Look at any good foundation section. Before you read a single word, you already know where the earth is, where the PCC bed is, where the RCC footing is and where the brick wall starts. That is the job of an AutoCAD hatch.
Bad hatching does the opposite. Patterns that print as solid black blobs, dots so tiny they vanish, or a hatch that refuses to fill because “the boundary is not closed”. Every beginner hits all three.
This is Lesson 4 of our free AutoCAD for Civil Engineers series. You will learn which pattern to use for each material, how to get the scale right the first time, and how to fix the errors that waste hours.
Series: AutoCAD for Civil Engineers · View full course →
You are on Lesson 4 of 6.
Previous: Lesson 3: Dimension & Text Styles
Next up: Lesson 5: Blocks & Attributes
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What Hatching Does in a Civil Drawing
A hatch is a pattern that fills a closed area. In civil and building drawings it tells the reader three things:
- What material is there (concrete, brick, earth, sand, stone).
- What is cut in a section (hatched) versus what is seen beyond (not hatched).
- What is new versus existing (for example, existing walls in light hatch, new walls in dark).
Simple rule: In a section, hatch only what the cutting plane passes through. Things you see beyond the cut are drawn as lines, not hatched.
Material Hatch Patterns for Civil Drawings
These are the patterns most Indian design offices use. Always check your company or client standard first, and keep a legend on the drawing.
| Material | AutoCAD pattern | Notes |
|---|---|---|
| Natural earth / soil | EARTH | Used below foundations and for cut sections of ground |
| Filled earth / backfill | EARTH (lighter) or DOTS | Keep it visually lighter than natural ground |
| PCC (plain cement concrete) | AR-CONC | Dots and triangles = concrete |
| RCC (reinforced concrete) | AR-CONC + ANSI31 | Concrete pattern with 45° lines on top, a very common Indian convention |
| Brick masonry (section) | ANSI31 | 45° lines |
| Brick masonry (elevation) | AR-BRSTD | Shows real brick courses |
| Block work (AAC / concrete block) | AR-B816 or ANSI32 | Keep different from brick |
| Sand / plaster / screed | AR-SAND | Fine dots |
| Stone soling / rubble | GRAVEL | Irregular stones |
| Waterproofing / membrane | SOLID (thin) | Thin band |
| Columns in floor plans (1:100) | SOLID | Makes the structure stand out |
| Glass (section) | No hatch or ANSI37 | Usually just two thin lines |
Useful trick: For RCC, draw two hatches in the same boundary: AR-CONC first, then ANSI31 on top. Use Separate hatches = No so each one stays a single object.
How to Use AutoCAD Hatch (Step by Step)
- Make layer G-HATCH current (from Lesson 1).
- Type H and press Enter. The Hatch Creation ribbon tab opens.
- In Pattern, pick the material pattern (for example EARTH).
- Set Scale and Angle (see the scale section below).
- Click Pick Points and click inside the closed area. AutoCAD finds the boundary.
- Press Enter to finish.
Pick Points vs Select Boundary Objects
| Method | When to use |
|---|---|
| Pick Points (click inside) | Most of the time. Fast, finds the boundary automatically |
| Select (pick objects) | When the area is one closed polyline or circle, or when Pick Points finds the wrong boundary in a crowded drawing |
Hatch Scale: The Part Everyone Gets Wrong
The same hatch scale can look perfect at 1:50 and print as a black blob at 1:100. You need to understand two types of patterns.
1. ANSI and ISO patterns (ANSI31, ANSI32, ANSI37…)
These are defined by their spacing on paper. ANSI31 lines are 3.175 mm apart at scale 1.
So the rule is the same as text in Lesson 3:
Hatch scale = drawing scale
| Drawing scale | ANSI31 scale | Spacing on paper |
|---|---|---|
| 1:20 | 20 | 3.2 mm |
| 1:50 | 50 | 3.2 mm |
| 1:100 | 100 | 3.2 mm |
2. AR- patterns (AR-CONC, AR-SAND, AR-BRSTD…)
The “AR” patterns are architectural, real-world size patterns. AR-BRSTD bricks are drawn at the size of a real brick. So these start near scale 1 and you adjust by eye.
| Pattern | Starting scale (drawing in mm) | Adjust if |
|---|---|---|
| AR-BRSTD | ~1.13 for Indian 230 × 75 mm brick courses | Courses don’t match your brick size |
| AR-CONC | 1 at 1:50, 2 at 1:100 | Dots print as grey fog (go bigger) |
| AR-SAND | 1 at 1:50, 2 at 1:100 | Prints as solid grey (go bigger) |
| EARTH | about half the drawing scale (25 at 1:50, 50 at 1:100) | Lines too close |
Quick tip: Don’t trust the screen. Hatch a 1 m × 1 m test square, open Plot Preview, and look at it at real paper size. Then adjust the scale once and write it down. You only need to do this once per pattern.
Set Your Defaults Once
These system variables save you from picking the same settings every time:
| Variable | Set to | What it does |
|---|---|---|
| HPLAYER | G-HATCH | Every new hatch goes on G-HATCH automatically, whatever layer is current |
| HPSCALE | 100 | Default hatch scale for your usual 1:100 work |
| HPASSOC | 1 | Hatch updates when you stretch the boundary |
| HPGAPTOL | 0 (raise only if needed) | Allows hatching across tiny gaps |
Type the variable name at the command line, then the value.
Hatch Settings That Make Drawings Professional
Associative hatch
Keep Associative on. When you stretch a wall or move a footing edge, the hatch follows. If you erase the boundary, the hatch loses its link, so keep boundaries on a layer you don’t delete.
Draw order (hatch behind lines)
A hatch drawn over your wall lines hides them. Set Draw Order: Send to Back in the ribbon, or run HATCHTOBACK once to push every hatch behind everything else.
Hatch origin (for brick and tiles)
For AR-BRSTD or tile patterns, use Set Origin and pick the bottom-left corner of the wall. The bricks now start with a full course at the corner instead of a random cut.
Transparency and colour
Set hatches to a light grey colour or 50% transparency so they support the drawing without overpowering lines and dimensions. With a plot style (CTB), make the G-HATCH colour plot thin.
Annotative hatch
Like annotative dimensions, an annotative hatch resizes for each viewport scale. We will use this in Lesson 6 when we plot from layouts.
Editing Hatches
| Task | How |
|---|---|
| Change pattern, scale or angle | Click the hatch; the Hatch Editor ribbon opens. Or type HE |
| Copy hatch settings to another area | MA (MATCHPROP), pick the source hatch, then click the target hatch |
| Hatch with the same settings as an existing one | In HATCH, use Match Properties |
| Recreate a lost boundary | Select the hatch, then Recreate Boundary in the Hatch Editor |
| Split one hatch into separate objects | Hatch Editor → Separate Hatches |
Common Hatch Problems and Fixes
| Problem | Cause | Fix |
|---|---|---|
| “A closed boundary cannot be determined” | Small gap in the lines | Zoom to the red circles AutoCAD shows; close the gap with OSNAP Endpoint (Lesson 2). Or raise HPGAPTOL slightly |
| Hatch fills the whole building | Boundary leaks somewhere | Same as above, or draw a closed polyline with BO (BOUNDARY) and use Select |
| Hatch prints as solid black | Scale too small | Increase scale (see the scale tables) |
| Hatch is invisible / looks empty | Scale far too big | Decrease scale |
| “Hatch spacing too dense” error | Scale tiny for a huge area | Increase scale |
| Hatch covers wall lines | Draw order | HATCHTOBACK |
| Drawing became very slow | Many dense hatches, or SOLID on huge areas | Increase scale, freeze G-HATCH while drafting |
| Hatch doesn’t follow the stretched wall | Not associative | Hatch Editor → Associative on, or recreate |
| Hatch on wrong layer | HPLAYER not set | Set HPLAYER = G-HATCH; move existing ones with Properties |
Beginner trap: Never explode a hatch. It turns into thousands of tiny lines, the file gets huge and you can never edit the pattern again.
10-Minute Practice Exercise: Isolated Footing Section
Draw a simple footing section (all sizes in mm):
- Ground line across the whole drawing. Excavation 1500 deep.
- PCC bed: 1500 wide × 150 thick at the bottom of the excavation.
- RCC footing: 1200 wide × 450 thick on the PCC.
- Column stub: 230 × 230 rising from the footing to plinth.
- Plinth beam / brick wall above: a 230 mm brick wall on top.
Now hatch it:
- Set HPLAYER = G-HATCH and HPSCALE = 50 (we’ll plot this at 1:50).
- EARTH, scale 25, below and beside the excavation.
- AR-CONC, scale 1, for the PCC bed.
- AR-CONC + ANSI31 (scale 50) for the RCC footing and column.
- ANSI31, scale 50, angle 0, for the brick wall. (Turn the angle to 90 if it looks identical to RCC. Many offices draw brick at 45° and RCC lines in the opposite direction.)
- DOTS or a lighter EARTH for the backfill above the footing.
- Run HATCHTOBACK, then dimension it with the TCS-50 style from Lesson 3.
- Add a small legend box showing each hatch with its material name.
Open Plot Preview at 1:50. If you can tell every material apart from arm’s length, you’ve done it right.
Key Takeaways
- Hatching tells the reader what material is cut.
- ANSI patterns: hatch scale = drawing scale. AR- patterns: start near 1 and test.
- Always test with Plot Preview, not the screen.
- Set HPLAYER = G-HATCH once and never think about it again.
- Keep hatches associative, behind lines and in a light colour.
- “Boundary not closed” means a gap. Fix the gap with OSNAP.
- Never explode a hatch, and always add a legend.
AutoCAD Hatch FAQs
Which hatch pattern is used for concrete in AutoCAD?
AR-CONC is the standard concrete pattern. For RCC, many Indian offices draw AR-CONC with ANSI31 diagonal lines on top to show reinforcement.
Which hatch pattern is used for brick in AutoCAD?
ANSI31 (45° lines) is common for brick in section. For elevations, AR-BRSTD shows realistic brick courses.
What hatch scale should I use for a 1:100 drawing?
For ANSI patterns such as ANSI31, use 100. For AR- patterns like AR-CONC and AR-SAND, start around 2 and check in Plot Preview, because they are drawn at real-world size.
Why does AutoCAD say a closed boundary cannot be determined?
Your lines have a gap or don’t meet exactly. AutoCAD shows red circles near the problem. Close it using OSNAP Endpoint, or increase HPGAPTOL slightly for tiny gaps.
How do I send all hatches behind lines?
Type HATCHTOBACK and press Enter. Every hatch in the drawing goes to the back of the draw order.
How do I set a default layer for hatches?
Set the system variable HPLAYER to your hatch layer name, for example G-HATCH. New hatches go there automatically.
What is an associative hatch?
An associative hatch is linked to its boundary. When you move or stretch the boundary, the hatch updates automatically.
Why is my hatch showing as solid black?
The hatch scale is too small, so the lines are too close together. Increase the scale until the pattern is readable in Plot Preview.
Series: AutoCAD for Civil Engineers · View full course →
✅ Lesson 1: AutoCAD Layers Explained
✅ Lesson 2: OSNAP, Ortho & Polar Tracking
✅ Lesson 3: Dimension & Text Styles
📍 Lesson 4: Hatching for Civil Drawings (you are here)
⏭ Lesson 5: Blocks & Attributes: Doors, Grid Bubbles, Title Blocks
⏭ Lesson 6: Layouts, Viewports & Plotting to PDF
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