roof vs roofing

roof and roofing both are nouns.

Word	Noun	Adjective	Verb	Adverb
roof	Yes	No	Yes	No
roofing	Yes	No	No	No

roof (noun)	roofing (noun)
a protective covering that covers or forms the top of a building	the craft of a roofer
protective covering on top of a motor vehicle	material used to construct a roof
an upper limit on what is allowed
the inner top surface of a covered area or hollow space

roof (verb)	roofing (verb)
provide a building with a roof; cover a building with a roof