PURPOSE: To connect/disconnect a joint easily to/from a building, and facilitate resin pipe piping work or wall plate renewing work by fastening a washer embedded in a groove of the joint to the building through a disk after the resin pipe connected joint is inserted in a hole of the building.

CONSTITUTION: When piping work is carried out, in the first place, a joint 2 is inserted in a hole 31 bored in a building (wall plate or floor plate) 3. At this time, respective connecting parts 21 and 22 to a resin pipe 1 and a faucet apparatus and so on are formed respectively in both end parts of the joint 2, and a fitting part 25 to a washer 4 is formed on the outer surface in the connecting part 22 of the faucet apparatus and so on. Next, the inside of the washer 4 is fitted to the fitting part 25 of the joint 2. In succession, a disk 5 is superposed on the washer 4. Afterwards, the disk 5 is fastened to the building 3 by means of machine screws 6 and so on through the washer 4, and the joint 2 is installed in the building 3. Thereby, the resin pipe 1 connected beforehand to the connecting part 21 of the joint 2 by means of a bite type ring 24 or a nut 23 and so on, is installed in the building 3 through the joint 2.