Can RAAC really be remediated without moving people out?

In most cases, yes. Because CFRP is applied in place rather than by stripping out and rebuilding the roof, work can be contained and phased around occupants, so a building stays in use rather than being emptied for replacement. Across the tenders we cost, the strengthening scheme keeps occupants in place, with no decant at all.

How do you keep an occupied building safe during the work?

Where the structure has been propped to make it safe, that remains in place until the strengthening is complete. The works themselves are low-intervention, contained and phased, and the building is monitored, so occupants are protected throughout.

Is in-place strengthening cheaper than decanting and replacing?

Almost always, once the cost of temporary accommodation, lost use and the rebuild itself is counted. Across the tenders we cost, a bespoke scheme tailored to that exact roof frequently comes in well below 15 per cent of the cost of replacement; on one tender a roof costed at around £40 million to replace was priced for strengthening at under £4 million, with no decant.

Does this apply to any type of occupied building?

The principle applies wherever RAAC is present in an occupied building, from schools and hospitals to offices, public and operational buildings. Every scheme is assessed and certified by John Staves (CEng FIStructE) on its own merits.

RAAC Strengthening for Occupied Buildings

The single hardest question with RAAC is what to do when people cannot leave the building. Structured Carbon strengthens RAAC in place with bespoke CFRP, contained and phased around occupants, so the building stays in use and there is no decant.

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The RAAC challenge in occupied buildings

Most RAAC is not in empty buildings. It is in schools full of pupils, hospitals full of patients, offices full of staff and public buildings full of people who depend on the service inside. Once RAAC is confirmed, the default route of make safe and then replace forces a hard choice: prop and live with the disruption, or empty the building entirely to strip out and rebuild the roof. Neither sits well when the building has to keep running.

Why occupied buildings need an alternative to replacement

Decanting an occupied building is often the single biggest cost and disruption of the whole job, dwarfing the construction itself. Temporary accommodation, lost use, moved operations and the upheaval to the people inside all stack up before a single roof panel is touched. An approach that restores structural safety while keeping the building occupied removes that burden, which is exactly why in-place strengthening matters most here.

How we strengthen RAAC in occupied buildings

We follow our five-stage RAACSafe™ Protocol. Where a building has been propped to make it safe, that stays in place while Neil Smuts surveys, scans and assesses the RAAC and John Staves designs a bespoke CFRP strengthening scheme to the exact capacity required. The CFRP is manufactured in the UK and installed in place, contained and phased around occupants, and the strengthened structure is monitored. Prop to make safe, then remediate rather than replace.

No decant. Occupants stay in the building while it is strengthened.
Contained, low-intervention working, phased around the people inside.
Safe throughout, with any propping kept in place until strengthening is complete.
A fraction of the cost of decanting, replacing and moving everyone back.

Engineered by named RAAC specialists

Every scheme is designed and signed off by John Staves (CEng FIStructE), one of the UK’s most highly regarded RAAC structural engineers, working from the survey and monitoring of Neil Smuts (MCIOB, MInstNDT), President of the UK Concrete Scanning Standard. Meet the team.

See the numbers on our case study, where, across the tenders we cost, strengthening tailored to the exact roof comes in well below 15 per cent of replacement cost, and read more about CFRP strengthening and RAAC remediation.

Frequently asked questions

Can RAAC really be remediated without moving people out?: In most cases, yes. Because CFRP is applied in place rather than by stripping out and rebuilding the roof, work can be contained and phased around occupants, so a building stays in use rather than being emptied for replacement. Across the tenders we cost, the strengthening scheme keeps occupants in place, with no decant at all.
How do you keep an occupied building safe during the work?: Where the structure has been propped to make it safe, that remains in place until the strengthening is complete. The works themselves are low-intervention, contained and phased, and the building is monitored, so occupants are protected throughout.
Is in-place strengthening cheaper than decanting and replacing?: Almost always, once the cost of temporary accommodation, lost use and the rebuild itself is counted. Across the tenders we cost, a bespoke scheme tailored to that exact roof frequently comes in well below 15 per cent of the cost of replacement; on one tender a roof costed at around £40 million to replace was priced for strengthening at under £4 million, with no decant.
Does this apply to any type of occupied building?: The principle applies wherever RAAC is present in an occupied building, from schools and hospitals to offices, public and operational buildings. Every scheme is assessed and certified by John Staves (CEng FIStructE) on its own merits.

RAAC in a building you cannot empty?

Tell us about the building and any survey already done, and we will advise on strengthening it in place, with no decant.