methods of specifying
DESCRIPTION
Methods of Specifying. ACT 380. Objective. Recognize the language, proper preparation, and appropriate situation for the four methods of specifying. 4 Methods of Specifying. Descriptive Performance Reference Standards Proprietary *****See pages 5.58 through 5.7. Descriptive. - PowerPoint PPT PresentationTRANSCRIPT
Methods of Specifying
ACT 380
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Objective
Recognize the language, proper preparation, and appropriate situation for the four methods of specifying.
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4 Methods of Specifying
O DescriptiveO PerformanceO Reference StandardsO Proprietary
*****See pages 5.58 through 5.7
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DescriptiveO 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
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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
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5 Steps to Preparing Descriptive Spec
O Research available productsO Research critical features neededO 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.
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PerformanceO Specifies the required resultsO The criteria by which the
performance will be judgedO The method by which all this can be
verifiedO The contractor may choose the
materials and methods as long as it complies with the performance criteria
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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
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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
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Reference Standards
O Requires a product or process be in accordance with an established standardO 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)
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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
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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
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Guidelines for Using Reference Specs
O Know the standardO 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
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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
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Guidelines for Using Reference Specs
O A complete designation includes: name of the issuing organization, number of the standard, title, and date of issueO 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
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Proprietary SpecO 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 open16
Closed Proprietary Spec
O Only one product is namedO Several products may be named as
optionsO NO substitutions
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Open Proprietary SpecO Prices are requested for specified
alternativesO Substitutions and cost adjustments
may be proposed by the biddersO Products are allowed as substitutions
after approval by A/E
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Advantages of Proprietary Spec
O Close control of product selectionO 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
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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
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Simplified Example of Methods of Specifying—
Class ExerciseO 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 DescriptiveO PerformanceO Reference StandardsO Proprietary
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Descriptive
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2-1/2 INCHES to 3 INCHES DIAMETER
MEDIUM RED TO RUST COLOR
CAPABLE OF MEETING TRADITIONAL COOKING OR EATING CLASSIFICATIONS
Performance
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TASTES GREAT
Reference Standard
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USA Brand, USDA
GRADE # 1
Proprietary
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JONATHAN