What is Teflon Tape?
When most of us hear the word ‘Teflon,’ we think of frying pans. But in the world of plumbing, it’s usually used in reference to Teflon tape. Teflon tape—generically called PTFE or pipe thread tape—is a thin, “stretchy,” tape you wrap around male pipe threads before screwing them to their female counterparts. It doesn’t have a sticky side, but rather clings to the pipe and itself as you wrap it tightly around the threads. Teflon tape does two important things: One, it acts as a sealant to plug small gaps that might be present after the joint is assembled; and two, it acts as a lubricant so the pipe goes together more easily initially and also comes apart more easily when disassembled. Standard Teflon tape is used on steel, plastic, PVC and copper water pipe. There’s a special type of Teflon tape formulated for gas pipes.
The first tip a plumber will give you about using pipe thread tape is to wrap the tape clockwise around the pipe (as you look at it from the end) so when the joint is assembled the twisting motion tightens, rather than loosens, the exposed end of the tape. And he or she will tell you to wrap it around the pipe three or more times to be most effective. A roll of Teflon tape costs less than $1 and will last most DIYers a lifetime. Buy it and use it.