Concrete specifications should provide clear, enforceable requirements that are easily interpreted the same way by the owner, construction manager, design professional, inspector and concrete contractor. The ideal specification uses measurable qualities that define acceptance criteria. It’s not enough to ensure that the specification can be understood; just as importantly, the specification must be written so it can’t be misunderstood. That requires the specifier to carefully select words that convey exact meanings.
Unfortunately, that isn’t always done. So when reading a specification or drawing notes, it’s wise to highlight portions that can cause problems, then discuss them as soon as possible. Based on examples of specifications from the American Concrete Institute, AIA MasterSpec, the U.S. Department of Veterans Affairs and conversations with members of the American Society of Concrete Contractors, here’s a sampling of troublesome words, phrases or sentences.
Absolutely: As in: “Surface must be absolutely smooth to receive floor covering where called for on the drawings.” No finished or formed surface is absolutely smooth, flat, true or plumb. Specified tolerances are used to designate acceptable variations from the ideal condition.
Any: This is another ambiguous word in many situations. The synonym for “any” is “some.” But is that what the specifier wanted in this requirement: “Any voids greater than ½ inch shall be filled.” This requirement says that some voids greater than ½ inch, but not necessarily all of them, must be found and filled.
Compare this with the ACI 301-10 in its requirement for an SF-2.0 finish: “Patch voids larger than 34-inch wide or 12-inch deep.”
The ACI wording leaves no doubt that all voids falling within the ranges mentioned must be patched, and the terse language is clear and concise.
Coordinate: As in: “Coordinate the work of other trades who will provide items (such as anchor bolts, pipe bollards, sleeves, piping and conduit) to be cast in the concrete.” Some specifiers believe that sentences of this kind include coordination of tolerances with those of other trades. When tolerances of other trades are tighter than common concrete construction tolerances, such as those in ACI 117-10, coordination is not the job of the concrete contractor. Coordination of this type is the job of the design professional.
Excessive: This is another word that is too vague to convey an exact meaning, and thus can be enforced in an arbitrary manner. “Protect exposed surfaces of concrete from ... excessively hot or cold temperatures.” This requirement can be easily fixed by stating the temperatures considered to be excessive.
Immediately: Immediately can be interpreted to mean “without delay,” but what is a delay? For instance, if “... for flat slab/plate, reshoring is required immediately after stripping operations are complete....” Immediately implies “instantly, without lapse of time, or without delay.” That makes this requirement vulnerable to the “impossibility of performance” defense because there is a lapse of time between stripping and reshoring. One author of a Guide to Specification Writing writes about this in terms of whether or not the specifications are doable. “Specifications that are not doable are not really specifications; they’re science fiction”. 1
Minimum: This word in the specifications is likely to cause disputes and delays because it implies there is no minus tolerance on the property being specified. For instance, some specifications give minimum values for compressive strength. This can be interpreted to mean that no strength test can fall below the value specified. In fact, ACI 318-11, Building Code Requirements for Structural Concrete, allows tests up to 500 psi below the specified strength as long as the average of all sets of three consecutive tests don’t fall below the specified strength.
Minimum also implies there is no tolerance on numerical value as in the statement that: “Minimum contraction joint depth, using a conventional saw, hand tools or inserts, shall be 14 of the pavement thickness.” However, Section 4.9.1 of ACI 117-10, Specification for Tolerances for Concrete Construction and Materials, allows a tolerance of 14 inch for sawcut joint depth. So for a 6-inch-thick pavement, is the allowable sawcut depth 112 inch or 114 inch?
Slowly: As in: “Place concrete for columns slowly and in one operation between joints.” The word slowly gives no indication of the desired placing rate. A maximum placing rate in feet per unit of time is preferred.
Uniform: This word and its variants appear in many specifications, but it is not a measurable property. Consider the following: “Vibrate concrete to produce thorough compaction, complete embedment of reinforcement and concrete of uniform and maximum density without segregation of mix.”
Use of the word uniform isn’t the only problem here. We can also ask what constitutes “thorough compaction” and “maximum density.” For architectural concrete, the same specification instructs the contractor to build a mock-up and: “Treat the finished front surface of the mock-up to produce a uniform appearance similar in every respect to the approved sample area.” Adding the qualifying requirement that the mock-up appearance be similar in every respect to the approved sample area only adds to the contractor’s difficulty in understanding the owner’s expectations.
Two other examples from a different specification point out other problems: “Deliver concrete of uniform slump and proportions” and “Place concrete in uniform horizontal layers not more than 36 inches high for consolidation.” Specifying a slump range is much superior to requiring “uniform slump,” and the meaning of “uniform horizontal layers” is unclear.
Because uniformity is not a measurable property, contractors have no idea what degree of uniformity will be required on a given project. Decisions on specification compliance are subjective, making it difficult to estimate the cost of uniformity expectations.
When these words and phrases are found in specifications, it’s best to clarify their meanings prior to construction and preferably before bidding. But if disputes do arise later in the project cycle, contractors do have a weapon if their interpretations are reasonable. A judge, jury or arbitrator may rule that a contractor’s interpretation prevails. 1
When your project goes bad and enters into litigation, one of the most likely steps your lawyers will take is examine the specifications in a search for errors and inconsistencies they can claim mislead you and caused a loss. Very few specifications are totally free from such defects, and the party responsible for the losses is then the party who drafted the defective specifications. Such responsibility is a fundamental principle of law. 1
In today’s economic climate, few contractors can afford to lose dollars due to a loss that resulted from their interpreting the specifications reasonably. That’s why it’s wise to do a word search that detects dangerous words and clarify meanings as soon as possible in the construction cycle.