Chapter 45 Structural Drafting

Introduction This chapter introduces basic concepts and drawing methods Expected of an entry-level drafter in an architect’s or engineer’s office Refer to the text for a project example Main objectives: to coordinate various plans and to draw coordinated details that correspond to different areas of the building

Plan the Drawing Plan views for similarities Start with the floor plan Get a general understanding of the structure Move to upper level and work to lowest Shows loads that must be supported as work progresses (e.g., beams of roof supported by columns, pedestals on slab plan, and footings at foundation)

Plan the Drawing (cont’d.) As you work on various plans, study details that relate to the plan Gives a better understanding Should result in faster drawing production

Procedure–From Calculations to Working Drawings Mathematical solutions to particular problems Printed following related problem Drafter is given a set of specifications and is expected to determine the goal of the engineer Then translates results into working drawings Typically means skipping over math work

Procedure–From Calculations to Working Drawings (cont’d.) Sketches Provided by an engineer Tools to help solve calculations Drafter uses them as a guide to determine size and material to be used

Procedure–From Calculations to Working Drawings (cont’d.) Drafter is expected to study similar jobs and details for common elements Common notes Common connection methods Also expected to consult vendors’ catalogs for specific details of prefabricated material

Procedure–From Calculations to Working Drawings (cont’d.) Drawing layout methods Group all plan views together Then all roof details, all concrete details, and so on, in the same order of plan views Group a plan view with all related details Show roof plan and then roof details Show slab plan and then slab details

Procedure–From Calculations to Working Drawings (cont’d.) Methods of assembling a project Drafters in architectural and structural firms typically work with CADD Well-suited to CADD drafting because of layering possibilities Develop a base drawing Use external referencing to bind material to base drawing

Procedure–From Calculations to Working Drawings (cont’d.) Refer to the text for a list of common commercial layer names including: Civil drawing layer names Architectural layer names Structural layers

Procedure–From Calculations to Working Drawings (cont’d.) Annotation Important factors to considered before placing text: Who will use the drawing Information the text is to define Scale factor of the text

Procedure–From Calculations to Working Drawings (cont’d.) Annotation (cont’d.) Text placement Location of text relative to drawing and within drawing file Text orientation should be parallel to bottom or parallel to right edge of the page Text is generally placed within inches of the object Much of the text used can be standardized and placed in a template drawing

Procedure–From Calculations to Working Drawings (cont’d.) Annotation (cont’d.) Text placement (cont’d.) On details, text can be placed within the detail if large open spaces are part of the drawing It is preferable to keep text out of the drawing Text should be aligned to enhance clarity Text should be placed on a layer with a major group code of ANNO

Procedure–From Calculations to Working Drawings (cont’d.) Annotation (cont’d.) Types of text Title General notes (e.g., project, discipline, sheet, reference keynotes) Simplified keynotes Local notes

Procedure–From Calculations to Working Drawings (cont’d.) Managing drawings at multiple scales Drawing sheets can be assembled for plotting using layouts and viewports Each time you enter a layout, you’re working with a floating viewport Allows you to look through the paper and see the drawing in model space Displays drawing in layout for plotting

Procedure–From Calculations to Working Drawings (cont’d.) Detail coordination As you draw each detail, provide room for: Title Scale Detail marker under detail

Order of Precedence Text project (refer to the text): Includes sketches and engineer’s calculations Has some very large errors Helps you to learn to think as a drafter If you find an error, do not make changes until you have discussed them with the engineer (instructor)

Order of Precedence (cont’d.) Follow this order of precedence: Written changes by engineer (instructor) as change orders Verbal changes given by engineer (instructor) Engineer’s calculations Information written in goals, project, and method is more reliable than sketches

Order of Precedence (cont’d.) Follow this order of precedence (cont’d.): Sketches by the engineer (text) Lecture notes and sketches Your own decision Should it come to this, check with your instructor