There can be a variety of reasons why your nails may peel in layers. You may be using your fingernails as if they are tools. You may be subjecting them to various household chores, household chemicals, and even gardening work. You may be doing these chores without the protection of gloves. You may also be helping them to dry out by applying too many polishes or nail treatments to them. You may also be lacking in some nutrients such as protein, Vitamin D, Vitamin B, iron, biotin,or calcium.