You can do it with the action special 224: Scroll Ceiling and by using a dummy sector to control the scroll. The ZDoom wiki isn't very clear of this:https://zdoom.org/w/index.php?title=Scroll_Ceilinghttps://zdoom.org/w/index.php?title=Scroll_Floor
Draw a dummy sector outside the map area so that one of it's linedefs is parallel to the direction where the ceiling texture should scroll. For this line give it the special and arguments:
Action: 224 Scroll Ceiling.
Sector Tag: to the targeted ceiling.
Options: 1 Displacement *and* 4 Scroll by dx/dy.
Scroll: texture only
Horizontal: don't scroll
Vertical: don't scroll
Now the targeted ceiling will scroll when the dummy sector floor or ceiling moves up or down. It'll scroll in one direction when the floor goes down, the opposite when the floor goes up. The speed of the raise/lower will control the speed of the scrolling. The scrolling distance in map units is calculated from:
(1/32) x (the length of the 224 action line) x (the lower/raise movement of the dummy sector ceil/floor)
To scroll 128 units set the action line length to 32 and lower the dummy sector floor by 128.