One of the recurring topics of interest among our distribution partners is floor remediation—specifically, how to address uneven flooring in grid installations effectively and affordably. To meet this need, we’ve adopted a straightforward and highly reliable solution: column/foot shimming using HDPE shims.
Why Shimming?
Shimming is a low-cost, easy-to-deploy method for correcting floor level discrepancies across the grid. By adjusting the height of individual column feet, you can quickly achieve the required flatness and levelness—crucial for optimal AutoStore system performance.
What We Use
We utilize HDPE (High-Density Polyethylene) shims due to their:
- Durability and moisture resistance
- Ease of handling and on-site cutting
- Availability in multiple thicknesses
These shims are simple to implement and require no special tools or extensive setup. They can be quickly inserted beneath columns to fine-tune levels with minimal disruption to the grid.
Current recommended usage limit: up to 1,000 cells/stacks
Successfully deployed at: 10 active Pio sites
Training & guidance available: from the Pio team
Detailed specifications available upon request
Recommended Shim Types
Material: SIMONA PE 100 Black — View Data Sheet here
| Thickness | Dimensions | Notes |
|---|---|---|
| 2 mm | 240 mm x 220 mm | Stack with glue if needed |
| 4 mm | 240 mm x 220 mm | Stack with glue if needed |
| 10 mm | 240 mm x 220 mm | Stack with glue if needed |
Maximum combined shim thickness: 30 mm. Contact Pio if floor deviations exceed this.
The Shimming Procedure
This section outlines a proven method for floor measurement and shimming. While some variation may be needed depending on your site conditions, the core process remains the same.
Tools You’ll Need:
- Self-leveling rotary laser
- Grade rod (leveling staff)
- Marker or tape
- Floor rails (for layout)
- Lay Out the Floor Rails
Position the floor rails on the floor to identify the locations of each column. - Measure to Identify the Highest Point
Use the self-leveling rotary laser and grade rod to take a height reading at every column position. - Measure to Identify Deviations
Reposition the laser and record the deviation from the highest point directly on the floor rails or beside each column location. - Install Shims to Account for Deviations
Use shims (2 mm, 4 mm, 10 mm) under each column foot to match the highest measured point. Stack as needed, using glue between layers. - Measure Top Tracks
After installing top tracks, use the laser again to ensure they are within tolerance. Adjust using wedges or additional shims if required. Wedges / Grid foot lock (AS-30403) can adjust up to 6 mm.
Figure 1: Shim Placement. Note: Also shim between columns in Y-Direction
Figure 2: Shim placement 
Figure 3 and 4 : Place shims around the edges as shown to support the fence columns (AS-120131)
Floor Tolerances to Achieve
To ensure optimal robot movement and system durability, the floor must meet the following AutoStore standards (AS-55997):
| Measurement Distance | Flatness Tolerance | Levelness Tolerance |
|---|---|---|
| 1.2 m | ±3.5 mm | ±4.5 mm |
| 2.4 m | ±5.5 mm | ±6.0 mm |
Flatness: related to variations over shorter distances, i.e. the short wavelength profile of the floor. Image (a) shows a floor that is level but not flat.
Levelness: related to longer distances, i.e. the long wavelength profile of the floor. Image (b) shows a floor that is flat but not level.
Limitations & Notes
- Shimming is effective for both local dips and wider slope corrections, up to 30 mm in total thickness.
- If your site has deviations beyond this, please reach out to Pio for support.
Questions or Need Support?
We’re happy to assist. If you’d like:
- A guided training session
- Shim sourcing details
- Specification datasheets
Just get in touch with the Pio team.
Let’s keep your installations smooth, stable, and ready for action—right from the ground up.