Blueprint & Isometric Drawing Reading Flashcards

At a scale of 1/8" = 1'-0", a line measures 2-1/2 inches. What length does it represent?

Answer: 20 ft

2.5 ÷ 0.125 = 20 feet.

Using an engineer's scale of 1" = 20', a site utility line measures 3 inches. What is its length?

Answer: 60 ft

3 inches × 20 ft per inch = 60 ft.

A 40-foot building drain is installed at 1/8" per foot slope. What is the total fall?

Answer: 5 inches

40 × 1/8" = 5 inches of fall.

What is the purpose of a north arrow on a site or floor plan?

Answer: Orient the drawing to true or plan north

The north arrow orients the sheet so you can relate it to the site and other drawings.

What is a benchmark or datum on a civil or site drawing?

Answer: A fixed reference elevation used for measuring heights

A benchmark gives a known elevation from which sewer inverts and grades are referenced.

Your drawings show a drain passing through a structural beam. What is the correct action?

Answer: Submit a request for information (RFI) and wait for direction

Conflicts with structure must be resolved by the design team through an RFI, not by field changes.

What are as-built drawings?

Answer: Marked-up records of what was actually installed

As-builts document the final installed locations and any deviations from the design.