor does
hereby agree that if the Note is not paid by Borrower in accordance with its
terms, or if any and all sums which are now or may hereafter become due from
Borrower to Lender under the Loan Documents are not paid by Borrower in
accordance with their terms, or if any and all other obligations of Borrower
to Lender under the Note and the Loan Documents are not performed by Borrower
in accordance with their terms, Guarantor will immediately make such payments
and perform such obligations.  Guarantor further agrees to pay Lender on
demand all reasonable costs and expenses (including court costs and reasonable
attorneys' fees and disbursements) paid or incurred by Lender in endeavoring
to collect the indebtedness guaranteed hereby, to enforce any of the other
obligations of Borrower guaranteed hereby, or any portion thereof, or to
enforce this Guaranty, and until paid to Lender, such sums shall bear interest
at the default rate set forth in the Credit Agreement unless collection from
Guarantor of interest at such rate would be contrary to applicable law, in
which event such sums shall bear interest at the highest rate which may be
collected from Guarantor under applicable law.

     2.    Reinstatement of Refunded Payments.  If, for any reason, any
payment to Lender of any of the obligations guaranteed hereunder is required
to be refunded by Lender to Borrower, or paid or turned over to any other
person, including, without limitation, by reason of the operation of
bankruptcy, reorganization, receivership or insolvency laws or similar laws of
general application relating to creditors' rights and remedies now or
hereafter enacted, Guarantor agrees to pay the amount so required to be
refunded, paid or turned over (the "Turnover Payment"), the obligations of
Guarantor shall not be treated as having been discharged by the original
payment to Lender giving rise to the Turnover Payment, and this Guaranty shall
be treated as having remained in full force and effect for any such Turnover
Payment so made by Lender, as well as for any amounts not theretofore paid to
Lender on account of such obligations.

     3.    Rights of Lender to Deal with Collateral, Borrower and Other
Persons.  Guarantor hereby consents and agrees that Lender may at any time,
and from time to time, without thereby releasing Guarantor from any liability
hereunder and without notice to or further consent from Guarantor, either with
or without consideration:  release or surrender any lien or other security of
any kind or nature whatsoever held by it or by any person, firm or corporation

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on its behalf or for its account, securing any indebtedness or liability
hereby guaranteed; substitute for any collateral so held by it, other
collateral of like kind, or of any kind; modify the terms of the Note or the
Loan Documents; extend or renew the Note for any period; grant releases,
compromises and indulgences with respect to the Note or the Loan Documents and
to any persons or entities now or hereafter liable thereunder or hereunder;
release any other Guarantor, surety, endorser or accommodation party of the
Note or any other Loan Documents; or take or fail to take any action of any
type whatsoever.  No such action which Lender shall take or fail to take in
connection with the Note or the Loan Documents, or any of them, or any
security for the payment of the indebtedness of Borrower to Lender or for the
performance of any obligations or undertakings of Borrower, nor any course of
dealing with Borrower or any other person, shall release Guarantor's
obligations hereunder, affect this Guaranty in any way or afford Guarantor any
recourse against Lender.  The provisions of this Guaranty shall extend and be
applicable to all replacements, supplements, renewals, amendments, extensions,
consolidations, restatements and modifications of the Note and the Loan
Documents, and any and all references herein to the Note and the Loan
Documents shall be deemed to include any such replacements, supplements,
renewals, extensions, amendments, consolidations, restatements or
modifications thereof.  Without limiting the generality of the foregoing,
Guarantor acknowledges the terms of Section 18.3 of the Credit Agreement and
agrees that this Guaranty shall extend and be applicable to each new or
replacement note delivered by Borrower pursuant thereto without notice to or
further consent from Guarantor.

     4.    No Contest with Lender; Subordination.  So long as any obligation
hereby guaranteed remains unpaid or undischarged, Guarantor will not, by
paying any sum recoverable hereunder (whether or not demanded by Lender) or by
any means or on any other ground, claim any set-off or counterclaim against
Borrower in respect of any liability of Guarantor to Borrower or, in
proceedings under federal bankruptcy law or insolvency proceedings of any
nature, prove in competition with Lender in respect of any payment hereunder
or be entitled to have the benefit of any counterclaim or proof of claim or
dividend or payment by or on behalf of Borrower or the benefit of any other
security for any obligation hereby guaranteed which, now or hereafter, Lender
may hold or in which it may have any share. Guarantor hereby expressly waives
any right of contribution from or indemnity against Borrower, whether at law
or in equity, arising from any payments made by Guarantor pursuant to the
terms of this Guaranty, and Guarantor acknowledges that Guarantor has no right
whatsoever to proceed against Borrower for reimbursement of any such payments.
In connection with the foregoing, Guarantor expressly waives any and all
rights of subrogation to Lender against Borrower, and Guarantor hereby waives
any rights to enforce any remedy which Lender may have against Borrower and
any rights to participate in any collateral for Borrower's obligations under
the Loan Documents.  Guarantor hereby subordinates any and all indebtedness of
Borrower now or hereafter owed to Guarantor to all indebtedness of Borrower to
Lender, and agrees with Lender that (a) Guarantor shall not demand or accept
any payment from Borrower on account of such indebtedness, (b) Guarantor shall
not claim any offset or other reduction of Guarantor's obligations hereunder
because of any such indebtedness, and (c) Guarantor shall not take any action
to obtain any interest in any of the security described in and encumbered by


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the Loan Documents because of any such indebtedness; provided, however, that,
if Lender so requests, such indebtedness shall be collected, enforced and
received by Guarantor as trustee for Lender and be paid over to Lender on
account of the indebtedness of Borrower to Lender, but without reducing or
affecting in any manner the liability of Guarantor under the other provisions
of this Guaranty except to the extent the principal amount of such outstanding
indebtedness shall have been reduced by such payment.

     5.    Waiver of Defenses.  Guarantor hereby agrees that its obligations
hereunder shall not be affected or impaired by, and hereby waives and agrees
not to assert or take advantage of any defense based on:

     (a)   any statute of limitations in any action hereunder or for
the collection of the Note or for the payment or performance of any obligation
hereby guaranteed;

     (b)   the incapacity or lack of authority of Borrower or any other
person or entity, or the failure of Lender to file or enforce a claim against
the estate (either in administration, bankruptcy or in any other proceeding)
of Borrower or Guarantor or any other person or entity;

     (c)   the dissolution or termination of existence of Borrower or
Guarantor;

     (d)   the voluntary or involuntary liquidation, sale or other
disposition of all or substantially all of the assets of Borrower;

     (e)   the voluntary or involuntary receivership, insolvency,
bankruptcy, assignment for the benefit of creditors, reorganization,
assignment, composition, or readjustment of, or any similar proceeding
affecting, Borrower or Guarantor, or any of Borrower's or Guarantor's
properties or assets;

     (f)   the damage, destruction, condemnation, foreclosure or
surrender of all or any part of the Real Estate or any of the improvements
located thereon;

     (g)   the failure of Lender to give notice of the existence,
creation or incurring of any new or additional indebtedness or obligation or
of any action or nonaction on the part of any other person whomsoever in
connection with any obligation hereby guaranteed;

     (h)   any failure or delay of Lender to commence an action against
Borrower, to assert or enforce any remedies against Borrower under the Note or
the Loan Documents, or to realize upon any security;

     (i)   any failure of any duty on the part of Lender to disclose to
Guarantor any facts it may now or hereafter know regarding Borrower, the Real
Estate or any of the improvements located thereon, whether such facts
materially increase the risk to Guarantor or not;


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     (j)   failure to accept or give notice of acceptance of this
Guaranty by Lender;

     (k)   failure to make or give notice of presentment and demand for
payment of any of the indebtedness or performance of any of the obligations
hereby guaranteed;

     (l)   failure to make or give protest and notice of dishonor or of
defult to Guarantor or to any other party with respect to the indebtedness or
performance of obligations hereby guaranteed;

    (m)   except as otherwise specifically provided in this Guaranty,
any and all other notices whatsoever to which Guarantor might otherwise be
entitled;

    (n)   any lack of diligence by Lender in collection, protection or
realization upon any collateral securing the payment of the indebtedness or
performance of obligations hereby guaranteed;

    (o)   the invalidity or unenforceability of the Note or any of the
Loan Documents;

    (p)   the compromise, settlement, release or termination of any or
all of the obligations of Borrower under the Note or the Loan Documents;

    (q)   any transfer by Borrower of all or any part of the security
encumbered by the Loan Documents;

    (r)   the failure of Lender to perfect any security or to extend
or renew the perfection of any security; or

    (s)   to the fullest extent permitted by law, any other legal,
equitable or surety defenses whatsoever to which Guarantor might otherwise be
entitled (other than the defense of payment), it being the intention that the
obligations of Guarantor hereunder are absolute, unconditional and
irrevocable.

     6.    Guaranty of Payment and Performance and Not of Collection.  This
is a Guaranty of payment and performance and not of collection.  The liability
of Guarantor under this Guaranty shall be primary, direct and immediate and
not conditional or contingent upon the pursuit of any remedies against
Borrower or any other person, nor against securities or liens available to
Lender, its successors, successors in title, endorsees or assigns.  Guarantor
hereby waives any right to require that an action be brought against Borrower
or any other person or to require that resort be had to any security or to any
balance of any deposit account or credit on the books of Lender in favor of
Borrower or any other person.

     7.    Rights and Remedies of Lender.  In the event of a default under
the Note or the Loan Documents, or any of them, Lender shall have the right to
enforce its rights, powers and remedies thereunder or hereunder or under any
other agreement, document or instrument now or hereafter evidencing, securing

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or otherwise relating to the indebtedness evidenced by the Note or secured by
the Loan Documents, in any order, and all rights, powers and remedies
available to Lender in such event shall be nonexclusive and cumulative of all
other rights, powers and remedies provided thereunder or hereunder or by law
or in equity.  Accordingly, Guarantor hereby authorizes and empowers Lender
upon the occurrence of any event of default under the Note or the Loan
Documents, at its sole discretion, and without notice to Guarantor, to
exercise any right or remedy which Lender may have, including, but not limited
to, judicial foreclosure, exercise of rights of power of sale, acceptance of a
deed or assignment in lieu of foreclosure, appointment of a receiver to
collect rents and profits, exercise of remedies against personal property, or
enforcement of any assignment of leases, as to any security, whether real,
personal or intangible.  At any public or private sale of any security or
collateral for any indebtedness or any part thereof guaranteed hereby, whether
by foreclosure or otherwise, Lender may, in its discretion, purchase all or
any part of such security or collateral so sold or offered for sale for its
own account and may apply against the amount bid therefor all or any part of
the balance due it pursuant to the terms of the Note or any other Loan
Document without prejudice to Lender's remedies hereunder against Guarantor
for deficiencies.  If the indebtedness guaranteed hereby is partially paid by
reason of the election of Lender to pursue any of the remedies available to
Lender, or if such indebtedness is otherwise partially paid, this Guaranty
shall nevertheless remain in full force and effect, and Guarantor shall remain
liable for the entire balance of the indebtedness guaranteed hereby even
though any rights which Guarantor may have against Borrower may be destroyed
or diminished by the exercise of any such remedy.

     8.    Application of Payments.  Guarantor hereby authorizes Lender,
without notice to Guarantor, to apply all payments and credits received from
Borrower or from Guarantor or realized from any security in such manner and in
such priority as Lender in its sole judgment shall see fit to the
indebtedness, obligation and undertakings which are the subject of this
Guaranty.

     9.    Business Failure, Bankruptcy or Insolvency.  In the event of the
business failure of Guarantor or if there shall be pending any bankruptcy or
insolvency case or proceeding with respect to Guarantor under federal
bankruptcy law or any other applicable law or in connection with the
insolvency of Guarantor, or if a liquidator, receiver, or trustee shall have
been appointed for Guarantor or Guarantor's properties or assets, Lender may
file such proofs of claim and other papers or documents as may be necessary or
advisable in order to have the claims of Lender allowed in any proceedings
relative to Guarantor, or any of Guarantor's properties or assets, and,
irrespective of whether the indebtedness or other obligations of Borrower
guaranteed hereby shall then be due and payable, by declaration or otherwise,
Lender shall be entitled and empowered to file and prove a claim for the whole
amount of any sums or sums owing with respect to the indebtedness or other
obligations of Borrower guaranteed hereby, and to collect and receive any
moneys or other property payable or deliverable on any such claim.  Guarantor
covenants and agrees that upon the commencement of a voluntary or involuntary
bankruptcy proceeding by or against Borrower, Guarantor shall not seek a
supplemental stay or otherwise pursuant to 11 U.S.C. 105 or any other


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provision of the Bankruptcy Reform Act of 1978, as amended, or any other
debtor relief law (whether statutory, common law, case law, or otherwise) of
any jurisdiction whatsoever, now or hereafter in effect, which may be or
become applicable, to stay, interdict, condition, reduce or inhibit the
ability of Lender to enforce any rights of Lender against Guarantor by virtue
of this Guaranty or otherwise.

     10.   Financial Statements and Other Information.  Guarantor hereby
represents and warrants to Lender that all financial statements of Guarantor
heretofore delivered by Guarantor to Lender are true and correct in all
material respects, have been prepared in accordance with generally accepted
accounting principles consistently applied, and fairly present the financial
condition of Guarantor as at the close of business on the date thereof and the
results of operations for the period then ended; that no material adverse
change has occurred in the assets, liabilities, financial condition or
business of Guarantor as shown or reflected therein since the date thereof;
and that Guarantor has no liabilities or known contingent liabilities
involving material amounts which are not reflected in such financial
statements or referred to in the notes thereto other than Guarantor's
obligations under this Guaranty.  Guarantor hereby agrees that until all
indebtedness guaranteed hereby has been completely repaid, all obligations and
undertakings of Borrower under, by reason of, or pursuant to the Note and the
Loan Documents have been completely performed and Lender has no further
obligation to make Loans to Borrower pursuant to the Credit Agreement,

Guarantor will deliver to Lender:

     (a)   as soon as practicable and in any event within 90 days after
the end of each fiscal year of Guarantor, the audited consolidated balance
sheet of Guarantor and its Subsidiaries as of the end of such year, and the
related audited consolidated statement of operations and statement of cash
flows for such year, each setting forth in comparative form the figures for
the previous fiscal year and all such statements to be in reasonable detail,
prepared in accordance with generally accepted accounting principles, and
accompanied by an auditor's report prepared without qualification by Ernst &
Young or by another "Big Six" accounting firm, the Form 10-K filed with the
SEC (unless the SEC has approved an extension, in which event the Guarantor
will deliver to each Lender a copy of the Form 10-K simultaneously with
delivery to the SEC).  At any time that the Agent has reasonable grounds to
request the same (including, without limitation, at any time that the
Compliance Certificate indicates that the Guarantor is at or near the minimum
compliance with the financial covenants in this Guaranty), the Agent may
require that such report be accompanied by a written statement from such
accountants to the effect that they have read a copy of this Guaranty and the
Credit Agreement, and that, in making the examination necessary to said
certification, they have obtained no knowledge of any Default or Event of
Default under this Guaranty, or, if such accountants shall have obtained
knowledge of any then existing Default or Event of Default they shall disclose
in such statement any such Default or Event of Default;

     (b)   as soon as practicable and in any event within 60 days after
the end of each of the first three fiscal quarters of Guarantor, copies of the
unaudited consolidated balance sheet of Guarantor and its Subsidiaries as of

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the end of such quarter, and the related unaudited consolidated statement of
operations and statement of cash flows for the portion of Guarantor's fiscal
year then elapsed, all in reasonable detail and prepared in accordance with
generally accepted accounting principles (which may be provided by inclusion
in the Form 10-Q of the Guarantor for such period provided pursuant to
subsection (c) below), together with a certification by the principal
financial or accounting officer of Guarantor that the information contained in
such financial statements fairly presents the financial position of Guarantor
and its Subsidiaries on the date thereof (subject to year end adjustment);

    (c)   contemporaneously with the delivery of the financial
statements referred to in clause (a) above, a statement of all contingent
liabilities of Guarantor which are not reflected in such financial statements
or referred to in the notes thereto (including, without limitation, all
guarantees, endorsements and other contingent obligations in respect of
indebtedness of others, and obligations to reimburse the issuer in respect of
any letters of credit), and a statement of projected cash flows of Guarantor
for the current fiscal year, all in reasonable detail and certified by the
principal financial or accounting officer of Guarantor;

     (d)   contemporaneously with the filing or mailing thereof, copies
of all material of a financial nature filed with the SEC or sent to the
shareholders of Guarantor;

    (e)   as soon as practicable, but in any event not later than 60
days after the end of each fiscal quarter of the Guarantor (including the
fourth fiscal quarter in each year), copies of Form 10-Q filed with the SEC
(unless the SEC has approved an extension in which event the Guarantor will
deliver such copies of the Form 10-Q to each of Lender simultaneously with
delivery to the SEC);

    (f)   promptly after they are filed with the Internal Revenue
Service, copies of all annual federal income tax returns and amendments
thereto of Guarantor;

    (g)   not later than 60 days after the end of each fiscal quarter
of Guarantor (including the fourth fiscal quarter in each year), a statement,
certified as true and correct by the principal financial or accounting officer
of Guarantor, of all Indebtedness of Guarantor as of the end of such fiscal
quarter, which statement shall include the original principal amount of such
Indebtedness and the current amount outstanding, the holder thereof, the
maturity date and any extension options, the interest rate, the collateral
provided for such Indebtedness and whether such Indebtedness is recourse or
non-recourse;

    (h)   concurrently with the delivery of the financial statements
described in subsections (b) and (e) above, a certificate signed by the
President or Chief Financial Officer of Guarantor to the effect that, having
read this Guaranty, and that based upon an examination which they deem
sufficient to enable them to make an informed statement, there does not exist
any Default or Event of Default, or if such Default or Event of Default has
occurred, specifying the facts with respect thereto;

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     (i)   not later than five (5) Business Days after the Guarantor
receives notice of the same from the Rating Agency or otherwise learns of the
same, notice of the issuance of any change in the rating by the Rating Agency
in respect of any debt of the Guarantor (including any change in an Implied
Rating), together with the details thereof, and of any announcement by the
Rating Agency that any such rating is "under review" or that any such rating
has been placed on a watch list or that any similar action has been taken by
the Rating Agency (collectively a "Rating Notice");

     (j)   promptly upon becoming aware thereof, written notice from
Guarantor of any event or condition which might have a material adverse effect
on the business, operations, assets, condition (financial or otherwise) or
prospects of Guarantor or the ability of Guarantor to perform under this
Guaranty (including but not limited to, litigation commenced or threatened in
writing against Guarantor, judgments rendered against Guarantor, liens filed
against any property of Guarantor, defaults claimed under indebtedness for
borrowed money for which Guarantor is primarily or secondarily liable, or
bankruptcy, insolvency or trustee or receivership proceedings commenced
against Guarantor), such notice to specify the nature and the period of
existence of such event or condition, the anticipated effect thereof, and what
action Guarantor is taking or proposes to take with respect thereto; and

     (k)   with reasonable promptness, such other information
respecting the business, operations, assets, liabilities and financial
condition of Guarantor as Lender may from time to time reasonably request.

     Notwithstanding anything herein to the contrary, Guarantor shall not be
required to deliver any statements or reports described in this Paragraph 10
to the extent the same are delivered to the Banks by the Borrower as and when
required by this Guaranty.  Guarantor will permit any officer designated by
Lender, at Guarantor's expense, to visit and inspect any of the properties of
Guarantor, to examine the records and books of account of Guarantor (and to
make copies thereof and extracts therefrom) and to discuss the affairs,
finances and accounts of Guarantor with, and to be advised as to the same by,
its officers, all at such reasonable times and intervals Lender may reasonably
request.

      11.   Covenants of Guarantor.  Guarantor hereby covenants and agrees
with Lender that until all indebtedness guaranteed hereby has been completely
repaid and all obligations and undertakings of Borrower under, by reason of,
or pursuant to the Note and the Loan Documents have been completely performed:

      (a)   Guarantor will, and will cause each of its Subsidiaries to,
do or cause to be done all things necessary to preserve and keep in full force
and effect its corporate or legal existence, material rights and franchises,
as applicable, to effect and maintain its foreign qualifications, licensing,
domestication or authorization, and to comply with all applicable laws and
regulations (including, without limitation, environmental laws);

      (b)   Guarantor will have as its sole business purpose being the
sole general partner of the Borrower and will own no assets other than its
general partnership interest in the Borrower, Short-term Investments and its


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ownership of the stock of the corporate general partners of Subsidiaries of
the Borrower;

      (c)   Guarantor will, and will cause each of its Subsidiaries to,
duly pay and discharge, before the same shall become in arrears, all taxes,
assessments and other governmental charges imposed upon it and its properties,
sales or activities, or upon the income or profits therefrom, as well as
claims for labor, material, or supplies which if unpaid might become a lien or
charge on any of its property; provided that any such tax, assessment, charge
or claim need not be paid if the validity or amount thereof shall currently be
contested in good faith by appropriate proceedings and if Guarantor or such
Subsidiary shall have set aside on its books adequate reserves with respect
thereto; and provided further that Guarantor or such Subsidiary shall pay all
such taxes, assessments, charges and claims forthwith upon the commencement of
proceedings to foreclose any lien that may have attached as security therefor;

     (d)   Guarantor will, and will cause each of its Subsidiaries to,
maintain and keep the properties used or deemed by it to be useful in its
business in first-class repair, working order and condition, and make or cause
to be made all necessary and proper repairs thereto and replacements thereof;

     (e)   Guarantor will, and will cause each of its Subsidiaries to,
maintain with financially sound and reputable insurers, insurance with respect
to its properties and business against such casualties and contingencies and
in such types and amounts as shall be in accordance with sound business
practices for companies in similar business similarly situated;

     (f)   Guarantor will keep, and will cause each of its Subsidiaries
to keep, complete, proper and accurate records and books of account in which
full, true and correct entries will be made in accordance with generally
accepted accounting principles consistent with the preparation of the
financial statements heretofore delivered to Lender and will maintain adequate
accounts and reserves for all taxes (including income taxes), all
depreciation, depletion, and amortization of its properties and the properties
of its Subsidiaries, all other contingencies, and all other proper reserves;

     (g)   Guarantor will not create, incur, assume, guarantee or be or
remain liable, contingently or otherwise, with respect to any Indebtedness
other than:

          (i)    Indebtedness to Lender arising under any of the Note,
the Loan Documents and this Guaranty;

          (ii)    current liabilities of Guarantor incurred in the
odinary course of business but not incurred through the borrowing of
money or the obtaining of credit except for credit on an open account
basis customarily extended and in fact extended in connection with
normal purchases of goods and services;

          (iii)    Indebtedness in respect of taxes, assessments and
governmental charges to the extent that payment therefor shall not at

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the time be required to be made in accordance with the provisions of
subparagraph (c) of this paragraph;

          (iv)    Indebtedness in respect of judgments or awards that have
been in force for less than the applicable period for taking an appeal
so long as execution is not levied thereunder or in respect of which
Guarantor shall at the time in good faith be prosecuting an appeal or
proceedings for review and in respect of which a stay of execution shall
have been obtained pending such appeal or review; and

         (v)      endorsements for collection, deposit or negotiation and
warranties of products or services, in each case incurred in the
ordinary course of business.

         (h)      Guarantor will not, and will not permit any of its
Subsidiaries to, create or incur or suffer to be created or incurred or to
exist any lien, encumbrance, mortgage, pledge, charge, restriction or other
security interest of any kind upon any of its property or assets of any
character whether now owned or hereafter acquired, or upon the income or
profits therefrom; or transfer any of such property or assets or the income or
profits therefrom for the purpose of subjecting the same to the payment of
Indebtedness or performance of any other obligation in priority of payment of
its general creditors; or acquire, or agree to have an option to acquire, any
property or assets upon conditional sale or other title retention or purchase
money security agreement, devise or arrangement; or suffer to exist for a
period of more than 30 days after the same shall have been incurred any
Indebtedness or claim or demand against it that if unpaid might by law or upon
bankruptcy or insolvency, or otherwise, be given any priority whatsoever over
its general creditors; or sell, assign, pledge or otherwise transfer any
accounts, contract rights, general intangibles, chattel paper or instruments,
with or without recourse, or incur or maintain any obligation to any holder of
Indebtedness of Guarantor or such Subsidiary which prohibits the creation or
maintenance of any lien securing the Obligations; provided that Guarantor and
any Subsidiary of Guarantor may create or incur or suffer to be created or
incurred or to exist:

          (i)    liens in favor of Guarantor on all or part of the assets
of Subsidiaries of Guarantor securing Indebtedness owing by Subsidiaries
of Guarantor to Guarantor;

          (ii)    liens to secure taxes, assessments and other
governmental charges or claims for labor, material or supplies in
respect of obligations not overdue;

         (iii)    liens with respect of judgments or awards, the
Indebtedness with respect to which is permitted by subparagraph (g)(iv)
of this paragraph;

          (iv)    liens in favor of Lender; and

           (v)    liens specifically permitted pursuant to Section 8.2 of
the Credit Agreement.

<PAGE>

            (i)   Guarantor will not, and will not permit any of its
Subsidiaries to, become a party to any merger, consolidation or other business
combination, or agree to effect any asset acquisition, stock acquisition or
other acquisition, except (A) the merger or consolidation or one or more of
the Subsidiaries of Guarantor with and into Guarantor, or (B) the merger or
consolidation of two or more Subsidiaries of Guarantor;

            (j)   Guarantor will not, and will not permit any of its
Subsidiaries to, become a party to or agree to or affect any disposition of
assets, other than Distributions to its shareholders as permitted in this
Guaranty;

           (k)   Guarantor will not make or permit to be made, by voluntary
or involuntary means, any transfer or encumbrance of its interest in Borrower,
or any dilution of its interest in Borrower;

           (l)   Guarantor shall contribute or otherwise downstream to
Borrower any cash or other assets received by Guarantor from third parties
(including, without limitation, the proceeds from any Debt Offering or Equity
Offering);

           (m)   The Guarantor shall at all times comply with all
requirements of applicable laws and regulations necessary to maintain REIT
Status and shall operate its business as described in the Prospectus and in
compliance with the terms and conditions of this Guaranty and the other Loan
Documents;

           (n)   Guarantor will be self-directed and will not retain or
otherwise rely on any other Person for investment advisory services;

           (o)   Guarantor shall not pay any Distribution to the shareholders
of the Guarantor if such Distribution is in excess of the amount which, when
added to the amount of all other Distributions paid in the same fiscal quarter
and the preceding three (3) fiscal quarters will exceed (I) ninety percent
(90%) of its Funds from Operations for the four (4) consecutive fiscal
quarters ending prior to the quarter in which such Distribution is paid, or
(ii) ninety-five percent (95%) of its Funds Available for Distribution for the
four (4) consecutive fiscal quarters ending prior to the quarter in which such
Distribution is paid.  The foregoing limitation on Distributions shall not
preclude the Guarantor from paying Distributions necessary to maintain its
REIT Status; and

            (p)   Guarantor will cooperate with Lender and execute such
further instruments and documents as Lender shall reasonably request to carry
out to their satisfaction the transactions contemplated by this Guaranty and
the other Loan Documents.

     12.   Security and Rights of Set-off.  Guarantor hereby grants to
Lender, as security for the full and prompt payment and performance of
Guarantor's obligations hereunder, a continuing lien on and security interest
in any and all securities or other property belonging to Guarantor now or
hereafter held by Lender and in any and all deposits (general or specific,


<PAGE>

time or demand, provisional or final, regardless of currency, maturity, or the
branch of Lender where the deposits are held) now or hereafter held by Lender
and other sums credited by or due from Lender to Guarantor or subject to
withdrawal by Guarantor; and regardless of the adequacy of any collateral or
other means of obtaining repayment of such obligations, during the continuance
of any Event of Default under the Note or the Loan Documents, Lender may at
any time and without notice to Guarantor set-off and apply the whole or any
portion or portions of any or all such deposits and other sums against amounts
payable under this Guaranty, whether or not any other person or persons could
also withdraw money therefrom.  Any security now or hereafter held by or for
Guarantor and provided by Borrower, or by anyone on Borrower's behalf, in
respect of liabilities of Guarantor hereunder shall be held in trust for
Lender as security for the liabilities of Guarantor hereunder.

     13.   Changes in Writing; No Revocation.  This Guaranty may not be
changed orally, and no obligation of Guarantor can be released or waived by
Lender except by a writing signed by a duly authorized officer of Lender.
This Guaranty shall be irrevocable by Guarantor until all indebtedness
guaranteed hereby has been completely repaid and all obligations and
undertakings of Borrower under, by reason of, or pursuant to the Note and the
Loan Documents have been completely performed.

     14.   Notices.  All notices, demands or requests provided for or
permitted to be given pursuant to this Guaranty (hereinafter in this paragraph
referred to as "Notice") must be in writing and shall be deemed to have been
properly given or served by personal delivery or by sending same by overnight
courier or by depositing the same in the United States mail, postpaid and
registered or certified, return receipt requested, at the addresses set forth
below.  Each Notice shall be effective upon being delivered personally or upon
being sent by overnight courier or upon being deposited in the United States
Mail as aforesaid.  The time period in which a response to any such Notice
must be given or any action taken with respect thereto, however, shall
commence to run from the date of receipt if personally delivered or sent by
overnight courier or, if so deposited in the United States Mail, the earlier
of three (3) Business Days following such deposit and the date of receipt as
disclosed on the return receipt.  Rejection or other refusal to accept or the
inability to deliver because of changed address of which no Notice was given
shall be deemed to be receipt of the Notice sent.  By giving at least fifteen
(15) days prior Notice thereof, Guarantor or Lender shall have the right from
time to time and at any time during the term of this Guaranty to change their
respective addresses and each shall have the right to specify as its address
any other address within the United States of America.  For the purposes of
this Guaranty:

The address of Lender is:

The First National Bank of Boston
100 Federal Street
Boston, Massachusetts 02110
Attn:  Real Estate Division



<PAGE>


with a copy to:

The First National Bank of Boston
115 Perimeter Center Place, N.E.
Suite 500
Atlanta, Georgia 30346
Attn:  Jeffrey L. Warwick

and to:

Bank of America Illinois
231 South LaSalle Street
15th Floor
Chicago, Illinois  60697
Attn: Andy Hensel

and a copy to each other Lender which may now or hereafter become a party to
the Credit Agreement at such address as may be designated by such Lender.

The address of Guarantor is:

Storage Trust Realty
2407 Rangeline
Columbia, Missouri  65202
Attn:  Stephen M. Dulle

     15.   Governing Law.  GUARANTOR ACKNOWLEDGES AND AGREES THAT THIS
GUARANTY AND THE OBLIGATIONS OF GUARANTOR HEREUNDER SHALL BE GOVERNED BY AND
INTERPRETED AND DETERMINED IN ACCORDANCE WITH THE LAWS OF THE COMMONWEALTH OF
MASSACHUSETTS (EXCLUDING THE LAWS APPLICABLE TO CONFLICTS OR CHOICE OF LAW).

    16.   CONSENT TO JURISDICTION; WAIVERS.  GUARANTOR HEREBY IRREVOCABLY
AND UNCONDITIONALLY (A) SUBMITS TO PERSONAL JURISDICTION IN THE COMMONWEALTH
OF MASSACHUSETTS OVER ANY SUIT, ACTION OR PROCEEDING ARISING OUT OF OR
RELATING TO THIS GUARANTY, AND (B) WAIVES ANY AND ALL PERSONAL RIGHTS UNDER
THE LAWS OF ANY STATE (I) TO THE RIGHT, IF ANY, TO TRIAL BY JURY, (II) TO
OBJECT TO JURISDICTION WITHIN THE COMMONWEALTH OF MASSACHUSETTS OR VENUE IN
ANY PARTICULAR FORUM WITHIN THE COMMONWEALTH OF MASSACHUSETTS, AND (III) TO
THE RIGHT, IF ANY, TO CLAIM OR RECOVER ANY SPECIAL, EXEMPLARY, PUNITIVE OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES OTHER THAN ACTUAL
DAMAGES.  GUARANTOR AGREES THAT, IN ADDITION TO ANY METHODS OF SERVICE OF
PROCESS PROVIDED FOR UNDER APPLICABLE LAW, ALL SERVICE OF PROCESS IN ANY SUCH
SUIT, ACTION OR PROCEEDING MAY BE MADE BY CERTIFIED OR REGISTERED MAIL, RETURN
RECEIPT REQUESTED, DIRECTED TO GUARANTOR AT THE ADDRESS SET FORTH IN PARAGRAPH
14 ABOVE, AND SERVICE SO MADE SHALL BE COMPLETE FIVE (5) DAYS AFTER THE SAME
SHALL BE SO MAILED.  NOTHING CONTAINED HEREIN, HOWEVER, SHALL PREVENT LENDER
FROM BRINGING ANY SUIT, ACTION OR PROCEEDING OR EXERCISING ANY RIGHTS AGAINST
ANY SECURITY AND AGAINST GUARANTOR PERSONALLY, AND AGAINST ANY PROPERTY OF
GUARANTOR, WITHIN ANY OTHER STATE.  INITIATING SUCH SUIT, ACTION OR PROCEEDING
OR TAKING SUCH ACTION IN ANY STATE SHALL IN NO EVENT CONSTITUTE A WAIVER OF
THE AGREEMENT CONTAINED HEREIN THAT THE LAWS OF THE COMMONWEALTH OF
MASSACHUSETTS SHALL GOVERN THE RIGHTS AND OBLIGATIONS OF GUARANTOR AND LENDER


<PAGE>

HEREUNDER OR OF THE SUBMISSION HEREIN MADE BY GUARANTOR TO PERSONAL
JURISDICTION WITHIN THE COMMONWEALTH OF MASSACHUSETTS.  GUARANTOR HEREBY
WAIVES ANY OBJECTION THAT IT MAY NOW OR HEREAFTER HAVE TO THE VENUE OF ANY
SUCH SUIT OR ANY SUCH COURT OR THAT SUCH SUIT IS BROUGHT IN AN INCONVENIENT
COURT.  GUARANTOR CERTIFIES THAT NO REPRESENTATIVE, AGENT OR ATTORNEY OF ANY
LENDER HAS REPRESENTED, EXPRESSLY OR OTHERWISE, THAT SUCH LENDER WOULD NOT, IN
THE EVENT OF LITIGATION, SEEK TO ENFORCE THEIR FOREGOING WAIVERS AND
ACKNOWLEDGES THAT LENDER HAS BEEN INDUCED TO ENTER INTO THIS GUARANTY AND THE
OTHER LOAN DOCUMENTS TO WHICH THEY ARE PARTIES BY, AMONG OTHER THINGS, THE
WAIVERS AND CERTIFICATIONS CONTAINED IN THIS PARAGRAPH 16.  GUARANTOR
ACKNOWLEDGES THAT IT HAS HAD AN OPPORTUNITY TO REVIEW THIS PARAGRAPH 16 WITH
ITS LEGAL COUNSEL AND THAT GUARANTOR AGREES TO THE FOREGOING AS ITS FREE,
KNOWING AND VOLUNTARY ACT.

     17.   Successors and Assigns.  The provisions of this Guaranty shall be
binding upon Guarantor and its heirs, successors, successors in title, legal
representatives, and assigns, and shall inure to the benefit of Lender, its
successors, successors in title, legal representatives and assigns.

     18.   Assignment by Lender.  This Guaranty is assignable by Lender in
whole or in part in conjunction with any assignment of the Note or portions
thereof, and any assignment hereof or any transfer or assignment of the Note
or portions thereof by Lender shall operate to vest in any such assignee the
rights and powers, in whole or in part, as appropriate, herein conferred upon
and granted to Lender.

     19.   Severability.  If any term or provision of this Guaranty shall be
determined to be illegal or unenforceable, all other terms and provisions
hereof shall nevertheless remain effective and shall be enforced to the
fullest extent permitted by law.

    20.   Disclosure.  Guarantor agrees that in addition to disclosures made
in accordance with standard banking practices, any Lender may disclose
information obtained by such Lender pursuant to this Guaranty to assignees or
participants and potential assignees or participants hereunder.

    21.   No Unwritten Agreements.  THIS GUARANTY REPRESENTS THE FINAL
AGREEMENT BETWEEN THE PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF
PRIOR, CONTEMPORANEOUS OR SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES.  THERE
ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN THE PARTIES.

    22.   Time of the Essence.  Time is of the essence with respect to each
and every covenant, agreement and obligation of Guarantor under this Guaranty.

    23.   Ratification.  Guarantor does hereby restate, reaffirm and ratify
each and every warranty and representation regarding Guarantor or its
Subsidiaries set forth in the Credit Agreement as if the same were more fully
set forth herein.

    24.   Limitation on Liability.  NO OBLIGATION OR LIABILITY WHATSOEVER OF
THE GUARANTOR (WHETHER  AS GUARANTOR OR AS GENERAL PARTNER OF THE BORROWER)
WHICH MAY ARISE AT ANY TIME UNDER THIS GUARANTY OR ANY OBLIGATION OR LIABILITY

<PAGE>

WHICH MAY BE INCURRED BY IT PURSUANT TO ANY OTHER LOAN DOCUMENT SHALL BE
PERSONALLY BINDING UPON, NOR SHALL RESORT FOR THE ENFORCEMENT THEREOF BE HAD
TO, THE PRIVATE PROPERTY OF ANY OF THE GUARANTOR'S SHAREHOLDERS, TRUSTEES,
OFFICERS OR EMPLOYEES, REGARDLESS OF WHETHER SUCH OBLIGATION OR LIABILITY IS
IN THE NATURE OF CONTRACT, TORT OR OTHERWISE.  NOTHING HEREIN SHALL DIMINISH
OR IMPAIR THE RIGHTS OF AGENT AND THE BANKS TO PURSUE ANY REMEDY AGAINST ANY
ASSETS OF THE GUARANTOR.


<PAGE>

     IN WITNESS WHEREOF, Guarantor has executed this Guaranty under seal on
the 25th day of January, 1996.

                                        STORAGE TRUST REALTY,
                                        a Maryland real estate investment trust


                                        By:______________________________
                                        Name:_________________________
                                        Title:__________________________


                                                            [SEAL]