Pipe Dope vs. Teflon Tape for Water Pipes: Which One is Better?

  • By: Monica Shulz

The main difference between pipe dope and teflon tape.

Is that teflon tape is good to ensure that the waterlines are leak free.

But Pipe dope provides more seal strength. It also offers more pressure tight seal than Teflon tape.  

However, Teflon tape is easier to use. Some people prefer it for certain projects.

There are several other areas that these two differ from each other.

They both help seal the spaces between mating pipe threads.

This is to prevent leaks and make them pressure-tight.

To use them effectively, you must know their differences, advantages, and limitations.

So, in this article, we’ll compare pipe dope and Teflon tape to see which is best for your piping project.

We’ll also give you some tips on how and when to use them for the best results.

Pipe Dope Vs. Teflon Tape For Water Lines

  • Seal strength
  • Piping material
  • Pipe pressure
  • Cost and availability
  • Thread type

Seal Strength

Pipe dope is the clear winner in this category.

It produces seals that are very strong, water-tight, and pressure tight.

Teflon tape produces some decent seals, but it is no match for pipe dope.

Also, Teflon tape is prone to tearing and unraveling if applied wrongly.

However, in some cases, the seal strength of pipe dope can be a disadvantage.

Pipe dope cures inside the fitting to create a hard joint.

This can make it somewhat hard to disassemble a connection made with pipe dope.

So, plumbers mostly use pipe dope when working on a permanent joint. 

For temporary joints, you can go with Teflon tape as it makes disassembly easy.

Note: There are “soft set” and “flexible set” brands of pipe dope, like Megaloc, that claim to be non-hardening. According to their manufacturers, they lubricate the pipe threads and do not harden.

This makes joining and removing the pipes easier.

Piping Material

Pipe dope isn’t the best option for all types of piping materials.

For example, some brands of Pipe dope can break down pipes made from PVC.

Also, excessive pipe dope on plastic pipes can result in overly tight joints.

This can lead to the pipe cracking once the pipe dope cures and sets.

To avoid these, you can try using some of the newer “soft-set” pipe dopes available on the market.

Their manufacturers say they are suitable for both plastic and metal pipes.

Piping Pressure

Water pressure is another important factor to consider when selecting a pipe sealant.

Teflon tape is suitable for standard household fittings.

However, you shouldn’t use it for high-pressure applications.

In cases like this, pipe dope provides the strong seal needed to keep the joints from leaking.

For intermediate pressure applications, you can use yellow Teflon tape.

It is denser than white Teflon tape and provides a better seal.

Thread Type

The type of thread you want to connect will influence the type of thread sealant you’ll use.

If the spaces between the thread are too wide or narrow, you shouldn’t use Teflon tape.

The tape will not be able to form a proper seal to keep the joint leak free.

The same thing will happen if the thread is tapered.

In this situation, pipe dope is the best option.

Cost and Availability

When it comes to cost, both materials are tied.

They are inexpensive materials you can find in just about any hardware store.

However, the shelf life of Teflon tape is longer than that of pipe dope, as the latter can dry up if stored improperly.

On the other hand, Teflon tape doesn’t need special storage, so it lasts longer.

Can You Use Pipe Dope On Water Lines?

Yes, you can use pipe dope on water lines.

Pipe dope provides a strong seal that will keep the line water and pressure-tight.

Also make sure you have unblocked all outside drain pipes as well as inside.

Before you start working on any water lines with your pipe dope. 

Besides, most pipe dope brands are made out of non-toxic materials.

This way, no harmful compounds will be introduced into the water supply.

Can You Use Teflon Tape On Water Pipes?

Yes, you can use Teflon tape on water pipes.

You can use either the standard white Teflon tape or the pink, water-specific Teflon tape.

The pink tape has a greater density than the standard white tape.

This means it can be used for larger pipes and higher pressures than the white Teflon tape.

To ensure a great seal, make sure you install the tape correctly around the pipe’s thread.

Here are some tips on how to do that:

  • Clean the pipe’s thread thoroughly before applying the tape.
  • Start the tape on the second thread to avoid blocking the pipe’s opening.
  • Make sure you wrap the Teflon tape in the same direction as the thread.
  • Pull the tape tight as you wrap it around the thread for a great seal.

So, that’s all you need to know about the Pipe dope and Teflon tape debate!

Overall, pipe dope emerges as the better option.

However, Teflon tape still has applications where it shines.

In any case, it never hurts to have both in your toolbox!