John Burton, the surveyor of the fabric, said that the stonework was now deteriorating too fast for the cathedral's regular maintenance and conservation programme, which cost £1 million annually, to keep up.
The cathedral was at a "critical point in history" and if action was not taken "deterioration will turn into dereliction", he said.
"We don't like to admit that we have had to tie bits of the columns together because we are proud of the building, but we do," he said.
Masons had to "sweep" the exterior walls to remove chunks of wall that were threatening to fall off, and pieces of stone had become dislodged from the towers and fallen on to the roof, he added.
Heather Newton, the head of stone conservation, said that 20 per cent of the hundreds of 12th century Purbeck marble pillars that line the interior walls of the cathedral were bound with tape to prevent them crumbling. She added that a number of crockets, the decorative ends of the pinnacles on some of the towers, had been blown off in storms.
Via Mrs. P.