hit the roof

VERB
12 LETTERS · STARTS WITH H

hit the roof is a valid 12-letter word worth 19 points in Scrabble and 17 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
H4I1T1T1H4E1R1O1O1F4
4 + 1 + 1 + 0 + 1 + 4 + 1 + 0 + 1 + 1 + 1 + 4 =19 PTS
DOUBLE WORD → 38TRIPLE WORD → 57
MEANING

What does hit the roof mean?