Question: How Close is Too Close?
Have you ever had someone or something encroach on your personal space so badly that you wanted to scream “Back Off!”? So how close is too close?
When my daughters were in high school, they went to a school that had a “Six Inch Rule”. Boys and girls had a 6” rule of separation. Now, as most of you fathers of daughters know, six inches is simply not enough!
A distance that can be critical for a masonry contractor is the distance from which masonry should be viewed to determine its acceptability. If we have reached the point of trying to view the masonry from a certain distance, we already have a problem. ASTM C90 Section 7 is titled “Finish & Appearance of Concrete Masonry Units”. Paragraph 7.2 says and I quote, “Where units are to be used in exposed wall construction, the face or faces that are to be exposed shall not show chips or cracks, not otherwise permitted in 7.1.2 and 7.1.3, or other imperfections when viewed from a distance of not less than 20 ft. (6.1m)under diffused lighting”.
So, there it is folks, the magic 20’-0” rule. We have been using it for years to get everyone to back away from the wall. But let me tell you a little secret, ASTM C90 is a manufacturing standard and should only be used to verify if the CMU meets the standard. Paragraph 7.1.2 and 7.1.3 set the tolerances for chips and cracks. I do not recall ever seeing a viewing distance listed in any project specification.
Now what do we do? First, we must understand the term “workmanship.” Webster defines it as “the art or skill of a workman” and also as “the quality imparted to a thing in the process of making.” Workmanship is not a single thing or item, but a combination of several items. In your standard project specifications, you won’t find workmanship as a spec. section. You will find in your typical Division 04 Masonry Specifications in Part 1, a section called “Quality Assurance,” which will describe the process to be used to assure the design team and owner that they are getting what they have requested.
In Part 3 there is a section called “Construction Tolerances.” This section gives dimensional variations allowed in the construction of a masonry wall. These specifications can be bought as a package or developed by the architectural firm. In either instance the spec writer must select items that fit the project. Don’t misunderstand. An architect or engineer can design and specify anything they want as long as it is not less than what is required by the building code. These specifications MUST be read before bidding a project, in case changes in process or cost must be made to accommodate the plans or specifications.
Remember, there is no ASTM standard for workmanship! Everything that would be included in a discussion of the factors involved in the term workmanship may be more than can be put into an ASTM standard. The same people that want to view the masonry at arms-length would probably complain about seeing brush strokes by Michelangelo on the Sistine Chapel ceiling!
Folks, masonry really is an art form! It is made up of individual units put together with hand and eye coordination. Don’t let anyone get close enough to rub their hands or noses on your masonry. Make them back up and enjoy the beauty of masonry as a whole object, and not a single unit.
So, how do we do that you ask? Come back next month and we will discuss what we as masons and contractors can do to get a fair determination of what is acceptable or not.
Until then, “Raise the line and come on around the corner.”