Can anyone tell me why metals are or appear to be colder than non metals?

Metals are higher in conductivity and heat capacity than other common materials. They absorb heat from your skin faster than other things, cooling your skin more.

:) Thanks very much.. .

Metal moleculas have free electrons, that makes metals to gain heat and cold faster than non-metals. Metals also expand and contract much more than non-metals.In metal roof application for example linear expansion of metal roof panels is between 1/2" and 1" approximately.Anyway, you will need an insulation under the metal roof.