CLC Blueprint Reading & Technical Specifications 3 — Questions and Answers
Question 1: What does a bold triangle symbol with a number inside it on a detail drawing reference?
- A spot elevation
- A detail reference pointing to an enlarged drawing on another sheet (Correct answer)
- A structural column grid intersection
- A material tag for specification lookup
Correct answer: A detail reference pointing to an enlarged drawing on another sheet
A detail reference triangle contains the detail number and sheet number, directing the reader to an enlarged view of that condition.
Question 2: A specification calls for lumber to be 'S4S.' What does this mean?
- Seasoned 4 ways to standard moisture content
- Surfaced on 4 sides (Correct answer)
- Grade 4, select structural
- Stacked 4 courses high before installation
Correct answer: Surfaced on 4 sides
S4S means the lumber has been surfaced (planed smooth) on all four sides, producing consistent, clean dimensions.
Question 3: On architectural drawings, what does the abbreviation 'CLG HT' refer to?
- Clearance Height
- Ceiling Height (Correct answer)
- Column Grid Height
- Caulk Line Gap Height
Correct answer: Ceiling Height
'CLG HT' is standard shorthand for Ceiling Height, indicating the vertical distance from finished floor to finished ceiling.
Question 4: Which drawing in a construction set typically shows stair tread depth, riser height, and total run?
- Roof framing plan
- Stair section or stair detail (Correct answer)
- Reflected ceiling plan
- Foundation plan
Correct answer: Stair section or stair detail
A stair section or dedicated stair detail provides the vertical and horizontal layout including tread, riser, and total run dimensions.
Question 5: What is the meaning of 'UNO' as used in construction specification notes?
- Unless Noted Otherwise (Correct answer)
- Uniform Nail Offset
- Under Normal Operations
- Ungraded or Not Ordered
Correct answer: Unless Noted Otherwise
'UNO' stands for Unless Noted Otherwise, meaning the stated condition applies everywhere except where a specific exception is called out.
Question 6: A reflected ceiling plan (RCP) shows the ceiling as if:
- Viewed from above with the roof removed
- A mirror placed on the floor reflects the ceiling upward (Correct answer)
- The ceiling is tilted 45° for clarity
- The room is photographed from outside
Correct answer: A mirror placed on the floor reflects the ceiling upward
An RCP uses the convention of a mirror on the floor reflecting upward, so left-right orientation matches the floor plan below it.
Question 7: On a window schedule, the column labeled 'R.O.' most likely refers to:
- Rough Opening (Correct answer)
- Return Opening
- Rated Opening
- Reveal Offset
Correct answer: Rough Opening
R.O. stands for Rough Opening, which is the framed opening size required to receive the window unit including clearance for shimming.
CLC Blueprint Reading & Technical Specifications 3
What does a bold triangle symbol with a number inside it on a detail drawing reference?