Updated 25 October 2026. Facts on this page come from minecraft.wiki, minecraft.net and the live Artemis PvP server; sources are listed at the bottom.
Slabs in Minecraft: Recipe and Why Mobs Cannot Spawn on Them
Slabs are half-height blocks. Craft 6 slabs from 3 blocks in a row, or 2 per block in a stonecutter. Place them in the bottom or top half of a space, or stack two into a double slab. The big trick: mobs cannot spawn on bottom slabs, so a slab floor is spawn-proof without any light. Slabs can also be waterlogged.
How do you make slabs?
Three blocks across the middle row of a crafting table make 6 slabs. A stonecutter gives 2 slabs per block for stone types. Wood, bamboo mosaic and wool-type slabs need crafting. Two slabs of the same type in one space make a double slab, which acts like a full block.
Top or bottom?
- Placing on top of a block, or the lower half of a block side, makes a bottom slab.
- Placing on the underside of a block, or the upper half of a side, makes a top slab.
- A single slab in water is waterlogged in its empty half.
Can mobs spawn on slabs?
Not on bottom slabs: they count as non-spawnable. Mobs can spawn on top slabs and double slabs. Covering a base area with bottom slabs is the classic way to stop spawns around farms; see mob spawning and mob farms.
How are slabs used in redstone?
Top slabs carry redstone dust upward in a compact staircase, because dust can climb onto them, though signals cannot travel down slabs. They do not block vertical redstone connections. Basics: redstone basics. On Bedrock a single slab lets light through, while a double slab blocks it.
Building tips
Slabs give roofs a gentle slope, make paths and pond edges, and let you build half-block details. For steps that you walk up, see stairs.
Frequently asked questions
Can mobs spawn on slabs?
Not on bottom slabs; they can on top slabs and double slabs.
Sources
Every fact on this page was checked against these pages; the wording is ours.