The Building Safety Regulator has issued a warning over a “potential structural safety issue affecting reinforced concrete buildings constructed with ‘transfer slabs’.”
A transfer slab is a floor arrangement where a column sits on top of a slab, but does not have a supporting column directly beneath it. The slab acts to support the load from the column and spreads it to the supporting columns below.
The design has been used for 25 years in the UK often in mixed use schemes.
The spotlight has been turned on existing structures after new guidance from the Institution of Structural Engineers last year upgraded new construction methods.
The main concern is over “punching shear in transfer slabs” – a failure mechanism where a high concentration of load causes a column to punch through a reinforced concrete transfer slab which may result in a collapse in part of a building.
The regulator said it was not aware of any building collapse caused by this in the UK.
Building owners are now being advised to seek professional advice if they spot visible signs of distress like cracking.
