have an old shed - has old rusty metal roof- 3'x 14' ribbed galv steel. Should I switch to Home Depot "plastic" (also 3'x14'), or go with same steel sheet? I walk on it often (to sweeep twigs/leaves). Would plastic crack/shatter? Also, if I go with plastic, when I hammer in the alum nails with rubber washers, do I need to pre drill?
Unless it is rusted through I would paint it. Plastic would not be a good walking surface, depending on what is underneath of it (aka is there any sheathing). You'd probably have to pre-drill the holes, and I would use screws instead of nails.