The most common and most likely answer to this crossword clue is the 6 letter word JOINER
I've seen this crossword clue in The Daily Telegraph
J
O
I
N
E
R
Buddy explains!
The straight part
We know that "One who signs up/member of carpenter’s team" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one who signs up/member of carpenter’s team = joiner.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does JOINER mean?
JOINER noun- A maker of wooden furniture or fittings.
- A woodworking machine used to prepare edges of wooden elements to join to other wood pieces.
- A thing that joins two separate items, e.g. software to connect video or music clips.
- A person who joins societies or organizations.