I have a deck that is 4 ft wide. It is fully cantilevered and supported by 2x8 floor joists that run from a bearing wall in the middle of the house about 15 ft away. I want to extend the deck another 3 ft. I'm told that if the deck had been originally built 7 ft wide it would have met code, but to extend another 3 ft by joining to the existing joists I'll have to run supports to the ground. Is there some connector or joiner for fastening two joists to extend the length that I could use to avoide the supports to the ground?