Methods of
Specifying
ACT 380
1
Objective
Recognize the language, proper preparation,
and appropriate situation for the four
methods of specifying.
2
4 Methods of Specifying
O Descriptive
O Performance
O Reference Standards
O Proprietary
*****See pages 5.58 through 5.7
3
Descriptive
O Defines exact properties of materials and
methods of installation without using
proprietary names
O Is prescriptive – the products and processes
are specified – not the results
O Once widely used – but as projects have
become more complex and better reference
standards are available – used less
4
Example Descriptive Method
O A concrete mix of four-parts coarse
aggregate, two-parts fine aggregate, and
one-part cement with a 0.5 water-cement
ratio is specified
O It is implied that “ a performance strength of
3,000 psi after 28 days” will result in this
mix – but is not specified
O If concrete conforming to this mix were
supplied- but failed - the contractor would
not be held responsible
5
5 Steps to Preparing Descriptive
Spec
O Research available products
O Research critical features needed
O Determine which features are best specified
and which are best shown on the drawings
O Describe critical features (min. acceptable
requirements)
O Provide specific information about
submittals, testing, and other procedures
needed to ensure product meets needs. Be
realistic in doing this.
6
Performance
O Specifies the required results
O The criteria by which the performance will be
judged
O The method by which all this can be verified
O The contractor may choose the materials and
methods as long as it complies with the
performance criteria
7
Problem with Performance
Spec
O If incomplete…it can result in major loss of
control over the quality of materials,
equipment, and workmanship
O Much more time consuming than other
methods of specifying
8
Performance vs. Descriptive
O In a simple project one is requiring the use
of a “ceiling hanger”. Performance
requirements in this case can easily be
incorporated by:
O Performance spec – “non-sag”
AS OPPOSED TO:
O Descriptive spec – “straightened No. 11 wire,
tightly wrapped two times’
O See page 4.43; fig 4.8-A
9
Reference Standards
O Requires a product or process be in accordance
with an established standard
O Typical standards encompass:
O Basic material standards (ASTM C 33-93 standard spec
for concrete aggregates)
O Product standards (ANSI/AAMA 302.9 specs for
aluminum windows)
O Design standards (ACI 318 – building code
requirements for reinforced concrete)
10
Reference Standards con’t
O Workmanship standards (ASTM E 737 standard
practice for installation of storm windows,
replacement….)
O Test method standard (ASTM E 34 chemical
analysis of aluminum and aluminum alloys
O Codes (ANSI/ASME A17.1 safety code for
elevators and escalators
11
Reference Standards con’t
O These are incorporated into the specification
by referring to a number, title, or other
designation
O Realize that standards usually refer to
minimum requirements
12
Guidelines for Using Reference
Specs
O Know the standard
O Some reference standards may contain
provisions. Theses provisions may be voided
in a footnote or subsequent paragraph unless
specifically stated in the specifications
O Some standards include several categories.
i.e., ASTM C 150-89 standard spec for
portland cement actually covers 8 types of
cement. If not stated which one…the least
expensive may be used…may not meet
project requirements
13
Guidelines for Using Reference
Specs
O Incorporate the standard properly –
O Because the reference standards sometimes
refer to workmanship, this could cause
conflicting or duplicate statements with
Conditions of the Contract or Division 1. The
solution: Include a clause in the
Supplementary Conditions stating that the
requirements of the Conditions of the
Contract govern over the requirements of
reference standards
14
Guidelines for Using Reference
Specs
O A complete designation includes: name of
the issuing organization, number of the
standard, title, and date of issue
O Dates can be a concern because periodically
standards are updated Solution: in Divsion1,
Section 014200 – References include a
statement which is similar to this, “the date of the
standard is that in effect as of Bid date, or date of
Owner-Contractor Agreement when there are no
bids”
O Enforce the requirements of the standard
15
Proprietary Spec
O Specifies actual brand names, model
numbers, and other proprietary information
O Prescriptive (descriptive method is other
one)
O Federal and public projects forbid the use of
this method except in a few special
circumstances
O 2 main types: closed and open
16
Closed Proprietary Spec
O Only one product is named
O Several products may be named as options
O NO substitutions
17
Open Proprietary Spec
O Prices are requested for specified
alternatives
O Substitutions and cost adjustments may be
proposed by the bidders
O Products are allowed as substitutions after
approval by A/E
18
Advantages of Proprietary
Spec
O Close control of product selection
O Preparation of more detailed and
complete drawings based on precise
information obtained from
manufacturer’s data
O Shorter specifications and reduced
production time
O Simplification of bidding by narrowing
competition and removing product
pricing as a major variable
19
Disadvantages of Proprietary
Spec
O Elimination of narrowing of competition
O Requiring products with which the contractor
has perhaps had little or bad experience
(slow delivery, lack of proper technical
services, difficult payment arrangements)
O Favoring certain products and
manufacturers over others
20
Simplified Example of Methods of
Specifying— Class Exercise
O For this very simple example we will use a
common fruit --- an APPLE.
O How would you specify an apple using the
following methods?
O Descriptive
O Performance
O Reference Standards
O Proprietary
21
Descriptive
2-1/2 INCHES to 3 INCHES
DIAMETER
MEDIUM RED TO RUST
COLOR
CAPABLE OF MEETING
TRADITIONAL COOKING
OR EATING
CLASSIFICATIONS
22
Performance
TASTES GREAT
23
Reference Standard
USA Brand, USDA
GRADE # 1
24
Proprietary
JONATHAN
25