How to Read Blueprint Books

Blueprints give instructions to builders.

Blueprints are used to describe tools, machinery and other kinds of apparatuses which may be unfamiliar to people who are not in that particular industry, and to guide those who are. Blueprints are also used to show, in detail, construction projects of all types. Well-written blueprints will present a thorough explanation of a process or object through labeled diagrams of whatever the subject is. A blueprint is literally that proverbial "picture worth a thousand words." Blueprints speak their own language of symbols and codes, and if you are to read them, you must learn how they are laid out and their symbol and code language.

Instructions

1. Look for the titles of the pages which make up the blueprint. Arrange the pages of the blueprint by how you want to study that particular tool, machinery or construction project. Pick a starting point and work your way through the pages in sequence, gradually building the total picture.

2. Start with the foundation phase, if you are studying a construction project, since the foundation is the first actual building phase after lot and site preparation. Locate the footings page because digging the footings is the first part of building the foundation.

3. Find the legend of the footings page. Look for it in either of the corners, top and bottom. It is normally labeled as such. Search for it in the other pages, if you do not find it on each page. (Symbol keys may be listed on separate pages of the blueprint by themselves with reference to which page the symbols should be matched to.)

4. 

   The legend defines lines, broken lines and all other symbols on the blueprint.

   Find the first legend symbol and its accompanying meaning. Locate that symbol on the blueprint drawing. Keep looking until you find every time that first symbol appears, and match the locations, descriptions and number of times it appears on the page.

5. Search for the information blocks next. Read the added information these blocks contain. Clarify your mental picture of what is represented by pairing block information, symbols and meanings. Ignore blank information blocks, since that is the draftsman's way of letting you know the information has already been covered or will be later.

6. 

   Blueprints are often adjusted during construction out of necessity.

   Look for and read any revision boxes on the page. Check for the revision letter (A, B, C) and the matching noted explanation of the revision. Use the revised version as the finalized, official version.

7. Study the scale block. Find it normally in the title block of the blueprint. Use it to get a fixed idea of the project's actual size. Do the math for the scale, and you will have the finished dimensions. Study the plan drawing all the while matching the block information, legend symbols and their meanings, until you have formed a complete mental image of the project or object.

Tips & Warnings

• Blueprints are not difficult to master once you learn the symbols and know what you are looking at.

• Ask for help from an available professional if you are not sure about a drawing or symbol. Do not presume to know if you are not sure.

References

• E Plans: How to Read Blueprints
• Construction Classes: Blueprint Reading
• Cad-Design-and-Drafting-Service: How to Read Blueprints

Resources

• Contractor-Books: Blueprint Reading and Construction Blueprint Reading for ...