Patients with serious psychiatric conditions may have to be temporarily rehoused while extensive repairs are carried out at the Acute Mental Health Inpatient centre in Belfast.

BBC News NI understands rot and black mould on floors and walls have been found in large areas of the building which opened in 2019. One source said the “building is not fit for purpose”.

The centre in the grounds of Belfast City Hospital provides 74 acute mental health en-suite bedrooms, including six psychiatric intensive care beds.

The Belfast Trust said it recently completed investigatory work in two bedrooms to determine the extent of remediation work to rectify damage caused by water ingress.

“The trust is awaiting a report which will detail the proposed remediation work and the anticipated costs as well as a programme for the work required,” it said.

“Both bedrooms remain closed, however, an interim bed is now also in place at the facility which remains operational. No patients have been moved to other sites as a result of this work.”

That report is active, however, BBC News NI understands it will spell out that the problems are chronic and could cost up to £10m in repairs.

Last September, it was revealed that leaking pipes in the building had caused £4m worth of damage to the hospital.

Water had been dripping from various pipes since 2022 causing corrosion within the hot water system and damage to walls and floors.

At the time, it was thought damage was confined to a small area.

But further exploration which involved ripping up two bedrooms has identified more extensive damage, including leaking pipes across the building which had saturated floors and caused metal stud walls to rot and mould to grow on plaster.

One bedroom previously had an ant infestation and was closed immediately.

The current damage is understood to be widespread with vinyl coming away on corridor floors and vanity units in bedrooms leaking.

Sources have told BBC News NI that the damage is “chronic”, “they’ve never seen anything like this” in a new building and that “the place is weeping water.”

Among the extensive repairs are that walls will have to be rebuilt, ceilings either repaired or replaced and insulation changed.

The £33m purpose-built unit, which is the first of its kind in Belfast, cares for some of the most vulnerable mentally ill patients in Northern Ireland.

The single storey building consists of five separate interconnecting buildings which are located around a cloistered courtyard and communal and administration areas.

To protect patients, it’s a secured facility with internal locked doors between areas.

Maintaining security and patient privacy is hampering repair work, with the trust having to explore alternative temporary accommodation, including at Knockbracken Healthcare Park in south Belfast and the Belfast City Hospital.

It’s understood the trust is considering how to proceed with repairs by either closing the building entirely and moving all patients out at once, or carrying out the repairs in a phased approach.

Rehousing patients with acute mental health problems is difficult. Any accommodation must be safe and a locked secure facility.

The facility was built by Graham BAM Healthcare Partnership (GBHP), a joint partnership between County Down-based Graham Construction and Irish firm BAM Ireland.

GBHP has also been involved in Belfast’s new maternity hospital which remains unopened and almost £50m over budget.

BBC News NI understands the trust is paying thousands of pounds per month to flush out taps in the building.

The same partnership won the contract for the new children’s hospital on the Royal Victoria Hospital site – where costs have risen from an initial £250m to more than two and a half times that, with a 10-year delay.

In a statement, the Department of Health said patient safety is its number one priority and they are always vigilant.

It said it was first made aware of ongoing building issues at the facility on 17 September 2024.

It added that Belfast Health Trust Estates are dealing with any issues and confirmed that the trust has not advised the department of any concern in relation to patient safety as a result of building issues.

It added that it will continue to monitor the situation.

Last August, the body which inspects healthcare facilities – the RQIA – issued a notice to the trust telling it to replace doors and door handles at the facility because of potential patient self-harm as a result of ligature risks.

This was to be complied with by 17 February this year, but this has not happened.

In a statement, the RQIA said: “The timeline for addressing these concerns has been impacted by wider estates issues at AMHIC, which must be addressed prior to the replacement of doors/door handles.

“However, the trust has submitted action plans to RQIA, detailing its actions to manage safety concerns highlighted in RQIA’s improvement notice.”

In a statement, the contractor GBHP said: “GBHP are not aware of the building issues at the facility and would assume, therefore, that they are not construction related.”

This is the latest in a series of significant building defects across the Belfast Health Trust.

The Critical Care building opened 10 years behind schedule in 2019 and millions over budget after flaws were corrected, including ripping out equipment that had become out of date.

The ventilation, sewage and drainage systems had been the source of the problems.

All the buildings have haemorrhaged money at a significant cost to the public purse.

Those who have spoken to the BBC News NI have asked how similar problems are allowed to be repeated and why no one in health trust management or the Department of Health has been held to account.