Can I use Flex Seal tape on a leaky pipe?

If you have a leaky pipe in your home, you may be wondering if you can use Flex Seal tape as a quick DIY fix. Flex Seal is a rubberized coating marketed as a sealant for leaks and cracks. The tape version provides an easy way to wrap and seal pipe leaks.

Flex Seal tape can be a temporary solution for some minor pipe leaks. However, it is not recommended as a permanent fix for plumbing issues. Using Flex Seal tape on pipes has both pros and cons that are important to consider.

The Pros of Using Flex Seal Tape on Pipes

Here are some potential benefits of using Flex Seal tape on leaky pipes:

  • Quick and easy to apply – The tape can be quickly wrapped around a leaking pipe. No special tools or skills are required.
  • Creates a waterproof barrier – The thick, rubberized coating is designed to create a waterproof seal.
  • Seals irregular shapes – The tape can mold around curved and angled pipes.
  • Doesn’t require shutting off main water – Since it’s a surface application, you can apply the tape without shutting off the home’s main water supply.
  • Can be a temporary fix – The tape may temporarily seal a small leak, allowing time to arrange for a professional repair.
  • Inexpensive – Flex Seal tape only costs around $10 per roll, so it’s an affordable DIY fix.

If you’re dealing with a sudden leak and need a fast solution, Flex Seal can be handy. The tape’s flexible, moldable properties allow it to quickly seal around leaky pipe joints, elbows, tees, and other pipe connections. This can buy you some time until a permanent fix can be made.

The Cons of Using Flex Seal Tape on Pipes

However, there are also some downsides to be aware of when using Flex Seal on pipes:

  • Doesn’t fix the underlying issue – The tape only creates a surface seal and doesn’t repair the pipe damage or worn out fitting.
  • Temporary solution – The seal may eventually fail, meaning leaks could reoccur.
  • Pipe may still corrode – Flex Seal doesn’t stop internal or external pipe corrosion.
  • Can obstruct water flow – Wrapping tape around a pipe constricts water flow and may lead to clogging issues.
  • Difficult for a permanent repair – Fully removing the tape seal later is challenging if you need to do a proper pipe repair.
  • Leaks may not be visible – You may not see leaks reoccurring under the tape, leading to hidden water damage.
  • Not a code-approved repair – Building codes require durable, code-compliant pipe repairs.

While Flex Seal tape can temporarily patch a leak, it is not a true pipe repair. The underlying defect still exists, so leaks will likely redevelop. The tape also covers up leaks, which can then go unnoticed and cause major water damage. For these reasons, Flex Seal should only be used as an emergency fix until a real repair can be completed.

Steps for Applying Flex Seal Tape to a Leaky Pipe

If you do opt to try Flex Seal on a minor pipe leak, here are the basic steps to follow:

  1. Turn off water supply – Locate the home’s main water shut off valve and turn it to the closed position. Turn on nearby faucets to drain residual water from pipes.
  2. Clean and dry pipe – Use a wire brush and emery cloth to scrub away dirt, corrosion, and loose paint on the leaky section of pipe. Wipe it down with a dry rag.
  3. Apply primer – For best adhesion, use a PVC, CPVC, or ABS primer matched to your pipe material. Apply a thin primer coat and let it dry.
  4. Wrap Flex Seal tape – Unroll the tape and press it firmly over the leaking section of pipe. Wrap with at least a 1″ overlap until the leak is covered with 2-3 layers.
  5. Smooth the tape – Once wrapped, rub your hands over the tape to conform it to the pipe and eliminate any air bubbles.
  6. Turn on water – Slowly turn the main water supply back on and check for leaks. If needed, add additional tape.
  7. Check regularly – Check the taped area over the next several days for any new leaks or weeping.

Going slowly and adding several overlapping layers will provide the best seal. Be sure there are no gaps or creases in the tape application. The tape will take 24 hours to fully cure.

Best Practices When Using Flex Seal Tape on Pipes

To get the best temporary results from Flex Seal pipe tape, keep these tips in mind:

  • Only use on small leaks – The tape works best on minor leaks from small holes, cracks, or pinhole leaks.
  • Don’t use on high-pressure pipes – Flex Seal is not designed for permanently patching leaks on pressurized hot water pipes or gas lines.
  • Remove corrosion – For best adhesion, scour off any rust, scale, or corrosion before applying the tape.
  • Use pipe primer – A PVC or ABS primer will dramatically improve adhesion.
  • Apply several layers – Wrap the tape with a 50% overlap and use 2-3 layers for a watertight seal.
  • Wrap beyond the leak – Extend the tape at least 2-3 inches beyond the leak in both directions for the best seal.
  • Check for releaks – Carefully inspect the taped area over the following week to check for any new water droplets or weeping.

Avoid using Flex Seal as a DIY solution on large splits, rapidly leaking cracks, or high-pressure plumbing lines. It also won’t permanently patch a leak on corroded or damaged plastic pipes that need replacing.

Professional Pipe Repair vs. Flex Seal Tape

Hiring a professional plumber for a permanent pipe repair is recommended over using Flex Seal in most situations. Here are some benefits of professional pipe repair:

  • Fixes the source of the leak – A pro can diagnose the issue and fix the actual leak, not just cover it up.
  • Long-lasting repairs – Plumbers have access to code-approved fittings, seals, and patches that provide reliable, permanent fixes.
  • Prevents water damage – A proper repair will stop a leak before major water damage can occur in walls or subfloors.
  • Improves water flow – Pipe repairs are less likely to clog or restrict water flow compared to tape wraps.
  • Meets building codes – Licensed plumbers ensure repairs meet local building and plumbing codes.

Professional repairs do cost more than Flex Seal tape, but keep in mind that tape often provides only a temporary fix. This means you could end up paying a plumber anyway if leaks recur under the tape. Investing in a high-quality repair the first time is usually worth the cost in the long run.

When to Call a Professional Plumber

Here are some signs that a leaky pipe needs professional repair rather than a DIY Flex Seal tape fix:

  • Large leaks or ruptures – Flex Seal won’t properly seal around large holes or cracks wider than 1/4-inch.
  • High water pressure – Tape should not be used on pipes supplying hot water heaters, refrigerators, or other high-pressure applications.
  • Underground leaks – Leaks in buried water service pipes require excavation to access and repair.
  • Sewer pipe leaks – Sewer pipes require specialized repair techniques due to hazardous waste.
  • Gas pipe leaks – Never attempt to repair leaking gas pipes yourself. Call the gas company immediately.
  • Shower/tub spouts – Tape won’t create a lasting seal on constantly moving showerheads or tub spouts.
  • Extensive corrosion – Severely corroded pipes need replacing, not taping over.
  • Preventative maintenance – Routine plumbing checkups can find and address small leaks before they become big problems.

Plumbing problems will only get worse over time if not repaired properly. Flex Seal is not meant as a DIY alternative to professional pipe repair services for serious or complex leaks.

Signs Your Flex Seal Repair Has Failed

Here are some warning signs that a Flex Seal tape repair has failed and the leak has resumed:

  • New water spots appear around the taped area
  • Drop in water pressure throughout your home
  • An increase in your water bill, indicating a possible leak
  • Bubbling or dripping under the tape
  • Water puddling around the base of the pipe
  • Humidity or dampness around the pipe despite no visible leaks
  • Peeling, bubbling, or lifted areas of the tape
  • New drywall cracks or soft drywall near the pipe
  • Mold or mildew growth on walls near the pipe

Catching Flex Seal failures quickly can prevent damage from water that may be leaking beneath the tape seal. If you notice any of these warning signs, inspect under the tape using a flashlight. Any weeps or moisture indicate it’s time to call a plumber to properly repair the leak.

Improving Flex Seal’s Temporary Repair Effectiveness

You can improve the temporary leak-sealing ability of Flex Seal tape with these tips:

  • Thoroughly clean and dry the pipe first
  • Lightly sand and wipe down plastic pipes for better adhesion
  • Apply pipe primer before the Flex Seal tape
  • Wrap the tape using at least a 50% overlap
  • Press and smooth the tape firmly into shape as you wrap
  • Wrap the tape 2-3 inches beyond either side of the leak
  • Cover the leak with 2-3 full tape layer thickness
  • Use aluminium foil to add a second barrier layer over the tape
  • Watch for water droplets or weeping under the tape indicating releaks

While Flex Seal can be handy in an emergency leak situation, it still only offers a short term, DIY patch. For any significant plumbing leaks or failures, call a professional plumber for a safe, legal repair that will permanently resolve the issue.


Flex Seal tape can temporarily seal small leaks on low-pressure water pipes. However, it is not a recommended permanent solution due to releak risks. The tape only seals the surface while the underlying pipe defect continues deteriorating. For a lasting repair, it’s usually better to hire a professional plumber to properly diagnose and fix any pipe leaks using code-approved methods and materials.

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