What line width where?
September 19, 2020 3 Comments
What line width (or weight), do I use where, when structural drafting? In CAD, what color should I draw my structural elements. What line definitions suit what application? Below is a basic list which provide answers to these questions.
This article should be read in conjunction with the article: Standard colors and line weights in CAD.
| Drawing Location | Application | Weight | Color | Linetype |
| Grid | Grid lines | 0.18mm | Magenta | Center |
| Footing Plan | Proposed footings | 0.5mm | Red | Continuous |
| Slab Plans | Outlines | 0.5mm | Red | Continuous |
| Slab Plans | Wall under | 0.18mm | Magenta | Hidden |
| Slab Plans | Slab underside | 0.35 | Yellow | Hidden |
| Slab Plans | Reinforcement | 0.7mm | Green | Continuous |
| Slab Plans | Control Joint | 0.35mm | Yellow | Dashed Dot |
| Slab Plans | Isolation or Construction Joint | 0.7mm | Green | Dashed Dot |
| Steel Framing | Bracing | 0.35mm | Yellow | Dashed Dot |
| Steel Framing | Purlins | 0.25mm | White | Continuous |
| Steel Framing | Main Steel members | 0.7mm | Green | Continuous |
| Steel Framing | Secondary Steel members | 0.35mm | Yellow | Continuous |
| Details | Concrete outlines | 0.5mm | Red | Continuous |
| Details | Reinforcing bars | 0.35mm | Yellow | Continuous |
| Details | Reinforcing mesh | 0.25mm | White | Hidden |
| Details | Steelwork outline | 0.35mm | Yellow | Continuous |
| Details | Steelwork hidden | 0.25mm | White | Hidden |
| Details | Masonry | 0.25mm | White | Continuous |
| Details | Masonry hidden | 0.18mm | Magenta | Hidden |
| Details | Indicative architectural items | 0.18mm | Grey | Continuous |
| Details | Waterproofing Membranes | 0.25mm | White | Hidden |
| Details | Timber | 0.25mm | White | Continuous |
Architectural Paper Sizes
North America has a special series of paper sizes defined for architectural purposes. In general these have aspect ratios of 4:3 or 3:2 which are similar to the aspect ratio of computer screens. Sizes are used for technical drawings in Structural Engineering, Mechanical Engineering, HVAC Engineering, Hydraulic Engineering, Electrical Engineering, Plumbing Drawings, Shop Detailing and Architectural Drafting etc.
The following table gives details of the sizes for architectural paper.
| Size | Width x Height (mm) | Width x Height (in) | Aspect Ratio |
| Arch A | 229 x 305 mm | 9.0 x 12.0 in | 4:3 |
| Arch B | 305 x 457 mm | 12.0 x 18.0 in | 3:2 |
| Arch C | 457 x 610 mm | 18.0 x 24.0 in | 4:3 |
| Arch D | 610 x 914 mm | 24.0 x 36.0 in | 3:2 |
| Arch E | 914 x 1219 mm | 36.0 x 48.0 in | 4:3 |
| Arch E1 | 762 x 1067 mm | 30.0 x 42.0 in | 7:5 |