A plumber’s tape, also known as PTFE, thread-sealant or Teflon tape is used to lubricate metal threads as well as create a watertight connection. For it to work well though, you need to apply it the right way.
So what is the correct way of applying plumber’s tape? Or rather, which direction should you apply the tape? Clockwise/counterclockwise/back to forth/ front to back and how many wraps.
When installing a shower head, faucet, valve or making any other connection, a plumber’s tape helps create a better seal even without tightening the connection crazily therefore preventing leaks.
To correctly apply plumber’s tape, pull out a small section of the tape and place it flat on the threaded end of the male connection to line up with the second thread. Wrap the tape in the direction of the threads (usually clockwise) about 4 to 6 times nicely overlapped to cover all threads.
The correct direction to apply plumber’s tape is the direction of the thread, which is clockwise for most connections unless the pipe’s connection is reverse-threaded. That prevents the tape from unraveling or balling up during installation.
To know which direction the pipe is threaded, try to connect the male connection to the female connection. If you need to turn the pipe counterclockwise to tighten it, then the connection is reverse-threaded. Remember righty-tighty, lefty-loosey.
One mistake you should avoid doing when using Teflon tape is using too much of it. You will end up with the problem you were trying to avoid in the first place.
Using too much plumber’s tape will prevent the connection from tightening thereby resulting in leaks. 2-3 wraps of plumbers tape is usually sufficient. If however the tape is too thin or when the threads are damaged you can consider up to 6 wraps.
Teflon tape should not be used when connecting plastic (PVC) fittings with female pipe threads (FPT). When applied on plastic male threads, a Teflon tape creates a wedging action during assembly which adds to strain and tensile stress.
Related: Pipe dope vs Teflon tape
How Do You Apply Plumber’s Tape?
Let us now look at how to apply plumbers tape the right way.
- Start by cleaning the connections. Unless you are dealing with new fittings, chances are high that there will be old tape on the threads. You cannot have a proper seal and a proper connection with old tape still on. You need to first remove it as well as pipe corrosions if any. Use a wire brush or an old toothbrush to clean the threads until they are spotless.
- Pull out a small section of plumber’s tape and place its edge on the second thread from the end of the threads. It is important to only pull out a small section of the tape first to prevent it from rolling into a string given how thin and light it is.
- Make sure that the edge of the tape lies flat and that it is not twisted. If twisted cut out the twisted section. Hold it firmly with your finger or thumb to prevent it from shifting. It is also important to ensure that the tape is held perpendicular to the length of the pipe/fitting.
- Start applying the tape in a clockwise direction (unless the connection is reverse-threaded) moving forward while maintain tension on the tape. That is where the problem usually is for most people. If the tape is too loose it will roll into a single strand while if you pull it too hard it will break.
- As you apply the tape, make sure that the wraps are overlapping nicely to make sure all the threads are covered.
- Apply about 4 wraps around the pipe making sure to end just before the end of the threads. It is important not to have Teflon tape covering the edge of the pipe since the excess tape will get inside the pipe and clog shower heads, faucet aerators and other screens.
- When you are done applying the plumber’s tape, break/cut it clean. To do that, place your thumb and press firmly where you want to break it with one hand then pull the roll of tape sharply with your other hand. Smooth the edge round the threads with your finger.
- To check if you have done a good job, start tightening (by hand) the pipe in the fitting and keenly watch between the male and female fittings if the tape is peeling off. If it is, you applied it in the wrong direction.
Mistakes to Avoid When Using Plumber’s Tape
- Not checking the threads direction. Most people assume that all threads have their threads cut in a clockwise direction but that is not always the case. Since you need to apply Teflon tape in the direction of the threads, always confirm direction of the threads prior to applying the tape.
- Pulling out a long section of the tape (or even all of it). You see, the plumber’s tape is usually rolled like toilet paper. You only need to first roll out like 2 or 3 inches of the tape then grab the entire roll with your hand and keep unrolling as you apply more tape on the threads. This allows you to have a good grip and therefore tension on the tape and also prevents it from rolling into a string.
- Applying too much Teflon tape. Threads on the male connection have ridges and grooves which must connect with the grooves and ridges in the female connection. By applying too much Teflon tape, you will be covering them and you will therefore not have tight connection which results in leaks.
- Not applying the tape flat on the threads. You need to make sure that the tape lies flat on the thread. When you apply thick strings of the same, it will have the same effect as applying too much tape.
- Starting the application in the middle of the threads. To have a uniformly applied and overlapped plumber’s tape, you need to start from the end and move towards the front and back. Starting from the middle means that the middle section will be thicker than the ends of the threads.
- Covering the pipe opening with the tape. You need to break the tape just before the end of the threads. This will prevent the tape from entering inside the pipe.
How to Use Plumber’s Tape on PVC (Or Should You?)
When it comes to connecting threaded PVC pipes, the rules are clear. Don’t use Teflon tape, Teflon paste or pipe dope but instead use a proper pipe sealant.
Why is that though? How are PVC pipe threads different from metal pipe threads?
In the case of threaded male PVC fittings, each successive thread is slightly large in diameter that the one before it. The opposite is true for female PVC fittings.
That is called taper and it is standard across the industry. All PVC pipe manufacturers adhere to the specified taper of 1 ½ degrees.
Due to this tapered design of PVC threads, use of plumber’s tape on the male connection would cause the female fitting to stretch/strain because of the wedging action created.
You should therefore avoid use Teflon tape when connecting threaded PVC pipes but instead use a proper sealant. A good sealant is non-hardening, does not add slipperiness and is compatible with plastic.
Teflon Tape Color Coding
Teflon tapes come in different colors with each one of them signifying their intended application. The standard white Teflon tape is mainly used for water connections but outside of that tapes are used for specified applications.
Here is what each color of plumber’s tape mean:
White premium: All industrial applications. Lack of additive or pigmentation makes it a perfect choice for use in food processing, oil and water.
Pink plumbers. This tape is designed to be used in plumbing. The pink color signifies that it is a heavier duty tape compared to the white standard tape.
Yellow Gas: Yellow tapes are made to be used in gas lines (propane, butane, natural gas). It meets all gas companies’ standards.
Green Oxygen: Green-coded tapes are used in oxygen applications for instance gas lines. It has no grease and does not support combustion.
And basically that is pretty much it in as far as Teflon tape applications are concerned. I hope this guide was helpful.