Trapdoor

A Trapdoor (also known as a Hatch) is a block used as a horizontal door that fills a one block space, though the width only takes up part of the block and allows a player to walk in the unoccupied area. It was introduced in Beta 1.6. When placed outside, rainfall, water, and snowfall do not pass through it, but light can shine through.

Uses

When right-clicked, trapdoors will then open by flipping upwards, towards their hinge. Unlike doors, it does not need to be attached to a block. Wooden trapdoors can also be smelted, smelting for 1 and a 1/2 operations.

Crafting

Wooden Trapdoor x2				Iron Trapdoor
None	None	None		None	None	None
Wood Planks	Wood Planks	Wood Planks		Iron Ingot	Iron Ingot	None
Wood Planks	Wood Planks	Wood Planks		Iron Ingot	Iron Ingot	None

Mechanisms

As with Doors, trapdoors can be controlled with Redstone circuitry. Redstone in its charged state will cause the trapdoor to open. Alternatively, redstone in its uncharged state will close the trapdoor. The same can be applied to all pressure plates.

Trivia

• Sand and Gravel, if dropped onto a trapdoor, will break into their item form (similar to how sand or gravel falling on a torch or minecart track will do the same).
• Trapdoors can be pushed by a Piston if there's another block for it to connect to or if the block it is currently connected to is pushed with it.
• As of snapshot 12w40a, trapdoors can no longer be activated by left clicking. Only right clicking opens/closes trapdoors.
• In 1.8, they added iron trapdoors to the game which can be activated only with a redstone pulse, like Iron Doors.
• Trapdoors can create air sockets/stop water when placed in any body of water.
• Trapdoors can be used to seal off underground player-made structures from the outside world, allowing a player to seal out damaging mobs such as Creepers.
• Trapdoors can be found inside of igloos leading to the basement, and can also be found inside of shipwrecks.
• In 1.13, many trapdoor variants were added for the different wood types.
• As of 1.14, trapdoors can be used to start crawling.

Blocks
Natural	Air • Stone • Granite • Andesite • Diorite • Bedrock • Clay ( Terracotta) • Cobblestone ( Moss) • Cobweb • Dirt • Gravel • Coarse Dirt • Bone • Ice ( Packed • Blue) • Spawner • Sand ( Red) • Sandstone ( Red) • Obsidian • Snow • Sponge • Wet Sponge • Stone Bricks ( Cracked • Mossy • Chiseled) • Prismarine ( Dark • Brick) • Sea Lantern • Pumpkin • Bee Nest • Grass Path • Infested Block • Snowier Snow
Manufactured	Bookshelf • Bricks • Wool ( Carpet) • Concrete( Powder) • Conduit • Dried Kelp Block • Fence • Glass ( Pane) • Stained Glass ( Pane) • Glazed Terracotta • Hay Bale • Iron Bars • Jack o' Lantern • Ladder • Painting • Scaffolding • Slab • Smooth Stone • Cut Sandstone • Smooth Quartz • Smooth Red Sandstone • Slime • Snow • Stairs • Walls • Wood Planks • Wood • Beehive • Honey Block • Honeycomb Block • Polished Diorite • Polished Granite • Polished Andesite • Red Nether Brick
Ore	Coal Ore • Diamond Ore • Emerald Ore • Gold Ore ( Nether) • Iron Ore • Lapis Lazuli Ore • Redstone Ore • Ruby Ore • Nether Quartz Ore • Ancient Debris
Mineral Blocks	Block of Diamond • Block of Emerald • Block of Gold • Block of Iron • Lapis Lazuli Block • Block of Quartz • Block of Redstone • Block of Coal • Block of Netherite • Block of Ruby
Utility	Bed • Brewing Stand • Cake • Cauldron • Chest • Shulker Box • Crafting Table • Enchantment Table • Furnace • Jukebox • TNT • Anvil • Blast Furnace • Barrel • Bell • Campfire • Cartography Table • Composter • Fletching Table • Grindstone • Lantern • Lectern • Loom • Smithing Table • Smoker • Stonecutter • Target • Respawn Anchor • Lodestone
Trading/Bartering only	Crying Obsidian
Redstone/Travel	Button • Dispenser • Redstone Lamp • Door • Fence Gate • Lever • Note • Piston ( Sticky) • Pressure Plate • Rail ( Powered • Detector • Activator) • Redstone ( Wire • Torch • Repeater • Comparator) • Trapdoor ( Iron Trapdoor) • Trapped Chest • Hopper • Dropper • Daylight Detector • Tripwire Hook • Observer • Redstone Ore • Block of Redstone
Plants	Cactus • Dead Bush • Chorus Plant • Flowers • Wither Rose • Grass( Grass • Fern) • Leaves • Lily Pad • Melon • Mushrooms( Huge)  • Mycelium • Podzol • Nylium • Pumpkin • Saplings • Sugar Cane • Vines • Cocoa Pods • Wheat • Log • Corals • Kelp • Sweet Berry Bush • Nether Roots • Fungus • Weeping Vines • Twisting Vines
Liquids	Lava • Water
Non-Solid	Fire ( Soul Fire) • Sign • Torch ( Soul Fire) • Banner
The Nether	Glowstone • Shroomlight • Netherrack • Nylium • Nether Brick ( Fence) • Nether Quartz • Nether Gold • Ancient Debris • Nether Wart • Nether Roots • Weeping Vines • Twisting Vines • Fungus • Soul Sand • Soul Soil • Basalt • Magma Block
The End	Dragon Egg • End Stone • Purpur( Purpur Pillar) • Endstone Brick • End Rod • Dragon Head • Ender Crystal
Creative only	Barrier • Structure Block • Jigsaw • Command Block ( Repeating • Chain)
Bedrock Edition only	Stonecutter (old) • Nether Reactor • Light Block • Glowing Obsidian
Technical	Piston Arm • Block 36 • Burning Furnace • Glowing Redstone Ore • Off-state Redstone Torch • Active Redstone Repeater • Flowing Water • Flowing Lava • Farmland • Pumpkin Stem • Melon Stem • Block 97 • Portal • End Portal Frame • End Portal • End Gateway (block) • Missing Texture Block
Unused	Locked Chest
Removed	Cog • Dirt Slab • Cyan Flower • Camera(BE) • Wax Block
Unimplemented	Crying Obsidian (old) • Wax Block
Education Edition only	Element Constructor • Compound Creator • Hardened Glass • Border • Underwater TNT