Technician arrived and was shown to upstairs common bathroom by customer. Customer explained that drain had been backing up after slight use, showed technician that the drain would work momentarily before backing up. She explained that she had used Drano however it would not work and the line was still plugged up, noting that this drain would back up every six months or so. Technician explained possibilities however would not be able to determine the exact Caused until disassembling the trap and clearing the blockage. Tech was authorized to complete the work, once Trapboy stepped assembled a major Widing off scale and hair were found in the trap and on the tailpiece. Line was then snaked ensuring That blockage was cleared. Trap was reassembled and tested to ensure that it was properly flowing, and no leaks are present at this time. Tech explained to customer the negative affects of Drano and pointed out to her deterioration of the pop up assembly, offered to replace pop up assembly how