I'm in the process of demoing a 1/2 bath where I will be useing instead for a hallway. The sink plumbing is right in the middle of where I will be installing the door to new hallway. My problem is I need to capp off 1/2" galvanized pipe under the slab but keep water flowing to another bathroom beyond. My question is, is there a compression fitting that can be used and be dependable or does it need to be threaded. The line is running directly beneath a bearing wall so i didn't want to jackhammer back to main supply line. I have no threading tool. Any help would be appreciated. Thanks