ZIPPER STAIRS - a new type of stairway using Nylon-Cement
Picture of ZIPPER STAIRS - a new type of stairway using Nylon-
Cement Stairways have been a part of architecture for thousands
of years. Zipper Stairs are a new type of stairway.  My
inspiration for zipper stairs came from a visit to Mesa Verde
National Park, where the Anasazi Indians had carved hand and
foot holes in the rocks to climb up to their cliff dwellings.
Their holes were small, and were probably chipped out with much
difficulty using crude tools. If one were to expand the holes
until they touched each other, something they did not do, the
end result would be similar to zipper stairs.  Stairs are used
to climb an inclined plane. They have a vertical face and a
horizontal face. As the inclined plane gets steeper, the
vertical face gets higher and the horizontal face gets narrower.
The higher the step, the harder it is on ones knees. As the
horizontal face gets narrower, ones foot eventually doesnt fit
on the step, unless the foot is placed