Roofing material guide (4)
I believe the answer is:
lead
This clue might be a double definition.
'roofing material' is the first definition.
The definition and answer can be both substances as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'guide' is the second definition.
(lead can mean to usher or guide)
Can you help me to learn more?
(Other definitions for lead that I've seen before include "Guide,direct" , "First news item" , "first name in lights?" , "Metal; show the way" , "Chief performer" .)