Slab

Slabs are half-versions of their respective blocks.

Obtaining
Stone-type slabs and smooth blocks require a pickaxe to mine. Wooden slabs can be mined with anything, but an axe is quickest.

Natural generation
Smooth stone slabs can be found naturally in villages lining the roof of blacksmith shops and inside the Butcher's Shop and the Blacksmith where they form counters. They are also found in strongholds where they are used in some of the stairs, ledges and torch pillars. Sandstone slabs can be found naturally in desert villages, desert wells, and desert pyramids. Double stone slabs can be found in villages, in the butcher's shop and in blacksmiths. A spruce wood slab serves as a table in igloo basements. Oak, birch, spruce, stone and cobblestone slabs can also be found in mansions.

Dark Oak, Cobblestone, and Mossy Cobblestone slabs generate in pillager outpost.

Smooth sandstone slabs generate in desert village.

Placement
Slabs can occupy either the top half or the bottom half of a block, or both:
 * Placing a slab on top of a block or on the side of a block in the lower half of the side surface will create a bottom slab
 * Placing a slab on the underside of a block or on the top half of the side surface will create a top slab
 * Placing a top and bottom slab of the same type in the same block will create a double slab block

Slabs cannot be oriented vertically.

Behavior


Double slabs are handled as a single block instead of two different slabs; as such, breaking one will destroy the whole block and drop two slabs, as opposed to only breaking one slab within the block. "Double slabs" that are not aligned to the grid (i.e. a bottom slab on top of a top slab) are handled as separate blocks and are broken individually.

Redstone dust can be placed on a top slab, not a bottom slab. Redstone dust placed on a top slab receives signals from redstone dust one block lower and adjacent, but cannot transmit signals down to that block.

Mobs see a slab as a full block. Mobs can spawn on top slabs and double slabs, but not on bottom slabs. In Bedrock Edition iron golems will not spawn even on a top slab.

In Bedrock Edition, mobs standing on bottom slabs with air or another bottom slab below fail to pathfind correctly. They often end up spinning around in a small circle when they try to move.

Due to the way blast rays propagate from an explosion, bottom slabs provide extremely effective absorption to explosions directly on top of them.

Sneaking only reduces the player's hitbox height to 1.65 blocks, and so does not allow the player to walk over a bottom slab with one block of air above it, which is 1.5 blocks of space. A player cannot walk from a block of soul sand directly up to a bottom slab without jumping – this applies not just to soul sand, but to any block $7/8$ of a block high or shorter, because the maximum step height of the player is 0.6 of a block. The player can walk off a bottom slab while sneaking, because the sneaking only prevents falling when the distance is higher than one half block.

If a slab is placed in a water source block, the empty half of that slab's block will be waterlogged. If a top slab is placed in flowing water, a pocket of air is created in the bottom half of the block. In this pocket, the player can breathe and see as clearly as from an air block.

Minecarts on powered rails will not be repelled from a slab. They will, however, be repelled by a slab with a minecart on top.

Falling block entities (like sand, gravel, and concrete powder) will turn into their dropped form if they land on a bottom slab, as when they fall on a torch.

Slabs do not block light.

Fuel
Wooden slabs can be used as a fuel in furnaces, smelting 0.75 items per slab in the Java Edition and Legacy Console editions, and smelting 1.5 items per slab in Bedrock Edition.

Block data
In Bedrock Edition, slabs use the following data values:


 * Double stone slab


 * Double stone slab 2


 * Double stone slab 3


 * Double stone slab 4


 * Stone slab


 * Stone slab 2


 * Stone slab 3


 * Stone slab 4


 * Double wood slab


 * Wood slab

Video
Note: This video is outdated, as red sandstone slabs were added in 1.8, purpur slabs were added in 1.9, and prismarine slabs were added in 1.13.

Trivia

 * Slabs let a small amount of light pass through their edges. This light is only visible when Smooth Lighting is turned on, and does not affect mob spawning or other light-dependent processes.
 * The exception of this is that any light directed through a slab does not affect any block's light values north of the source.
 * Whereas 1&times;1 dents in a flat floor using slabs are darkened as one would expect, 1&times;1 dents created using 2&times;1 or 2&times;2 stairs will darken less, due to having fewer surrounding solid blocks.
 * When water or lava are on top of an upside-down slab, the water dripping particles will appear in midair below the slab instead of from the slab itself, this was fixed in Java Edition 1.13-pre7, but is an intentional feature in Bedrock Edition.