Adds (dirty) steel tiles.

code/game/objects/items/stacks/tiles/tile_types.dm

@@ -87,6 +87,12 @@
 	singular_name = "red floor tile"
 	icon_state = "tile_red"
 
+/obj/item/stack/tile/floor_steel
+	name = "steel floor tile"
+	singular_name = "steel floor tile"
+	icon_state = "tile_steel"
+	matter = list("plasteel" = 937.5)
+
 /obj/item/stack/tile/floor_white
 	name = "white floor tile"
 	singular_name = "white floor tile"

code/game/turfs/flooring/flooring.dm

@@ -92,6 +92,13 @@ var/list/flooring_types
 	has_damage_range = null
 	flags = TURF_REMOVE_CROWBAR
 	build_type = /obj/item/stack/tile/floor_red
+    
+/decl/flooring/tiling/steel
+	name = "steel floor"
+	icon_base = "steel"
+	has_damage_range = null
+	flags = TURF_REMOVE_CROWBAR
+	build_type = /obj/item/stack/tile/floor_steel
 
 /decl/flooring/tiling/white
 	name = "white floor"

code/game/turfs/flooring/flooring_decals.dm

@@ -79,6 +79,9 @@ var/list/floor_decals = list()
 	name = "brown corner"
 	icon_state = "corner_brown"
 
+/obj/effect/floor_decal/corner/brown/full
+	icon_state = "corner_brown_full"
+
 /obj/effect/floor_decal/corner/white
 	name = "white corner"
 	icon_state = "corner_white"

code/game/turfs/flooring/flooring_premade.dm

@@ -64,6 +64,11 @@
 	icon_state = "red"
 	initial_flooring = /decl/flooring/tiling/red
 
+/turf/simulated/floor/tiled/steel
+	name = "steel floor"
+	icon_state = "steel_dirty"
+	initial_flooring = /decl/flooring/tiling/steel
+
 /turf/simulated/floor/tiled/white
 	name = "white floor"
 	icon_state = "white"