Concrete coring is carried out for one of the following reasons:-

• To form a hole through an area of hard standing, to allow the drilling of a borehole.
• To recover a sample of concrete, masonry or Tarmacadam for inspection and testing.

Prior to drilling, the area is checked for the presence of buried services by examination of the service drawings. All locations are scanned utilising a Cable Avoidance Tool (CAT) in conjunction with a Genny prior to the intrusive works.

The drill bit is cooled and kept clear of cuttings by use of a flushing medium, usually water, which is pumped down the centre of the drill string and returns, with any debris, through the annulus.

The core produced is circular in cross section of the nominal specified diameter throughout the core length. Drill runs will not generally exceed 0.5m in length, and the core barrel will be removed from the drill hole as often as is required to obtain the best possible core recovery.

The resultant core is logged and if necessary subsampled by an engineer or geologist in general accordance with BritishStandard BS 5930

The resultant core hole is generally backfilled with similar material to existing or as required by the contract.