Blueprint Reading Flashcards

What does the abbreviation 'EL.' or 'ELEV.' indicate on a construction drawing?

Answer: Elevation or height above datum

EL. or ELEV. indicates elevation — the vertical height of a point measured from a reference datum, typically expressed in metres above sea level or above an established benchmark on site.

On a site plan, what do contour lines represent?

Answer: Points of equal elevation on the ground

Contour lines connect points of equal elevation on a site plan, showing the topography and slope of the land. Closely spaced contour lines indicate steep terrain, while widely spaced lines indicate gentle slopes.

What is the purpose of a specifications book (spec book) that accompanies a set of construction drawings?

Answer: To describe material quality, installation methods, and performance requirements not shown on drawings

Specifications complement the drawings by detailing material standards, acceptable products, installation procedures, quality assurance requirements, and performance criteria that cannot be effectively communicated through drawings alone.

What does a centre line symbol (long dash, short dash, long dash pattern) indicate on a blueprint?

Answer: The centre axis of a symmetrical feature, opening, or structural member

The centre line symbol uses an alternating long-dash, short-dash pattern to indicate the centre axis of symmetrical objects such as columns, windows, doors, walls, or circular features.

When reading a roof plan, what does the arrow direction typically indicate?

Answer: The direction of roof slope (downward)

On a roof plan, arrows indicate the direction of the roof slope, pointing downward toward the eaves where water drains. The slope or pitch is typically noted alongside the arrow.

In the CSA standard for construction drawings used in Canada, what sheet designation prefix is used for structural drawings?

Answer: S (Structural)

In Canadian construction drawing standards, structural drawings are prefixed with 'S' (e.g., S-101, S-201). This follows CSA conventions similar to the National CAD Standard for organizing drawing sets.