Frimley Park Hospital is one of several NHS hospitals in England that were built using a form of concrete known as RAAC. RAAC is a lightweight concrete material used extensively in mid-20th century construction. It is now known to present significant structural risks that require major continuous maintenance to keep structurally safe.  

When these risks were identified the Trust implemented an extensive, structural safety and maintenance programme to keep services at Frimley running safely. This involves a major investment in year-round safety inspections by engineers and reinforcing beams and supporting walls.

Q&A on RAAC with Tanka Ambohang, Technical Project Manager in our Property and Facilities Management team. 

What are we currently doing day-to-day to manage RAAC in the hospital? 

Areas and wards affected by RAAC are provided with an ‘Estates Department briefing and action card’, which gives relevant information about RAAC, potential risks, and required actions and considerations. If anyone identifies defects or has concerns regarding the building structure, they can contact the Estates team via email, phone or in person. Upon receipt of these, further investigations are carried out by the Estates or Capital Projects team.

How does our monitoring and inspection regime work? Who carries out checks, and how often?

A professional structural engineer conducts routine surveys of RAAC affected areas. End bearings are enhanced from 45mm to a minimum of 75mm in most accessible areas, in line with IStructE guidance. In addition, annual RAAC roof surveys are undertaken in all areas where failsafe works have not been completed. Where failsafe works have been carried out, RAAC roof surveys are conducted every three years to check for any defects in the RAAC roof planks.

What are the signs to look out for to identify RAAC issues, and how quickly do we respond?

As guidance, the following signs should be observed and, if found to be of concern, necessary action will be taken promptly:

  • Leaks
  • Cracking
  • Movement
  • Dust and gravel
  • Concrete fragments

How are you keeping patients, staff and visitors safe while work is happening?

The Trust aims to fully remediate RAAC roofs by 2030. The priority for which wards require RAAC roof remediation is determined based on findings from the annual RAAC roof surveys, and necessary decant planning is discussed and coordinated with operational teams.

While works are ongoing, project sites are fully hoarded and access is restricted to authorised personnel only. Appropriate signage is installed in affected areas. Operational managers, end users, and affected wards are informed of ongoing works, with regular communications issued to ensure all relevant parties are kept up to date.

For each project, a competent design team is appointed, working alongside the trust’s fire safety managers and Infection Prevention and Control team. Fire safety advice is sought from the Trust Fire Safety Managers, particularly regarding emergency escape routes, which are maintained clear at all times.

In relation to noise, vibration, and dust, these impacts are communicated in advance, and works are carried out only during agreed times. Dust is suppressed using appropriate methods, such as tack mats and suitable tools, to prevent its spread.

Recent independent reports have found Frimley Park Hospital’s RAAC safety and structural maintenance works are effective and suitable to keep services and people safe beyond 2030, but confirms the new hospital is essential and the only way to fully deal with the risk.
Our rolling programme of remedial works to the current building will continue as will close working with the national teams to follow all guidance and requirements, ensuring we continue to provide a safe environment for our patients and staff. This work will remain a priority until the new hospital opens.