The Duck Brand Plastic Attic Stairway Cover doesn’t have an R-rating and doesn’t insulate as well as some other products. It ...

Now, the outside of electric wires are usually covered in plastic because it’s a very poor conductor. It hardly conducts any electricity at all, so we can say it’s an electrical insulator.

Flashover performance of ice-covered insulators is a critical area of research in electrical engineering, particularly for ensuring the reliability of power transmission systems in cold climates.