Build a tower of ice cubes

A tower of slippery ice cubes might sound impossible to build, but adding a little salt makes it much easier!

Materials

Ice - 4-8 cubes

Salt

Plate or tray

Instructions

Try to stack the ice cubes. They will topple off each other.

Leave the ice cubes to melt for a few minutes.

Try to stack the cubes again, but this time sprinkle salt over the top of each one before adding the next.

You should now be able to build a small tower of ice cubes!

ice cube towers made with ice cubes and salt

Extension Task

Use the same concept to lift an ice cube with a piece of string.

How does it work?

Salt lowers the freezing point of water. When you sprinkle salt on the top of an ice cube, it starts to melt. You can see in the photo above that the once smooth surface has become rough. This is why salt is used to grit roads in winter.

The salt water refreezes on the surface of the ice cubes, which sticks them together, allowing you to build a tower of ice cubes.

Science concepts

Changes of state

Last Updated on July 3, 2025 by Emma Vanstone