The Judge, Mr Philip Richards, said the fire was a "very irresponsible act" with "consequences that were devastating". He acknowledged that Mr Goulding has considerable learning difficulties which is why he took so long to accept responsibility.
Mr Goulding has been remanded in custody and will be sentenced tomorrow at 2pm at Newport Crown Court.
More top news
Mainly dry with lengthy clear spells overnight and just a few showers likely, especially in the north and west.
Ysgol Uwchradd Caergybi became the UK's first comprehensive 65 years ago. Academies are now dominant in England, but certainly not in Wales.
Dry for most, but a few showers likely.