Contract documents

When reviewing the contract documents, flip through every page of the drawings and read the specification. If you do not understand something, ask and learn. Many times small misunderstandings turn into major conflicts as the project moves forward and expectations are not met.

Is the architectural concrete specifically called out on the documents? This is a must; without a clear understanding of where architectural concrete is located, it is difficult to bid. This sometimes includes concrete referenced by the requirements of ACI 301, Specifications for Structural Concrete Section 5.3.3.3 As-cast finishes, which defines three levels of finish. The highest level is Surface finish-3.0 (SF-3.0), which specifies the following:

• Patch voids larger than 3/4 in. wide or 1/2 in. deep;
• Remove projections larger than 1/8 in.;
• Patch tie holes;
• Surface tolerance Class A as specified in ACI 117; and
• Provide mockup of concrete surface appearance and texture.

This to me is the lowest level of architectural concrete and it’s easy to underestimate how difficult even this is to achieve, of course, depending on the owner’s interpretation and expectation.

Although various descriptions, interpretations, and methods exist to achieve an as-cast concrete surface, no unified definitions of different concrete surfaces exist. However, a new guide, ACI 347.3R-13 Guide to Formed Concrete Surfaces, defines several quality levels of formed concrete surfaces and provides methods to achieve and evaluate them. These quality levels are identified by three surface finish categories: 1) Overall formed concrete surface category (CSC); 2) Description of visible effects such as texture, color uniformity, surface irregularities, and construction and facing joints; and 3) Form facing category, that also defines the after-casting allowable surface-void ratio (SVR). All are related to ACI 347-04, Section 3.4 – Irregularities in form surfaces; Classes A, B, C, and D with which the concrete construction industry is familiar. Class A often is used as an architectural finish classification with little other definition. The new guide will help the contractor produce as-cast concrete surfaces that meet the project specifications and expectations while providing a more objective platform to evaluate the work.

Proposal and qualifications

For private work, and occasionally public work, the proposal is the last opportunity to make your bid and state your case on the project. If all else has failed, you can communicate your concerns in the proposal. You don’t want to be saying to the higher bidders later that they were the lucky ones since they didn’t get the job!

If the concrete contractor does everything right and pulls the forms and the results don’t meet the owner’s expectations, what next? I recommend allocating money for tear out in the bid proposal. If no tear-out is deemed necessary then this money is 100% returnable to the owner. This is what I call the “owner’s skin in the game.” It’s easy for the owner to tell the concrete contractor, “I don’t accept it; tear it out” when there’s no cost to the owner. But if the owner has skin in the game, it will cost him something to replace work he considers marginal but that meets the specification. If the work is clearly underperformed, that’s a different story—the concrete contractor clearly owns its unsatisfactory work, but fairness and cooperation are important. For this allocation, 1% to 1.5% of the total concrete cost or 15% of the architectural concrete portion are common numbers to use.

Dan Dorfmueller is president of the D.P. Dorfmueller Co. and consults on architectural concrete for concrete contractors around the world.