Mark Saunders, 36, appeared at Cardiff Crown Court on Wednesday 19 October where he plead guilty to one count of arson with intent to endanger life.
Saunders has received a sentence of seven years and eight months in prison, and an extended licence period of two years, after pleading guilty in court.
Detective Constable Matthew Pearce, the officer in the case, said:
“The victims in this case, a family of three, were asleep in bed and were fortunately woken by their neighbour who noticed that their front door was ablaze. Without the reaction of their neighbour, who managed to put out the fire and prevent the spread, this could have led to catastrophic consequences.
“After a joint investigation with South Wales Fire Rescue Service, it was established that Saunders had thrown a flammable liquid over the front door which led to the fire igniting at such velocity.
“I welcome the sentence passed and hope that it demonstrates that such serious crimes will be dealt with robustly by the courts. It should also serve as a reminder of the extreme dangers that lighting flammable liquids can cause and how fast fire can spread.
“I also want to praise the bravery of the family for their support in the police investigation for what was such a traumatic experience.”