roof vs tile roof

roof and tile roof both are nouns.

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

As nouns, tile roof is a hyponym of roof; that is, tile roof is a word with a more specific, narrower meaning than roof:

roof (noun)	tile roof (noun)
a protective covering that covers or forms the top of a building	a roof made of fired clay tiles
protective covering on top of a motor vehicle
an upper limit on what is allowed
the inner top surface of a covered area or hollow space

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