1. CONSTRUCTION BLUEPRINT READING
ALPHABET OF LINES

2. CONSTRUCTION BLUEPRINT READING
Drawings contain many types of drafting lines.
The basic straight line as seen in this slide can be emphasized by the weight of the line, these lines are called object lines.

3. CONSTRUCTION BLUEPRINT READING
Object lines are used to show the shape of an object and all visible edges are represented with object lines.
To specify the meaning of each type of line, contrasting lines can be made by varying the width of the lines or breaking the lines in a uniform way.

4. CONSTRUCTION BLUEPRINT READING
Unfortunately there is still a lot of variation on how lines are used.
You will need to check the legend for an explanation on how the object lines are used.
THIS BIRD’S EYE VIEW IS DRAWN WITH MOSTLY OBJECT LINES

5. CONSTRUCTION BLUEPRINT READING
The light full line is used for section lines and building backgrounds.
The medium full line is used for lettering, symbols and circuit lines.
The heavy full line is used for borders around title blocks, schedules and some symbols.
The extra heavy full line is used for the border line to establish the drawing area.

6. CONSTRUCTION BLUEPRINT READING
The importance of recognizing how lines are used, especially solid lines is the difference between block walls and sheet rock walls or a fire wall as opposed to a regular wall.
As a technician determining cable pathways you will need to know what type of wall you will be penetrating and what additional material and tools it will require.

7. CONSTRUCTION BLUEPRINT READING
The lines below are fairly consistent from one architectural firm to another, obviously the solid lines are also used by all architects however the way they weight them and how they’re applied on the drawings may vary slightly.

8. CONSTRUCTION BLUEPRINT READING
The long break line is used for long breaks.
The hidden line shows the edges of objects that are not visible in a particular view.
The match line is used to show the position of the cutting pane, it is used on drawings of large structures to show where one drawing stops and the next drawing starts.

9. CONSTRUCTION BLUEPRINT READING
Dimension lines vary considerably from one set of blue prints to another, however all dimension lines will have a number associated with them to indicate footages.
DIMENSION LINES

10. CONSTRUCTION BLUEPRINT READING
Three more lines that are regularly used are the center line, the property line and the secondary line.
The property line is very similar to the match line however the property line is usually a lighter weight line.

11. CONSTRUCTION BLUEPRINT READING
The center line indicates the center of objects such as holes, pillars or fixtures.
The property line indicates land boundaries on the site plan.
The secondary line is used to outline pieces of equipment or to indicate reference points that are secondary to the drawing’s purpose.

12. CONSTRUCTION BLUEPRINT READING
In this drawing the blue dashed line is the hidden line indicating the concrete footing, dimensions are shown and are displayed on the outside of the drawing and center lines are used in conjunction with the symbol

13. CONSTRUCTION BLUEPRINT READING
In this floor plan the right side is missing and a break line is present.
LONG BREAK LINE

14. CONSTRUCTION BLUEPRINT READING
Some others lines that are used but haven’t been noted are the extension line and the leader line.
EXTENSION LINES ARE USED WITH DIMENSION LINES.
LEADER LINES TIE A GENERAL NOTE TO A SPECIFIC AREA ON THE PRINT OR MAY BE USED TO SHOW WHERE A DIMENSION BEGINS. 3

15. CONSTRUCTION BLUEPRINT READING
Along with all of the different lines there are blueprint symbols that you need to be familiar with.
These symbols are call outs;
Section cuts/details
General notes
Clouds

16. CONSTRUCTION BLUEPRINT READING
The section cuts or details are noted on the prints to direct you to another set of drawings.
One of two symbols are used (they both mean the same thing), in this case the one with the triangle indicates a detail drawing on page E-11, drawing number 5.

17. CONSTRUCTION BLUEPRINT READING
Grounding busbar details;

18. CONSTRUCTION BLUEPRINT READING
Here is an example of a stair detail;

19. CONSTRUCTION BLUEPRINT READING
Detail drawings may show you how to set up the TC with the specific placement of the plywood and racks,.

20. CONSTRUCTION BLUEPRINT READING
General notes are present on the drawings your working with and there can be as many as twelve or more notes on one page.
THE CLOUD IS PREFACED WITH A 1 IN A TRIANGLE AND THE KEYED NOTES ARE CIRCLES WITH NUMBERS

21. CONSTRUCTION BLUEPRINT READING
General notes provide additional information that can not be represented on the drawings.
Some examples are conduit sizes, pull box sizes, mounting heights etc., sometimes they will use the abbreviation typ (typical) which means do the same thing you’ve been doing throughout the project.

22. CONSTRUCTION BLUEPRINT READING
Pay close attention to the clouds as they are a change or special condition that is not typical, there will usually be a general note associated with the cloud.