What’s The Best Way To Interpret Shop Drawings And Compare Them To What’s Happening In The Field?

How to Use Shop Drawings to Check Work in the Field

What’s the best way to interpret shop drawings and compare them to what’s actually happening in the field? That’s a great question—and it came from one of the viewers. In this blog, we’ll break down how you can effectively understand and use shop drawings for field checks, and share a few key safety tips to keep in mind.

Understanding the Construction Documents:

Let’s start with the basics. You’ve got:

• Construction Drawings – the paper version of your building, showing what you’re supposed to build.
• Specifications – the technical details that often accompany the drawings.
• Shop Drawings & Submittals – what trade partners submit for review before installation.

Key Reminder: The contract drawings and specifications are your main source of truth. Shop drawings and submittals come after that in the order of precedence, as usually described in Division 1 of your spec book.

So, when there’s a conflict, always go with the contract documents. Inspectors will too.

Real-World Example:

In a previous job under OSHPD (California’s Office of Statewide Health Planning and Development), shop drawings showed clips at 3 ft on center—but the contract drawings said 4 ft. Even though the shop drawings were technically better, OSHPD required the 4 ft spacing because the contract docs ruled.

Moral of the story: Shop drawings are helpful—but only if they align with the contract drawings.

How to Read Shop Drawings:

Every trade, every vendor does them differently. That’s just how it is. So, if you’re confused, you’re not alone. Don’t assume it’s your fault.

Best Approach? Ask the foreman. Seriously.

“What does this symbol mean?”

“How do I read this sheet?”

“Can you walk me through it?”

Most foremen are more than happy to help. They’ve had to call and ask too—so don’t be afraid to speak up and learn the language of each shop drawing set.

Using Shop Drawings in the Field:

Once you’ve reviewed the shop drawings and highlighted what to check:

1. Go to the field.
2. Take the drawings and a foreman with you if possible.
3. Check key components and ask questions.

This isn’t about catching mistakes—it’s about collaborating with trusted trade partners. You’re both on the same team.

A good field check includes:

• Key install components.
• Correct product types.
• Proper assemblies.
• Right materials.

And again, always double-check with the contract documents. If you only use shop drawings—and those have errors—you risk replicating mistakes.

When to Use Shop Drawings:

Use them to:

• Confirm material types.
• Verify product assemblies.
• Inventory delivered equipment.

But for compliance, final inspections, and third-party checks, the contract documents are king.

Final Advice:

Don’t leave shop drawings unchecked and assume they’re always correct. Always verify critical details. When in doubt—go back to the specs and contract drawings.