Lol, I've never a seen a zombie movie were zombies can climb stairs. They're mostly to lazy too. Think back to Night of the living dead by Romero. All you need is a heavy door. Though that was 66, I think. Maybe 67. Eh, with the 21 century it's probably a worst radiation leak. So yeah, it might be possible. If the mindset is still there...like in Day of the dead? OH WAIT. Totally forgot about that other British movie..but those were mutants..or Zombies? I don't remember. But they climbed stairs..28 weeks later..came out in 2002.

:feesh:
rant.