I found only indirect references, not a clear Supergardan-specific guide, so the safest answer is a general Roblox tile-stacking method based on how building systems usually work.

How to stack tiles

  1. Enter build mode and place the first tile on the grid.
  2. Move the next tile to the edge or top face of the first one.
  3. Use the game’s height/rotation controls, if available, to raise it one step at a time.
  4. If tiles keep snapping back into the same layer, try placing the base tile first, then the stacked tile immediately after.
  5. If the game supports special build pieces like stack tiles or ghost-placement tools, use those to create higher placements more easily.

What usually works

  • Turn on any grid-snap option if the game has one.
  • Rotate the tile before placing if orientation affects stacking.
  • Place from the correct side, since some systems only allow attachment to certain faces or connected points.
  • If stacking is blocked, it may be because the game requires tiles to connect to another tile or to the ground in a specific grid pattern.

Practical tip

A lot of Roblox building games make stacking easier when you place the lower tile first and then use a dedicated height adjuster or stack-mode option rather than trying to free-place both tiles.

If you meant a specific game feature

If “Supergardan” has a custom stacking item, menu, or hotkey, that detail matters a lot, because different Roblox games use different build rules and not all of them support true free stacking.

TL;DR: try build mode, place a base tile, then use grid snap, height adjustment, or a stack-specific tool if the game has one.