Call us on
+44 (0)1268 777871
When a survey was carried out on the rear flat roof, the deck was found to be constructed in RAAC concrete.
RAAC is Reinforced Autoclaved Aerated Concrete, a lightweight, bubbly concrete used in UK construction from the 1950s to the mid-1990s, particularly for flat roofs, floors and walls. It is now considered a safety risk because it is life-expired and prone to collapse due to its limited durability, with a lifespan of around 30 years; particularly when exposed to moisture. Because of these concerns, buildings containing RAAC, such as schools and hospitals and any other building with this type of decking are undergoing inspections and, in many cases, the buildings have been closed from use and, where feasible, the roof deck is reinforced or stripped out and a new deck installed.
In the case of Cuxton Co-op the roof deck was removed completely and a new timber plywood deck laid-to falls installed. A new Proteus built-up felt system was then installed over the timber, comprising of a Proteus SelfAdhesive Vapour Control, Proteus Pro-Therm PIR insulation bonded in cold applied Pro-Bond Foaming adhesive, (to meet current building regulations of 0.18 U-Value) and then waterproofed with the Ultima Plus two layer felt system, BBA certified for 30 years. On completion the roofs were then supported by a Proteus 25 year guarantee.
Challenges-
The shop needed to be kept open throughout the works. Therefore noise levels needed to be kept to a minimum and no water ingress was acceptable. All the works met with the client’s requirements and were delivered to a high standard.
