What are packing shims for?
Packing shims compensate for height differences with millimetre accuracy and transfer loads evenly into the substrate. They are placed between the component and its support, e.g. under thresholds, joists, posts, substructures, brackets or window frames. Because they are made of plastic, they do not absorb moisture, do not rot and remain dimensionally stable over the long term.
Several shims can be combined to achieve the desired total thickness. A small assortment is therefore enough to reach almost any height.
The colour code: thickness at a glance
With GV packing shims, the colour indicates the thickness. On site, you can pick the right shim without measuring, and in an assortment bag it is immediately clear what goes where. Important: the colour code applies per format. For example, a blue shim is 2 mm thick in 60 × 40 mm, but 5 mm thick in 70 × 70 mm. The overview below shows all combinations:
| Thickness | 60 × 40 | 70 × 70 | 100 × 60 | 120 × 50 | 160 × 50 | 180 × 60 | 300 × 80* | JK 80 × 50** |
|---|---|---|---|---|---|---|---|---|
| 1.5 mm | white | – | – | – | – | – | – | – |
| 2 mm | blue | red | blue | red | red | blue | blue | red |
| 3 mm | red | green | red | green | green | red | red | green |
| 4 mm | yellow | yellow | – | – | – | – | yellow | – |
| 5 mm | green | blue | green | blue | blue | green | green | blue |
| 6 mm | – | brown | – | – | – | – | black | – |
| 7 mm | – | – | – | – | – | – | – | brown |
| 10 mm | brown | white | brown | black | black | brown | grey | black |
| 15 mm | grey | black | grey | grey | grey | grey | – | yellow |
| 20 mm | black | black | – | – | – | black | – | black |
* Breakable packing shims (variable length) 300 × 80 mm · ** Adjusting blocks 80 × 50 mm. Formats 120 × 50 and 160 × 50 mm: new version. In the previous version, which is being phased out, the 15 mm shim is yellow instead of grey.
Which format for what?
| Format | Thicknesses | Typical use |
|---|---|---|
| 60 × 40 mm | 1.5 to 20 mm | The smallest format: window construction, interior fit-out, small supports |
| 70 × 70 mm | 2 to 20 mm | Square, with a central hole for fixing |
| 100 × 60 mm | 2 to 15 mm | Medium format for wider supports |
| 120 × 50 mm | 2 to 15 mm | Long format, e.g. timber construction and substructures |
| 160 × 50 mm | 2 to 15 mm | Extra long for continuous supports |
| 180 × 60 mm | 2 to 20 mm | Large format for wide, long supports |
| 300 × 80 mm variable | 2 to 10 mm | Breaks to the required length |
| Adjusting blocks 80 × 50 mm | 2 to 20 mm | With studs, stackable, e.g. photovoltaics and construction |
Rule of thumb: the bearing surface of the shim should be at least as large as the bearing area of the component, so that the load is distributed evenly. The 160 × 50 or 180 × 60 mm formats are suitable for long, continuous supports, and the breakable 300 × 80 mm shims for variable lengths.
Combining thicknesses correctly
- Coarse first, then fine: Start with the thick shims for the basic height, then use thin shims (1.5 to 3 mm) to reach the final dimension.
- Fewer layers are better than many: One 10 mm shim is more stable than five 2 mm shims. Build up large heights with the thick shims.
- Stack flush: Lay the shims exactly on top of each other so that the load is transferred vertically.
- Fixing: Formats with a hole (e.g. 70 × 70 mm) can be screwed in place. Adjusting blocks have studs that interlock when stacked and disappear under pressure.
Load capacity
Compression tests are available for all formats. You can find the test reports as PDFs on the packing shims product page. For high or permanent loads, please observe the requirements of the structural design or the system manufacturer.
Frequently asked questions
Which colour stands for which thickness?
That depends on the format. For 60 × 40 mm, for example: white 1.5 mm, blue 2 mm, red 3 mm, yellow 4 mm, green 5 mm, brown 10 mm, grey 15 mm, black 20 mm. The complete overview for all formats is in the table above.
Can packing shims be stacked?
Yes. Several shims can be combined to achieve the desired thickness. For large heights, use a few thick shims rather than many thin ones, and stack the shims flush.
Are packing shims available in variable lengths?
Yes, the breakable packing shims (variable length) 300 × 80 mm can be broken to the required length. They are available in six thicknesses from 2 to 10 mm.
What are GV packing shims made of?
Made of plastic, manufactured in Germany. Some products contain fibres from sunflower seed husks, which replace up to 35 % of petroleum-based plastic.
These notes are general guidance from practice. The applicable regulations, the specifications of the window or system manufacturers and the project-specific planning are authoritative.