Drawing Vs. Specifications (Why spec govern

Q: Our isometrics show 1/2" DCW/DHW distribution lines. Government QA issued a CDR for deficient pipe size per the specifications—how can that be wrong if the drawings show 1/2"?

A: Because on federal work, drawings don’t “win” a conflict. The contract does.

If the Division 22 specification requires a different size than what an isometric depicts, the specification governs. That’s the point of FAR 52.236-21 (Specifications and Drawings for Construction): when documents disagree, you don’t pick the one you like—you follow the hierarchy.

This CDR didn’t happen because of one bad decision. It happened because several basic controls failed.

What went wrong

1) CQC didn’t reconcile drawings to specs

This should have been resolved before install. The CQC’s job isn’t to confirm what the drawings “look like.” It’s to confirm what the contract requires.

2) The USACE 3-Phase QC process didn’t do its job

This is exactly what the Preparatory and Initial phases are supposed to prevent:

• Preparatory: review the DFOW, confirm governing spec requirements, confirm approved submittals align, resolve conflicts before work starts.

• Initial: verify the first install is compliant—pipe size is one of the easiest checks in the world.

3) Submittal “approval” was treated like a shield

Division 01 language (commonly 01 33 00) is clear: Government acceptance of submittals is not a complete check and does not relieve the contractor of compliance, dimensions, details, or errors.

4) Contractor inspection controls weren’t effective

Whether you cite Division 01 or inspection clauses like FAR 52.246-1, the standard is the same: the contractor has to maintain an inspection system that catches this. Pipe size is not a subtle defect.

How to prevent this next time

• Start with Division 01 (especially submittals and QC requirements), 01 45 00 Quality Control in particular , then go to Division 22.

• Teach your team one sentence from FAR 52.236-21: when there’s a discrepancy, the specs govern.

• Make the Preparatory meeting a real contract-compliance review, not a paperwork event.

• During Initial, physically verify the first install against spec requirements—don’t assume the drawing is “close enough.”

Bottom line

This wasn’t really a piping problem. It was a contract-document hierarchy and CQC execution problem.

On federal work, the safest rule is simple: Drawings illustrate. Specifications govern.