Key refurbishment challenges
Explore the top challenges encountered with passive fire protection
renovation by clicking on the hotspots below.
1. Horizontal compartmentation
This is required to stop the spread of fire from one flat to the flat above.
Existing 60’s and 70’s high-rise residential buildings or commercial buildings being converted to apartments will have a flat concrete or ‘coffered’ slab. Dependent on thickness and cover to any reinforcement in the slab, it is likely to need protection to ensure fire resistance is maintained through the slab to the flat above.
The condition and construction of the slab will determine the best option of fire resistance, but it can usually be achieved by using either PROMATECT 250 or CAFCO CP2 cementitious spray.
2. Vertical compartmentation
In most instances, internal partitions within flats will be constructed of plasterboard to provide 30 minutes fire resistance to meet Building Regulations.
Be vigilant however to ensure the vertical partition continues to the underside of the concrete slab and not to a suspended ceiling, where potentially there may be a void between the suspended ceiling and the concrete slab.
Partitions from flats to corridors or forming walls within lift lobbies or escape routes need to be fire rated to 30-120 minutes. This can be achieved using SUPALUX as the partition lining. SUPALUX can be easily decorated for a smooth finish. For fixing details, see the Promat Passive Fire Protection Handbook.
3. Riser shafts & service enclosures
Within existing 60’s & 70’s high-rise residential towers, it is common to have:
- Riser cupboards running the height of the building
- Bin shoots running down to ground or basement level
- Various gas, electric water shafts running the height of the building
Should a fire occur, all of these shafts have the potential to spread the fire throughout the building. As a result, it is vitally important for the shafts to firstly be lined correctly to provide the required fire resistance. SUPALUX can be used to line the shafts, providing a fire and moisture resistant lining.
Secondly, the shafts should be closed off horizontally within the shaft at each floor level, to provide fire protection where services (eg. pipes and cables) run vertically through the shaft. PROMASEAL compound can be used at each floor level to provide permanent shuttering to stop fire spread from floor to floor.
If originally constructed with poor quality concrete or timber, the stairwell lining might need to be upgraded to improve fire resistance. Building Regulations require minimum stairwell widths, so the additional lining often needs to be thin as well as fire resistant and moisture resistant.
SUPALUX fixed directly to the existing stairwell wall linings will meet these requirements. SUPALUX has been tested as a solid partition without any framing to minimise the partition width while maintaining fire and moisture resistance.
5. Concrete column upgrade
Concrete column upgrades are relevant for office-to-residential conversion of 1960’s or 1970’s buildings built with a concrete structural core. The concrete columns are unlikely to meet Building Regulations for residential use and will need to be lined with SUPALUX to give fire resistance to ensure the concrete does not reach a temperature exceeding about 300°C where upon ‘spalling’ can occur. This would result in the concrete losing its design load and potentially collapsing.
SUPALUX is simply fixed direct to the concrete column with non combustible fixings and decorated as appropriate.
6. External facade
Firestopping is required to prevent the spread of fire vertically through the external façade. This is normally referred to as vertical and horizontal cavity barriers which compartmentalises the façade into smaller areas and reduces the risk of a fire spreading vertically from flat-to-flat. A clear ventilation area of 0.032m2 should be maintained.
On buildings over 18m in height, a horizontal fire barrier is required at reach floor level - the reach capability of fire and rescue service equipment such as wheeled escape ladders. The barrier should be installed between the A1 non-combustible sheathing layer and the external façade.
7. Plant room & bin stores
Plant rooms, in which power distribution equipment, control systems and IT infrastructure are accommodated, are risk areas that need to be especially protected from fire and/or blast. Typically located in a basement, the high fire rated areas can be achieved using DURASTEEL, which needs to be installed by a specialist licenced installer, to typically provide:
- High level fire resistance of 120-240 mins for ceilings, barriers or wall linings
- High impact, non-combustible for ceilings, barriers or wall linings
High-rise buildings also have a storage area for bins and waste collection, bicycle storage or similar. These are prone to vandalism, so it is important that wall and ceiling lining materials used are both impact-resistant and non-combustible. This can be achieved using PROMATECT HD.