Welcome to SR, When you read the stickies and other posts around here you will learn what you and your family are doing is just promoting his disease and doing the exact opposite of what you need to.
How do you help someone like him? ..... Seek help for yourself! go to Nar-anon. You can only control you. You can't cure his disease he must do it, and he will only do it when the family quits buying his drugs. ** parents giving money, giving a place to live for free.}
I know this sounds harsh but If you continue to enable him to continue he is either going to end up in jail or dead. It takes making him live the consequences of his own choices for them to realize that it is not the right choices. He is an adult and needs to provide everything for himself.
Keep reading and posting. Please seek NAr-anon, your family also.