How to read structural steel drawings?

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The essentials for reading steel structural construction drawings


The construction drawing must be read before the structural drawing, thereby establishing the outline of the building. During the reading of the structural drawing, the representation of the same part of the structure and it is shown in the drawing should be checked repeatedly, so that the content of the drawing can be understood accurately.


Reading structural construction drawings is also a gradual process from shallow to deep, from coarse to fine. Structural construction drawings use thick lines to indicate key content to be highlighted. In order to make the drawings clear, codes are often used to represent the components.

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Here’s a list of guidance on how to read structural drawings primarily:





  1. Getting to know the scale of the drawings:


To know the scale of the drawings means to understand how large or small certain items are in your structural project. Most of the scale have dimensions in inches per foot and they are used for small creation. For large creations, other scales may be used. So, the first step to knowing structural drawings is to identify the scale type. If this is not clarified in the structural drawings clearly, consult the structural engineer for proper guidance.


2. Identifying basic symbols of the drawings:


The use of symbols is a very common concept in a structural drawing. The engineers use these symbols to identify various construction items. Also, these symbols follow certain standards which are preset. These symbols are used by structural engineers to identify sections, elevations, and other details. Commonly used symbols are circles, rectangles, and triangles. However, there are several other symbols in a drawing. Understanding the very basic symbols can be of a great help to comprehend the drawings. One can consult a structural engineer to identify basic symbols and their meanings.


3. Identifying the circled numbers:


Structural drawings are drawn on a scale so small that it is impossible to mention each and every detail on a single page. Hence, details are mentioned separately for these drawings. One must look out for circled numbers. These circled numbers indicate that the area circled has its details mentioned on another page. One must look out for these numbers and compare it to the other page where the details are mentioned.


4. Looking for abbreviations:


Like symbols, abbreviations are also common in structural drawings. These abbreviations are used to determine shapes, processes, and even dimensions of the components. While it is not necessary to understand each and every abbreviation, few common abbreviations must be identified for getting greater insight into the project. Some common abbreviation examples are DP which stands for depth and DIA for diameter


5. Consulting a professional:


In case if all the above-mentioned steps fail to guide you through the project, consulting a professional is a great idea. Those who regularly deal with such drawings will provide effective guidance to understand the structural drawings. These individuals can clarify the concepts clearly that one does not understand. It is better to take guidance during early stages of the project so as to avoid any mistakes arising due to improper reading in future.


6. Learn How Scale Works

The scale is a ratio on the sheet that translates to the actual dimension of the building. Thus, every unit of measurement on the drawing translates to something bigger in real life.


The scale tells you how large or small certain structures in the building will be. Generally, most people use inches per foot in determining the dimension of the scales they use. However, this is used mostly for small buildings. Steel Fabrication Melbourne




7. Learn the Meaning of Symbols

You will find tons of symbols in the average structural steel drawing. This is because engineers are familiar and comfortable with numbers and symbols. Hence, infusing it into their drawings is simply a way for them to utilize their knowledge.

Furthermore, symbols save time. This is especially if they have to be repeated several times within the same work. For instance, the symbol that stands for sections or elevations could be used multiple times. Thus, inserting it, as opposed to writing the full word, saves both time and stress.


Popular symbols include circles, rectangles, triangles, etc.


8. Identify Callout Symbols

This is a special type of symbol that deserves specific mention.


Callout symbols draw your attention to other parts of the drawing. They are icons, and you’ll find them sometimes on the margins of the drawing.


When they draw your attention to specific parts of the drawing, it is to give more information regarding the construction. For instance, you can use a callout symbol to indicate where two steel materials should meet.


9. Look Out for Circled Numbers

This is also something curious you may find in a structural steel drawing. There is, however, a simple explanation as to why engineers circle numbers in their drawings.


Circled numbers flag the information on the page in question. It merely informs you that there are further details discussed in a separate part of the drawing. The scales used in drawing are usually so small that details cannot be explained within the pages of the drawing. Hence, it makes sense for any detailed explanation to be done somewhere different. A circled number draws your attention to this.


When you see a circled number, you ought to follow it to the exact page with the details.


10. Identify Abbreviations

Abbreviations are almost as abundant as symbols in structural steel drawings. Engineers use abbreviations much for the same reasons they use symbols, too.


It might be impossible to learn all the abbreviations and what they mean. However, you can learn the common ones. When you run into unfamiliar ones, you could consult an engineer for guidance (that is, if you aren’t one yourself).