Hundreds of bathrooms at Scotland’s £1 billion superhospital are set to have their floors ripped up and replaced after ‘substandard’ material allowed mould and damp to spread to patient rooms.

The Mail on Sunday can disclose that the products used to line the floors of the 1,109 patient ensuite bathrooms at Glasgow’s Queen Elizabeth University Hospital (QEUH) allowed water to penetrate through to the wards below.

Now hospital chiefs face another significant outlay in a building which opened just 12 years ago and has already racked up £70 million in repairs.

Scottish Labour health spokeswoman Jackie Baillie said: ‘These jaw-dropping findings demand urgent answers from NHS Greater Glasgow and Clyde and the SNP government.

‘It is shameful that shoddy construction has been allowed to threaten patient safety at the QEUH for so long.

‘The SNP must explain how this happened, what it knew and how it will make sure every ward of this hospital is safe.’

According to a senior source, investigators discovered the widespread flaw with ensuite bathrooms while investigating the latest patient infections in the bone marrow transplant unit, ward 4B, in February.

Several rooms in the ward had to be closed after black marks appeared on the ceiling, prompting concerns about leaks and mould from the ward above. Former health minister Neil Gray confirmed that mould had grown from swabs taken during the investigation.

The source said: ‘They found that substandard lino had been used in the wet rooms of all the ensuite bathrooms, which has allowed water to permeate below.

‘They also found mould growing, which is clearly not ideal if that is then seeping into the ceiling of the patients’ rooms underneath. It all has to be replaced entirely, everywhere.’

Replacing every floor in the QEUH’s ensuite bathrooms could take years and may see parts of the hospital shut down while contractors carry out the work, the source said.

Scottish Conservative health spokesman Miles Briggs said the latest development shows that the hospital was opened too soon.

He added: ‘This shocking revelation is yet more proof that the SNP rushed the opening of this flagship hospital for political reasons.

‘It’s clear that this hospital wasn’t ready to open, but Nicola Sturgeon turned the screws. This had tragic consequences and now taxpayers are going to have to shell out for a costly retrofit.

‘The dire level of hygiene at the QEUH is putting patients at an unacceptably high risk of contracting an infection. John Swinney must be fully transparent and explain what steps his government will take to address these serious issues.’

The latest debacle comes after we previously revealed that two patients were being treated for fungal infections on a cancer ward contaminated by mould and water leaks, which is now set to be replaced completely.

The First Minister and his Health Secretary asserted that the site was safe.

Health bosses are also in the process of replacing all 500 fire doors at the stricken site at a cost of £16 million.

The QEUH is at the centre of a public inquiry after dozens of patients, mainly children with cancer, contracted rare infections there. 

The deaths of some patients, including ten-year-old Milly Main and 73-year-old Gail Armstrong, are being probed by the Crown Office, with NHS Greater Glasgow and Clyde named as a suspect in the corporate homicide investigation.

A spokesman for the health board said: ‘NHS Greater Glasgow and Clyde has a range of ongoing legal proceedings against the main contractor as a result of these significant failures, which include defects with ensuite facilities.

‘We are working with designers and specialist contractors to develop a long-term refit design option for all ensuite rooms in due course.’