Make temperature movement visible.

Estimate free thermal movement of steel, aluminum or a custom material over a user-defined member length, temperature range and joint spacing.

Project inputs

Defaults are examples, not recommendations. Replace them with traceable project assumptions.

Confirm the project alloy and reference value.
Used only when custom material is selected.
Uninterrupted length under review.
Material temperature, not only air temperature.
Must be greater than the minimum.
Scenario input, not a recommended spacing.

Screening result

Updated from the inputs at left.

Preliminary decision support only. Confirm inputs, governing standards and final conclusions with the responsible qualified professional before design, procurement or construction.

Method and assumptions

Free movement follows ΔL = α × L × ΔT. The coefficient is converted from micrometres per metre-degree Celsius, then applied to the continuous length and to the lesser of joint spacing or total length.

  • The result is total free expansion across the full temperature swing.
  • Movement from a neutral installation temperature is smaller and direction-dependent.
  • Steel and aluminum defaults are illustrative values only.