The ceiling collapse at the Apollo theatre in London's West End in December was caused by the deterioration of century-old cloth and plaster ties holding up timber frames, Westminster council has said.

The Grade II-listed theatre will reopen this week, three months after 80 people were injured when about 10 square yards of plaster fell on to the stalls during a performance of The Curious Incident Of The Dog in the Night-Time on 19 December.

The ties, made of hessian and plaster of Paris, were used to lash together timber frames to support the suspended ceiling, and had been in place since the theatre opened in 1901.

A council spokeswoman said guidance would be issued to other theatres and historic buildings built with similar materials.

"Our investigation is still ongoing. However, our inquiry to date has led us to understand why the ceiling at the Apollo theatre failed in December. The principal cause was the deterioration over time of wadding ties which supported the ceiling, thought to be in place since its construction in 1901," she said.

"As a result of this finding, we have a responsibility for health and safety reasons to issue guidance to owners of historic buildings, English Heritage, the National Trust and others regarding ongoing maintenance of similar ceilings."

There were more than 700 people in the theatre at the time of the collapse. Witnesses described chaos and panic as parts of the ceiling began to crumble 45 minutes into a performance.

Masonry and plaster fell on to the stalls, dragging a section of the balcony with it, striking members of the audience and filling the theatre with clouds of thick dust.

The council spokeswoman said work was ongoing to ensure there was no repeat of the episode. "Theatregoers can be reassured that, as a precaution, we are working closely with the Society of London Theatre to roll out this guidance across the theatre community. We are also working with English Heritage with regards to other historic buildings.

"Although all historic ceilings are in some way unique, our guidance outlines what precautions owners can take to ensure the safety of this ornate plasterwork, including thorough checks of suspended ceilings of a similar construction in order to preserve the unique heritage of our great London theatres and historic buildings."

She said it was likely that the investigation would conclude later in the spring. The council said the theatre, which is due to reopen with an adaptation of the vampire film Let the Right One In, was now safe.

The building safety body Structural Safety has raised concerns in recent years about the need for regular checks on the ceilings of performance venues in the UK. It has reported previous instances of ceiling problems and pointed to Home Office recommendations on cinema safety from 1955, prompted by failures in plasterwork.

The director of structural safety, Alastair Soane, said: "Owners of entertainment buildings have to ensure that their structures, including the ceilings, are regularly inspected and maintained."