how to waterproof extension cord connection


Hello How To Connects Friends, welcome to today’s article on how to waterproof extension cord connection. Extension cords are an essential part of our daily lives, but they can be quite hazardous if not used or maintained appropriately. Therefore, it is crucial to ensure extension cords are waterproof, especially when they will be exposed to elements such as rain or snow. In this article, we will be discussing how to waterproof an extension cord connection to ensure safety and durability.

What are Extension Cords and Why are They Important?

Extension cords are long and flexible electrical wires with a plug at one end and a socket at the other. They are mostly used to extend the reach of power outlets. They are lightweight, portable and can be very useful in homes, offices, and outside work spaces. Extension cords are also important for outdoor activities like camping, gardening, and construction work because they allow you to connect electrical devices to power sources in remote locations.

Types of Extension Cords

There are many types of extension cords available in the market, including:

Type Description
Indoor Cords These cords are designed for indoor use and should not be used outdoors.
Outdoor Cords These cords are designed to be waterproof and can be used for outdoor activities.
Heavy-Duty Cords These cords are designed to handle high voltage and resistant to wear and tear.
Multi-Outlet Cords These cords have multiple outlets along their length, allowing you to connect multiple devices.

Why is Waterproofing Extension Cord Connection Important?

Water and electricity do not mix well. When an extension cord is exposed to water, it can become a serious hazard and lead to electrical shocks or fires. This is why waterproofing an extension cord connection is crucial to keeping you and your family safe.

Tools and Materials Needed for Waterproofing an Extension Cord Connection

Here are the tools and materials you will need to waterproof an extension cord connection:


  • Wire Strippers or Scissors
  • Wire Connectors
  • Heat Shrink Tubing
  • Heat Gun
  • Tape Measure


  • Extension Cord
  • Waterproof Adhesive
  • Silicone Sealant

How to Waterproof an Extension Cord Connection

Step 1: Cut and Strip the Extension Cord

Use wire strippers or scissors to cut off the damaged or frayed part of the extension cord. Strip the insulation off the three wires (black, white and green) for about half an inch.

πŸ” Pro Tip: Make sure you plug off the cord from the power outlet before you start working on it.

Step 2: Connect the Wires

Connect the wires of the extension cord to the wires of the connector using wire nuts or twist-on connectors. Make sure each wire is connected to its corresponding color code (black to black, white to white and green to green).

πŸ” Pro Tip: Twist each wire securely and tug on it gently to ensure it is firmly connected.

Step 3: Slide the Heat Shrink Tubing Over the Connector

Slide the heat shrink tubing over the connector until it covers the exposed wires. Ensure the tubing is longer than the connector to avoid exposure to water.

πŸ” Pro Tip: If you’re working on a multi-plug extension cord, ensure each wire is connected to the right connector.

Step 4: Apply Heat to the Tubing

Use the heat gun to apply heat to the tubing, making it shrink and seal the connector tightly. Ensure you move the heat gun around the tubing to make sure each part gets enough heat. Repeat the process for each connector.

πŸ” Pro Tip: Leave some space between the tubing and connector to avoid heating the wire.

Step 5: Apply Waterproof Adhesive

Coat the connection points with waterproof adhesive. Make sure you cover the tubing and connector completely. The adhesive helps to prevent water from penetrating the tubing and corroding the wire inside.

πŸ” Pro Tip: Do not glue the tubing completely shut to avoid trapping moisture inside.

Step 6: Apply Silicone Sealant

Apply silicone sealant on the connection points to create an additional waterproof barrier. Spread the sealant evenly across the tubing and connector.

πŸ” Pro Tip: Apply the sealant generously to ensure maximum protection.

Step 7: Allow the Connection to Dry

Wait for the sealant to dry completely. Ensure the connection points have dried before plugging the extension cord back into the outlet. This step is crucial to avoid short-circuiting the connection and causing damage to your devices.

πŸ” Pro Tip: Do not handle the cord for at least 24 hours after sealing to avoid disturbing the connection points and damaging the seal.


Q: What type of extension cord is best for outdoor use?

A: An outdoor extension cord is best when waterproof, UV resistant and highly durable. It should have a heavy-duty electrical rating of 10 – 12 gauge wire and a grounded three-prong plug design.

Q: How long can an extension cord be?

A: The maximum extended length you can use depends on the gauge wire of your extension cord. For safety, avoid extending a cord beyond 100 feet for general uses.

Q: Can I use an indoor extension cord outside?

A: No, indoor cords are not designed for outdoor use and can be dangerous as they are not waterproof.

Q: Can I connect multiple extension cords together?

A: It is not recommended to connect multiple extension cords together as this can cause voltage drops, which can lead to damaging of equipment or fire.

Q: Can I use electrical tape to waterproof my extension cord connection?

A: Electrical tape is not recommended as it can peel off over time, leaving the cord unprotected. Waterproof adhesive and silicone sealant are the best waterproofing materials to use on extension cords.

Q: Why should I replace a damaged extension cord instead of repairing it?

A: A damaged extension cord can be an electrical hazard that can cause severe injuries or even death. Therefore, it is best to replace a damaged cord rather than attempting to repair it.

Q: Can I store my extension cord in wet conditions?

A: No, do not store your extension cord in wet or damp conditions as this can damage the wire and shorten the lifespan of the cord.

Q: What should I do if I accidentally cut the cord of my extension cord?

A: Unplug the cord from the wall, and replace it with a new one. Do not attempt to splice or repair it.

Q: What type of wire is best for extension cords?

A: Copper wire is the best for extension cords because it is a good conductor, flexible and durable.

Q: Should I unplug my extension cord when not in use?

A: Yes, it is recommended to unplug extension cords when not in use to prevent electrical shocks that can lead to fire hazards.

Q: What is the recommended wattage capacity for extension cords?

A: It is recommended to use extension cords with a wattage capacity that can handle the electrical load of your devices. For example, a 12-gauge extension cord can handle a load of up to 1,800 watts.

Q: What should I do if my extension cord gets wet?

A: Unplug it immediately and dry it out completely before using it again. If the cord appears damaged, do not use it and replace it with a new cord.

Q: Can I use an extension cord for my electric lawnmower?

A: Yes, you can use an extension cord for your electric lawnmower. Ensure the cord is long enough to reach the farthest end of your yard and has the appropriate gauge based on the power rating of your mower.

Q: Do I need a grounded extension cord?

A: Yes, a grounded extension cord is essential for safety purposes as it helps to minimize the risk of electric shocks and fire hazards.


There you have it, How To Connects Friends. By following the steps listed above, you can waterproof your extension cord connection and keep it safe from any water hazards. Always remember to check the cord for any damage before you use it, and make sure you store it properly when not in use. Avoid using indoor cords outdoors and ensure you choose the right extension cord for your devices.

If you have any questions or feedback, please leave a comment below. Thank you for reading to the end. You are now an expert in waterproofing an extension cord connection. Stay safe and enjoy the convenience of your extension cord!


The information in this article provides general advice. It is your responsibility to verify its accuracy and to perform due diligence in connection with any electrical wiring or installation project. Consult a qualified electrician or handyman before undertaking any project. Use of this information is at your own risk.