What is a gravel hatch?

A gravel hatch is an irregular scatter of short marks representing loose aggregate such as hardcore, ballast or drainage gravel in a section.

How do I import a gravel PAT file into AutoCAD?

Save the .PAT file into a support file search path, run HATCH, choose Custom and select the gravel pattern with the hatch scale at 1.

Can I use this gravel hatch in Revit?

Yes. Import it under Manage, Additional Settings, Fill Patterns with an import scale of 1 and apply it to the aggregate layer of your floor or roof assembly.

Can I change the aggregate density?

Yes. The pattern size controls how coarse the scatter reads. Larger values suit thick hardcore layers, smaller values suit thin ballast or blinding layers.

Gravel Hatch Generator

Create an irregular aggregate pattern for hardcore, ballast and gravel beds.

Free

Material library

Choose a common building material as a starting point.

Gravel loaded. Adjust any parameter below.

Pattern parameters

These values are written into the PAT file.

Pattern name

Generated automatically from the pattern type and dimensions.

Units

Pattern size

Module of the material symbol. Scales the whole hatch.

Rotation

deg

Scale

Multiplies every exported distance in the PAT definition.

Live preview

720 mm wide

PAT definition

gravel_120.pat

;; Generated with ArchSupply Utilities - Hatch Pattern Generator;; Drawing units: millimetres (metric pattern);; Load in AutoCAD with HATCH > Custom, or in Revit via Manage > Additional Settings > Fill Patterns.*GRAVEL_120, Gravel: loose graded aggregate, 120 mm module18, 0,6, 60,120, 36, -84128, 36,52.8, 60,126, 31.2, -94.874, 79.2,21.6, 72,114, 28.8, -85.2161.446971, 5.588312,93.927379, 35.52,96, 18.977989, -77.022011154.56005, 31.917694,73.288243, 35.52,96, 15.725882, -80.274118112.107806, 29.053938,36.345378, 35.52,96, 12.526198, -83.47380226.661113, 9.891783,22.399503, 35.52,96, 16.243417, -79.75658338.781295, 53.698489,14.317587, 22.2,60, 9.064906, -50.93509438.425457, 58.862555,26.105863, 22.2,60, 6.139318, -53.860682112.200178, 33.328585,14.338661, 22.2,60, 7.243922, -52.756078

PAT definition ready

PAT output is in beta. Verify the pattern scale after importing into your CAD or BIM application.

About the gravel hatch

Gravel, hardcore and ballast are drawn as loose irregular aggregate rather than an ordered pattern. The randomness is the point: it signals a granular layer that has been laid and compacted, not a solid material.

The pattern is common in ground floor build ups, drainage details, roof ballast layers and external hard landscaping sections, usually sandwiched between a membrane and a slab.

The aggregate distribution is deterministic, so the same parameters always produce the same PAT file and drawings stay consistent across a project. Adjust the pattern size and export for AutoCAD or Revit.

How to use the PAT file

Download the .PAT file, or copy the definition into your own pattern library file.
AutoCAD: place the file in a support path, then choose Hatch, Pattern type Custom and pick the pattern name.
Revit: Manage, Additional Settings, Fill Patterns, New, Custom, then import the .PAT file and set the import scale.
Metric patterns assume millimetre drawing units; imperial patterns assume inches.

Frequently asked questions

What is a gravel hatch?: A gravel hatch is an irregular scatter of short marks representing loose aggregate such as hardcore, ballast or drainage gravel in a section.
How do I import a gravel PAT file into AutoCAD?: Save the .PAT file into a support file search path, run HATCH, choose Custom and select the gravel pattern with the hatch scale at 1.
Can I use this gravel hatch in Revit?: Yes. Import it under Manage, Additional Settings, Fill Patterns with an import scale of 1 and apply it to the aggregate layer of your floor or roof assembly.
Can I change the aggregate density?: Yes. The pattern size controls how coarse the scatter reads. Larger values suit thick hardcore layers, smaller values suit thin ballast or blinding layers.

Related materials

Every material opens the same generator with its pattern preloaded.