It's fairly common to have hair that is porous on the ends, but not at the roots. That means different parts or your hair require rather different care. How easily your hair becomes porous with just normal wear and tear and weathering depends on a lot of things. In fact, the kind of porosity your hair accumulates can be very different from person to person. How can the ends of your hair become porous? The ends of your hair are the oldest - they have had the most time to accumulate damage. While you up to 11 layers of cuticles covering your hair, if your hair is long there may be few layers left on the ends. Brushing, combing, detangling, sleeping, wearing hats and collars, blowing around in the wind, wearing ponytails and braids and barrettes; these activities cause cuticles to chip or break away completely. Even more dramatic is over-washing the hair (especially if using strong or concentrated detergents), bleaching, highlighting or lightening the hair, permanent dyeing the hair ...