Build beams, say (5)
I believe the answer is:
raise
'build' is the definition.
(raising is a kind of building)
'beams say' is the wordplay.
'beams' becomes 'rays' (I've seen this before).
'say' indicates a 'sounds like' (homophone) clue.
'rays' sounds like 'RAISE'.
(Other definitions for raise that I've seen before include "Call up" , "Exalt" , "Heighten" , "Breed" , "Care for during childhood" .)