Stephen McKeown found his back becoming increasingly painful after the fall in November 2010, a court heard.
A judge said he had come to the view that Inverclyde Council’s system for carrying out gritting at such premises was a reasonable one.
Janitors were expected to treat paths leading up to the school as a priority and complete the work before 9am – with other areas such as fire escapes where Mr McKeown fell – salted afterwards.
However, Lord Burns said the system “existed only on paper and was never actually put into action”.
The judge said that had Mr McKeown known to treat only areas given priority before 9am, he would have had more time to concentrate on fire steps at the school afterwards and it was likely that he would have taken more care over them.
The council pointed out that Mr McKeown, 61, had been a janitor for many years and had slipped on fire steps he had salted earlier in the day which at the time would have been in full view, and he would have been in a position to see any ice.
But Lord Burns said: “I have come to the view that the pursuer should not be held to be responsible for his accident to any extent. In proceeding to apply salt to these premises as he did, he was using his own system without any assistance by way of instruction or training from his employers. He cannot be blamed for proceeding as he did.”
Mr McKeown raised an action suing the local authority at the Court of Session in Edinburgh following the accident. Damages were agreed at £30,000, but liability was in dispute.
He had worked for 18 years as a janitor at various schools. At the time of the accident, he was working at St Stephen’s High School in Port Glasgow and was asked to go to St Francis Primary in the town to provide cover.
On the day of the fall, Mr McKeown arrived at St Francis at around 7am. The grounds were icy in places and he began salting paths and playgrounds, working his way round the building. He had thrown salt by hand on steps leading up to fire escapes at classrooms.
Lord Burns said: “He was using a system which he had used for the whole of the 18 years of his employment with the defenders, for which he had no formal training or instruction.”
After 9am, he had salted other areas not already covered, such as the car park. During break time it was his duty to monitor pupils in the playground and to pick up litter.
Two girl pupils had drawn his attention to a condom lying at the top of a fire escape and he went to retrieve it with a litter picker when he slipped and fell against a wall. Lord Burns said in a written judgment: “He recalled that he had salted the area earlier that morning, but that it was in the shade and had thus taken longer to thaw.”