Barrettes are ‘rectangular’ piles. Similar to rotary bored piles, barrettes are installed using drilling techniques under a bentonite or polymer fluid, that assists in maintaining the stability of the bore during drilling. Unlike bored piles, barrettes are installed using crane- or rig- mounted diaphragm wall cutters, instead of drilling rigs. Barrettes often form the foundations of high-rise buildings and skyscrapers which are subjected to heavy loads and bending moments. Barrettes have the advantage over traditional rotary piles in that they can be installed to larger depths (over 100m), take much heavier working loads, and their verticality is more easily controlled during installation.