Light Gray Wool Slab is the half-height slab variant of light gray wool, added to Java Edition in version 26.3 and to Bedrock Edition in the 26.40 preview cycle. Three light gray wool placed in a single row on the crafting grid turn into six Light Gray Wool Slabs. Light Gray Wool Slab belongs to a family of sixteen wool-slab colors in which white acts as the undyed base, and a wool slab of any color can be re-dyed into any other color with a matching dye, exactly like wool blocks. Shears break Light Gray Wool Slab faster than any other tool, and the slab stacks to 64 per slot with slabs of the same color only.

Light Gray Wool Slab also carries wool's vibration-occlusion mechanic: a wool slab placed between a sculk sensor and a vibration source stops the sensor from detecting anything behind it. Sculk sensors cannot detect the placing or breaking of Light Gray Wool Slab, entities walking, sprinting, or jumping on top of the slab, or items dropped onto the slab, and wardens miss the same wool-related activity. Light Gray Wool Slab is easily mined, highly flammable, and offers little resistance against explosions, with a blast resistance of 0.8 in Java Edition and 0.16 in Bedrock Edition. In Java Edition, Light Gray Wool Slab doubles as furnace fuel at 0.25 items smelted per slab, meaning four slabs smelt one item. Builders get the soft pale-gray wool surface at half a block's height for floors, tabletops, and stair accents.