If you are not planning on looting construction sites, or 20 years after the apocalypse, you would not worry about rusty nails and helmets. Hiking gear (especially good hiking boots) and hats are very useful if you plan to walk a lot, in order to stay confortable and not too tired. If you use vehicles, working clothes may be good not as much for their protection, but because they are generally more resistant to wear and will last longer, and they are also generally practical and decently comfortable