The Red Adobe Wall is a smooth muted pale red building-block that looks the same on all 6 sides. You can craft it in your Crafting Menu (default key "q") after finding and learning the according rare crafting Recipe Book.
The rare crafting Recipe for this block can be discovered in Treasure Chests that randomly spawn in darkness, especially in Iron Treasure Chests that spawn on blocks of the Lava layer underground, or in Diamond Treasure Chests spawning on blocks of the Corruption layer underground.
Recipes can also be learned in player-created Adventures.
In order to permanently add the recipe to your crafting menu (and so it can be carried over to all other Creativerse gameworlds like all rare and store-bought Recipes), this recipe has to be learned at first by right-clicking on it in your inventory/bag or dragging it with the left mouse-button over your player character model on the right side of the inventory.
To craft 8 blocks of Red Adobe Wall at a time, you'll need (as of R44 in June 2017)
- 2 Adobe Bricks made from Mud in a Forge
- 4 (blocks of) Canyonstone or 4 Ruddy Canyonstones or 4 Dark Canyonstones
- 1 Melted Wax made of Beeswax in a Forge or looted from Wood Treasure Chests or Stone Treasure Chests
- 2 Stone Rods made of Stone, Limestone or Bedrock in a Processor
- 1 Red Pigment made of Red Flowers from Ashenwood-trees in a Processor or found in Obsidian Treasure Chests
Blocks of Red Adobe Walls can be put into a Processor to be cut into either 2 Red Adobe Slabs or 2 Red Adobe Slopes each. No crafting recipe is required for this. Red Adobe Slabs can then be made into Red Adobe Stairs. Red Adobe Slopes can be further cut into inner and outer roof corners in a Processor.