Technical Specifications, Standards and Construction Tolerances

The specifications are part of the contract documents that define the qualitative requirements of the project to be constructed. The dictionary defines specification as “a detailed description of requirements, dimensions, materials, etc., as of a proposed building, machine, bridge, etc.,” and further as “the act of making specific.” The role of the drawings is to define the geometry of a project, including dimensions, form, and details. The specifications are intended to complement this by defining the nature of the materials that are to be used and the description of the workmanship and procedures to be followed in constructing the project.

Generally, most specifications can be divided into three main elements, or parts:

  1. Bidding and Contractual Documents and Forms (incl. Instruction to Bidders)
  2. Conditions of the Contract (General Conditions & Special Conditions)
  3. Technical Specifications

Part III of the specifications refers to that portion of the specifications that a layperson usually thinks of when one speaks of specifications. In this portion of the document are the detailed technical provisions that relate to the installation or construction of the various parts of the work and to the materials used in the work. There are several ways of logically dividing these sections into subject areas so as to lend some sort of order to the final document.

CSI Master Specifications Format

In recent years, an organization called the Construction Specifications Institute (CSI) tackled the task of attempting to inject some degree of uniformity and standardization into the general arrangement and method of writing construction specifications. To this end it has been enormously successful. It has provided an organizational structure for prescriptive and performance-based specifications, product information, technical data, and cost data. It created order where none existed before by setting forth a list of standardized “divisions” that are supposed to work for everything, and with a little imagination can indeed be adapted to most construction projects.

As regards the technical specifications of the construction project, master format specifications are included in the contract documents. The master format is a master list of section titles and numbers for organizing information about construction requirements, products, and activities into a standard sequence. It is a uniform system for organizing information in project manuals, for organizing cost data, for filling product information and other technical data, for identifying drawing objects, and for presenting construction market data. MasterFormat™ (1995 edition) consisted of 16 divisions; however, MasterFormat (2004 edition) consists of 48 divisions (49 is reserved). MasterFormat contract documents produced jointly by the Construction Specifications Institute (CSI) and Construction Specifications Canada (CSC) are widely accepted as standard practice for preparation of contract documents.

The CSI has moved slowly from its original element (buildings) to its current 50-Division Format. The new Master Format is intended to be flexible to dynamic changes that may occur in the construction industry. It better addresses heavy civil construction, process engineering construction, industrial construction, sustainable design, security, and life safety. Life-cycle features such as commissioning, operating, and maintaining have also been incorporated into the new format. For software packages such as CAD, BIM, code checking, cost estimating, scheduling, and so on to be interoperable, some standard numbering system will be used and the 50-Division Format is most likely going to be that numbering system.

CSI Three-Part Technical Section Format

One of the most valuable contributions of the CSI to the work of the contractor and the inspector is the adoption of the three-part technical section format (Figure 6.4). It is a time-honored concept first observed by the author on the published specifications standards for a Federal Aid Road Act project dated in 1917. Under this arrangement each technical section is divided into three parts, each containing one type of information only. With this system, fewer items are overlooked simply because the specifications for a particular product were sandwiched between some unlikely paragraphs dealing with the installation of some totally unrelated item—which just happened to be located there because some architect or engineer happened to think of it while writing that portion of the section.

In the three-part technical section format, all technical sections of the specification are divided into three distinct parts, always in the same order: (1) general, (2) products, and (3) execution. Each Part is further organized into a system of articles and paragraphs. If followed faithfully, as most users of the system will do, it makes the reading of the specifications a simple, orderly process and eliminates many an error due to oversight.

Section No.

Title

Part 1- General

1.01—General Reference/Related Sections

1.02—Description of Work

1.03—Related Work specified elsewhere in other sections

1.04—Submittals

1.05—Delivery, Handling, and Storage

1.06—Spare Parts

1.07—Warranties

In addition to the foregoing, a reference is made for items such as preparation of mock-up, quality control plan, and any other specific requirements related to the product or system specified herein.

Part 2- Product

2.01 — Materials

2.02 — Description of Work

Part 3- Execution

2.01 — Installation

2.02 — Site Quality Control

standard is a level of quality or achievement, especially a level that is thought to be acceptable. It is something that you use in order to judge the quality of something else.

A standard is simply a definition of how something should be. Per Pyzdek (1999):

Standards are documents used to define acceptable conditions or behaviors and to provide a base line for assuring that conditions or behaviors meet the acceptable criteria. In most cases standards define minimum criteria; world class quality is, by definition, beyond the standard level of performance. Standards can be written or unwritten, voluntary or mandatory. Unwritten quality standards are generally not acceptable. (p. 2)

Standards are used to ensure that a product, system, or service measures up to its specifications and is safe for use. Standards are the key to any conformity assessment activity.

There are many organizations that produce standards; some of the best known organizations in the quality field are:

  1. International Organization for Standardization (ISO)
  2. American Society for Quality (ASQ)
  3. American National Standards Institute (ANSI)
  4. American Society for Testing and Materials (ASTM)
  5. National Fire Protection Association (NFPA)
  6. British Standards Institution (BSI)
  7. American Concrete Institute (ACI)
  8. Institute of Electrical and Electronics Engineers (IEEE)

Standards produced by these organizations/institutes are recognized worldwide. These standards are referred in the contract documents by the designers to specify products or systems or services to be used in a project. They are also used to specify the installation method to be followed or the fabrication works to be performed during the construction process.

Tolerances in construction are generally a variation in dimension, construction limit, or physical characteristic of a material. They are a practical variation related to the function of the material or finished work and commonly accepted standards of the construction industry. Tolerance is the range of acceptable results.  If a result is out of tolerance, it must be rejected.

One of the factors that should be considered in the efforts to involve the specifications writer and the inspector in an effective working relationship is the inclusion in the specifications of tolerance limits, instead of the traditional methods of specifying absolutes. Some problems for which the inspectors have been blamed can actually be traced to the fact that the specifications either provided for no tolerance at all, or provided tolerances that were either unreasonable or unenforceable. An excellent example of properly specified tolerances can be seen in the American Concrete Institute Standard Specifications for Tolerances for Concrete Construction and Materials (ACI 117-90 and Commentary (117R-90).

Where tolerances are specified, the inspector can be more secure in taking a stand with a contractor on an issue. The specifying of tolerances further eliminates many disputes with contractors who otherwise felt that rejections for nonconformance based upon the inspector’s interpretation of absolute values was too subjective. As an absolute value is impossible to obtain consistently, an even greater burden is placed upon the inspector who is obligated to administer such a contract, for the inspector is then always being placed in the position of deciding “how close is close enough?”