Download presentation
Presentation is loading. Please wait.
Published byKaren Jenkins Modified over 9 years ago
1
Methods of Specifying ACT 380 1
2
Objective Recognize the language, proper preparation, and appropriate situation for the four methods of specifying. 2
3
4 Methods of Specifying O Descriptive O Performance O Reference Standards O Proprietary *****See pages 5.58 through 5.7 3
4
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
5
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
6
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
7
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
8
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
9
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
10
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
11
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
12
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
13
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
14
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
15
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
16
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
17
Closed Proprietary Spec O Only one product is named O Several products may be named as options O NO substitutions 17
18
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
19
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
20
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
21
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
22
Descriptive 22 2-1/2 INCHES to 3 INCHES DIAMETER MEDIUM RED TO RUST COLOR CAPABLE OF MEETING TRADITIONAL COOKING OR EATING CLASSIFICATIONS
23
Performance 23 TASTES GREAT
24
Reference Standard 24 USA Brand, USDA GRADE # 1
25
Proprietary 25 JONATHAN
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.