well this was pointless

code/game/turfs/simulated/walls.dm

@@ -34,7 +34,6 @@
 	var/sheet_type = /obj/item/stack/sheet/metal
 	var/sheet_amount = 2
 	var/girder_type = /obj/structure/girder
-	var/obj/item/stack/sheet/builtin_sheet = null
 
 	canSmoothWith = list(
 	/turf/simulated/wall,
@@ -46,10 +45,6 @@
 	/turf/simulated/wall/r_wall/coated)
 	smooth = SMOOTH_TRUE
 
-/turf/simulated/wall/New()
-	..()
-	builtin_sheet = new sheet_type
-
 /turf/simulated/wall/BeforeChange()
 	for(var/obj/effect/overlay/wall_rot/WR in src)
 		qdel(WR)

code/game/turfs/simulated/walls_misc.dm

@@ -3,7 +3,6 @@
 	desc = "A cold metal wall engraved with indecipherable symbols. Studying them causes your head to pound."
 	icon = 'icons/turf/walls/cult_wall.dmi'
 	icon_state = "cult"
-	builtin_sheet = null
 	canSmoothWith = null
 	smooth = SMOOTH_FALSE
 	sheet_type = /obj/item/stack/sheet/runed_metal