It is acceptable to change the chair height to assist with the construction of tilt-up panels as long as the reinforcement still meets the specified concrete cover.

• A. True
• B. Only with supervisor approval
• C. Not specified
• D. False

Answer: (D)

The main idea here is that reinforcement placement and concrete cover are determined by the design drawings and must be kept exactly as specified. The chairs are used to hold the bars at their intended height and position during the pour, ensuring the required concrete cover and proper spacing from other elements.

Changing chair height to help with construction would alter the vertical position of the bars. Even if the final cover appears to meet the specification, modifying chair height changes a critical detail that is part of the engineer’s design. Such changes aren’t allowed in the field unless the drawings are revised and the change is approved by the engineer (and the appropriate documentation updated). Field adjustments to reinforcing placement require proper modification rather than ad-hoc changes.

So, this statement is not acceptable because reinforcement placement must follow the approved design, not be adjusted on the fly to “still meet” the cover. If there’s a difficulty with chair height, the correct step is to obtain engineering-approved revisions or use the specified method in the drawings.