How tall does my ceiling need to be for the J-BARR to work? J-BARR INC. June 03, 2020 12:50 Updated For the best operation your ceiling needs to be a minimum of 9 feet tall. Related articles I don’t see a fitment option for CJ’s and TJ’s. Do you have something that will work for those models? Can I close the back window when using the J-BARR? I just purchased this and about to install, but it didn't come with instructions. Are there some available? I have a Ford Bronco. Will the J-BARR work? Can I use the J-BARR for long term storage? Comments 0 comments Please sign in to leave a comment.