Can anyone provide advice on travel if they were caught up in the volcano disruption last year?

We're due to fly from CHCH to Heathrow then onwards to Dublin arriving Fri morning (27th May). EU law seems relatively straighforward if you're travelling into or out of EU space on EU carrier but we're travelling with Singapore airlines and I'm not sure if they are covered by a similiar travel rights law.

If I recall correctly at Christmas with the weather disruptions some airlines this side of the pond only took people to their connecting flight and said it wasn't their fault the travel couldn't be completed, although not sure if that's accurate.