PRESS RELEASE July 17, 2003

Simpson Manufacturing Co., Inc.
Announces Second Quarter Earnings

    DUBLIN, Calif., July 17  -- Simpson Manufacturing
Co., Inc. (NYSE: SSD) (the "Company") announced today that its 2003 second
quarter net sales increased 18.0% to $146,460,792 as compared to net sales of
$124,150,330 for the second quarter of 2002. Net income increased 18.7% to
$17,681,608 for the second quarter of 2003 as compared to net income of
$14,891,601 for the second quarter of 2002. Diluted net income per common
share was $0.71 for the second quarter of 2003 as compared to $0.60 for the
second quarter of 2002. For the first half of 2003, net sales increased 16.1%
to $262,916,972 as compared to net sales of $226,521,565 for the first half of
2002. Net income increased 16.6% to $28,706,509 for 2003 as compared to net
income of $24,621,541 for 2002. Diluted net income per common share was $1.15
for the first half of 2003 as compared to $0.99 for the first half of 2002.
    In the second quarter of 2003, sales growth occurred throughout North
America and Europe. The growth in the United States was strongest in the
southern and northeastern regions. Simpson Strong-Tie's second quarter sales
increased 19.2% over the same quarter last year, while Simpson Dura-Vent's
sales increased 9.6%. Lumber dealers, homecenters and contractor distributors
were the fastest growing Simpson Strong-Tie connector sales channels. The
sales increase was broad based across most of Simpson Strong-Tie's major
product lines. Simpson Strong-Tie's engineered wood products and seismic and
high wind related products had the highest percentage growth rates in sales.
Sales of Simpson Dura-Vent's Direct-Vent and gas vent products increased
compared to the second quarter of 2002 while sales of its pellet vent and
chimney product lines were flat. The customer that had informed Simpson
Dura-Vent last year that it planned to supply certain venting products from
internal sources is expected to continue buying these products from Simpson
Dura-Vent through the third quarter of 2003. Sales of the affected products to
this customer decreased slightly in the first half of 2003 as compared to the
first half of 2002.
    Income from operations increased 16.6% from $24,795,028 in the second
quarter of 2002 to $28,906,286 in the second quarter of 2003 and gross margins
were unchanged at 41.6%. Selling expenses increased 11.2% from $11,133,905 in
the second quarter of 2002 to $12,383,934 in the second quarter of 2003,
primarily due to increased costs associated with the addition of sales
personnel and advertising and promotional activities. General and
administrative expenses increased 24.8% from $15,711,585 in the second quarter
of 2002 to $19,601,051 in the second quarter of 2003. This increase was
primarily due to increased cash profit sharing, as a result of higher
operating income, higher bad debt expense including the reversal of the
allowance for doubtful accounts in 2002 related to a significant customer. The
increase was also partially due to the recognition of stock option expenses in
accordance with recently adopted accounting standards. The tax rate was 39.1%
in the second quarter of 2003, down from 40.5% in the second quarter of 2002.
The decrease was primarily due to tax credits for research and development and
manufacturing investment related to the expansion of the Company's facilities
in Stockton, California.
    In the first half of 2003, sales growth occurred throughout North America
and Europe. The growth in the United States was strongest in the southern and
western regions. Simpson Strong-Tie's first half sales increased 17.7% over
the same period last year, while Simpson Dura-Vent's sales increased 5.8%.
Lumber dealers, homecenters and contractor distributors were the fastest
growing Simpson Strong-Tie connector sales channels. The sales increase was
broad based across most of Simpson Strong-Tie's major product lines. Simpson
Strong-Tie's engineered wood products and seismic and high wind related
products had the highest percentage growth rates in sales. Sales of Simpson
Dura-Vent's Direct-Vent and gas vent products increased compared to the first
half of 2002 while sales of its pellet vent and chimney product lines
decreased.
    Income from operations increased 15.7% from $40,964,841 in the first half
of 2002 to $47,391,431 in the first half of 2003 and gross margins increased
from 40.1% in the first half of 2002 to 40.5% in the first half of 2003. The
increase in gross margins was primarily due to improved absorption of fixed
overhead costs offset somewhat by increased material costs. Selling expenses
increased 10.4% from $21,663,264 in the first half of 2002 to $23,910,643 in
the first half of 2003, primarily due to increased costs associated with the
addition of sales personnel and advertising and promotional activities.
General and administrative expenses increased 24.8% from $28,205,969 in the
first half of 2002 to $35,199,776 in the first half of 2003. This increase was
primarily due to increased cash profit sharing, as a result of higher
operating income, higher bad debt expense including the reversal of the
allowance for doubtful accounts in 2002 related to a significant customer. The
increase was also partially due to the recognition of stock option expenses in
accordance with recently adopted accounting standards and increased
professional fees.  The tax rate was 39.7% in the first half of 2003, down
from 40.6% in the second half of 2002. The decrease was primarily due to tax
credits for research and development and manufacturing investment related to
the expansion of the Company's facilities in Stockton, California.
    In May 2003, the Company's subsidiary, Simpson Strong-Tie Canada, Limited,
completed the purchase of 100% of the equity of MGA Construction Hardware &
Steel Fabricating Limited and MGA Connectors Limited, both Canadian federal
corporations, for approximately USD $9.8 million in cash. MGA manufactures and
distributes throughout Canada and portions of the United States a quality line
of connectors used in construction. This purchase did not have a material
effect on the Company's results of operations for the three and six months
ended June 30, 2003.
    Investors, analysts and other interested parties are invited to join the
Company's conference call on Friday, July 18, 2003, at 6:00 am, Pacific Time.
To participate, callers may dial 800-362-0571. The call will be webcast
simultaneously as well as being available for approximately one month through
a link on the Company's website at http://www.simpsonmfg.com.
    This document contains forward-looking statements, based on numerous
assumptions and subject to risks and uncertainties. Although the Company
believes that the forward-looking statements are reasonable, it does not and
cannot give any assurance that its beliefs and expectations will prove to be
correct. Many factors could significantly affect the Company's operations and
cause the Company's actual results to be substantially different from the
Company's expectations. Those factors include, but are not limited to:  (i)
general economic and construction business conditions; (ii) customer
acceptance of the Company's products; (iii) materials and manufacturing costs;
(iv) the financial condition of customers, competitors and suppliers; (v)
technological developments; (vi) increased competition; (vii) changes in
capital market conditions; (viii) governmental and business conditions in
countries where the Company's products are manufactured and sold; (ix) changes
in trade regulations; (x) the effect of acquisition activity; (xi) changes in
the Company's plans, strategies, objectives, expectations or intentions; and
(xii) other risks and uncertainties indicated from time to time in the
Company's filings with the Securities and Exchange Commission. Actual results
might differ materially from results suggested by any forward-looking
statements in this report. The Company does not have an obligation to publicly
update any forward-looking statements, whether as a result of the receipt of
new information, the occurrence of future events or otherwise.

    The Company's results of operations for the three and six months ended
June 30, 2003 and 2002, are as follows:

                             Three Months                 Six Months
                             Ended June 30,              Ended June 30,
                             (Unaudited)                 (Unaudited)
                           2003          2002        2003           2002

    Net sales         $146,460,792  $124,150,330 $262,916,972  $226,521,565
    Cost of sales       85,569,521    72,509,812  156,415,122   135,687,491
      Gross profit      60,891,271    51,640,518  106,501,850    90,834,074

    Selling expenses    12,383,934    11,133,905   23,910,643    21,663,264
    General and
     administrative
     expenses           19,601,051    15,711,585   35,199,776    28,205,969

    Income from
     operations         28,906,286    24,795,028   47,391,431    40,964,841

    Interest income, net   106,808       216,405      236,757       474,731
      Income before
       taxes            29,013,094    25,011,433   47,628,188    41,439,572

    Provision for
     income taxes       11,331,486    10,119,832   18,921,679    16,818,031
      Net income       $17,681,608   $14,891,601  $28,706,509   $24,621,541

    Net income per
     share:
      Basic                  $0.72         $0.61        $1.17         $1.01
      Diluted                $0.71         $0.60        $1.15         $0.99

    Weighted average
     shares outstanding:
      Basic             24,604,164    24,465,340   24,592,820    24,417,648
      Diluted           24,957,412    24,809,380   24,936,338    24,763,682

    Other data:
      Depreciation and
       amortization     $4,136,908    $3,588,984   $8,103,361    $7,354,196


    The Company's financial position as of June 30, 2003 and 2002, and
December 31, 2002, is as follows:

                                          June 30,           December 31,
                                        (Unaudited)          (Unaudited)
                                   2003             2002         2002
    Cash and short-term
     investments               $109,908,299     $85,599,578  $121,001,667
    Trade accounts receivable,
     net                         94,699,861      79,749,530    55,313,885
    Inventories                  97,004,974      92,922,483    93,079,620
    Other current assets         11,356,524       9,449,414    10,619,065
      Total current assets      312,969,658     267,721,005   280,014,237

    Property, plant and
     equipment, net             104,461,724      87,155,900    97,396,608
    Other noncurrent assets      28,497,266      19,285,433    18,990,220
      Total assets             $445,928,648    $374,162,338  $396,401,065

    Trade accounts payable      $19,325,007     $19,832,660   $14,217,487
    Notes payable and current
     portion of long-term debt    1,977,686       2,955,105     1,257,782
    Other current liabilities    35,481,182      27,121,094    26,262,216
      Total current liabilities  56,783,875      49,908,859    41,737,485

    Long-term debt                5,313,247       5,442,806     5,479,834
    Stockholders' equity        383,831,526     318,810,673   349,183,746
      Total liabilities and
       stockholders' equity    $445,928,648    $374,162,338  $396,401,065


    Simpson Manufacturing Co., Inc., headquartered in Dublin, California,
through its subsidiary, Simpson Strong-Tie Company Inc., designs, engineers
and is a leading manufacturer of wood-to-wood, wood-to-concrete and
wood-to-masonry connectors and pre-fabricated shearwalls. Simpson Strong-Tie
also offers a full line of adhesives, mechanical anchors and powder actuated
tools for concrete, masonry and steel. The Company's other subsidiary, Simpson
Dura-Vent Company, Inc., designs, engineers and manufactures venting systems
for gas and wood burning appliances. The Company's common stock trades on the
New York Stock Exchange under the symbol "SSD."

    For further information, contact Barclay Simpson at (925) 560-9032.