"Exposed to public view," "exposed to view," "prominently exposed to public view" and "permanently exposed to view" are common phrases used in specifications for structural concrete. Typically, appearance requirements are more rigorous for any of these categories. Use of the word "public" seems to cause the most problems. We've heard specifers and general contractors claim that concrete for interior prison walls, the inside of a cooling tower, the above-water portion of a sewage treatment tank, and an isolated stairwell are all exposed to public view. This in turn often requires a Class A surface, filling bugholes, color-matched patching of honeycomb and other rework, with costs borne by the concrete contractor.

Is public view defined?

ACI 301-10, "Specifications for Structural Concrete," includes the following definition:

exposed to view — portion of structure that can be observed by the public during normal use.

ACI Concrete Terminology, found at www.concrete.org contains the following two definitions:

concrete, exposed — concrete surfaces formed so as to yield an acceptable texture and finish for permanent exposure to view. (See also concrete, architectural.)

concrete, architectural — concrete that will be permanently exposed to view and therefore requires special care in selection of the concrete materials, forming, placing and finishing to obtain the desired architectural appearance.

Note that neither of the ACI Concrete Terminology definitions uses the word "public," but that several other ACI documents do.

An ACI 301-10 Mandatory Checklist item for Section 4.8.3, Form Offsets, tells the specifier to "Designate class of surface (A, B, C, D), with Class A: For surfaces prominently exposed to public view where appearance is of special importance;"

In ACI 347-04, "Guide to Formwork for Concrete," Section 3.2, "Class A is suggested for surfaces prominently exposed to public view where appearance is of special importance."

Definition of public is the key

The ACI definitions skirt the issue of what constitutes public view. And that's where disputes originate when a construction team member claims certain concrete is exposed to public view. If we search for definitions of a "public place," two definitions offer some help:

"A public place is generally an indoor or outdoor area, whether privately or publicly owned, to which the public have access by right or by invitation, expressed or implied, whether by payment of money or not, ... (www.USLegal.com)

"(usually prenominal) maintained at the expense of, serving, or for the use of a community: a public library." (www.dictionary.com)

Based on these definitions, it's hard to defend the position that the aforementioned walls of a prison cell, sewage treatment plant, stairwell or the inside of walls in a cooling tower are in any sense exposed to public view. How many times is the public invited to view the inside of a cooling tower?

A common sense approach

Section R4.8.3 of the Commentary for ACI 117-06, "Specifications for Tolerances for Concrete Construction and Materials and Commentary," expressed the intent of this phrase quite well:

Specifiers should anticipate local irregularities in formed surfaces. The purpose of establishing different classes of surface is to define the magnitude of irregularities in a manner that is consistent with the exposure of the concrete when in service. As stated in Section R4.4.3, the term "exposed to view" is primarily an aesthetic consideration and this tolerance is properly applied to conditions that are readily apparent to the public in normal use of the structure. [emphasis added].

Within a commercial structure, for example, the inside face of a concrete exit stair or the face of a concrete wall in an area, such as a mechanical or electrical room, would not be considered exposed to view.

Use care when bidding

Ask the specifier to note which sections of any structure will be exposed to public view. Get it in writing. Then read the appearance requirements for such sections and the repairs that may be required. It's the concrete contractors' right to know what they are agreeing to.