Notice piece of redwood boarding on deck (5)
I believe the answer is:
adorn
'deck' is the definition.
(thesaurus)
'notice piece of redwood boarding on' is the wordplay.
'notice' becomes 'ad'.
'piece of' says to take the initial letters.
'boarding' is an insertion indicator.
The first letter of 'redwood' is 'r'.
'r' put inside 'on' is 'orn'.
'ad'+'orn'='ADORN'
(Other definitions for adorn that I've seen before include "get dressed!" , "Beautify - decorate - enhance" , "Bedeck" , "Deck" , "Attire" .)