There is a principle that guides cantilevers in slabs or beams, and it is extremely crucial on site.The cantilever is one of the most sensitive structural elements you can handle. A single error in a cantilever can lead to instant failure and once it fails, there is often no repair that can fully fix it.Principle number one: TIE -BACK.You must always provide a proper tie-back for any cantilever, whether it is a beam or a slab.Your reinforcement for the cantilever must not just stop at the edge.