PVC pipe is durable and water-resistant, making it the perfect material for applications where the pipe will need to be submerged. But what happens when you need to repair piping or fitting underwater? While repairing and solvent cementing dry PVC is often easier, it is possible to repair PVC underwater. With the right water-safe materials, your pond fountain, pool pump, or other submerged structure will be ready to go in no time.
Applications Where PVC May be Submerged
PVC pipe is designed for a variety of uses, from drain pipes to landscape drainage and even craft projects. In some instances, PVC may even need to be submerged in water. Some underwater uses include:
• Floating docks
• Irrigation systems
• Septic drain lines
• Man made ponds and water features
Difficulty in Cementing PVC Pipe Underwater
Locating a leak or crack in your submerged PVC can be challenging, especially if the water is murky. Repairing a leaky underwater pipe, however, can seem like an impossible task. Fortunately, it’s not impossible. It all comes down to the right materials.
Standard solvent cement and epoxies, for example, are not designed to be applied in wet environments, and many non-cement options, like pipe repair wrap, are not recommended for underwater use. In order to ensure your repair will hold, even in pressurized applications, be sure to select a solvent cement or cement designed for underwater use.
Cementing PVC Pipe that is Submerged in Water
Once you’ve selected an underwater cement for repairing your submerged PVC pipe, you can begin your repair. As always, follow the directions on the water-safe cement as you begin to repair the PVC pipe, and be sure to pay specific attention to the time it takes for the solvent cement to cure. Consider wearing gloves as well.
1. Locate the supply line for the leaking PVC pipe and turn the valve clockwise to ensure water is not flowing through the pipe as you repair it.
2. The underwater cement will likely come in two parts. Squeeze equal parts of each onto a piece of cardboard and use a putty knife to mix it well. You’ll know it’s mixed properly when it has a uniform color and appearance.
3. Load the putty knife with the right amount of cement. It’s recommended to use twice the amount of cement needed to cover the size of the PVC pipe leak.
4. Apply the underwater PVC cement directly to the pipe in the area where the leak or crack occurred. You’ll need a thick layer of cement to seal the pipe. There is no need to wipe off the excess cement.
5. Allow the cemented PVC pipe to cure for at least 24 hours before use.
Alternatives to Gluing Submerged PVC Pipe
While underwater cement is usually easy to find and purchase, you may be looking for alternative solutions. If the pipe is submerged in a small amount of water, it might be possible to remove the water surrounding the pipe before you begin work. This can be done easily with a wet vac. If possible, you might be able to raise the pipe out of the water, as well. If you choose either of these methods, be sure to fully dry the area around the leak or crack before applying standard PVC solvent cement, and keep water away from the pipe for at least 24 hours to give time for the cement to cure.
In applications where the pipe isn’t pressurized, it may also be possible to repair the submerged PVC pipe without solvent cement altogether. While many repair tapes are considered waterproof, a small number of them can also be applied to underwater PVC pipes. You can also consider using a rubber coupling with clamps. If these methods do not fix the crack or leak, you will need to use the underwater gluing method outlined above.
Ensuring a Successful Underwater Pipe Repair
Repairing a cracked or leaking PVC pipe can always be a bit tricky, but when the pipe is submerged, the process may be a bit more tedious. Fortunately, with the right materials, you can repair PVC pipe even if it’s completely underwater. First, turn off the water source to your pipe and purchase underwater PVC cement. Next, mix the two parts of the underwater cement together to activate its adhesive properties. You’ll know it’s fully mixed when the color and texture is completely uniform. Using a putty knife, apply a thick coat of the cement to the surface of the pipe. Then allow it to cure for at least a day before turning on the water source.