Duct tape is so useful that people use it for various things, from fitness workouts, space explorations, dressmaking, and survivalist emergencies to home repairs. It almost feels like duct tape puts the “all” in “do-it-all.” However, every do-it-all has its limit, and you may wonder if duct tape is waterproof.

Duct tape is not fully waterproof. However, it stays water-resistant on most surfaces for a decent amount of time. Duct tape will temporarily fix a wet problem, but it can’t do it permanently, so it may not hold up for as long as you would want, especially on a porous surface.

Keep reading as I discuss further why duct tape isn’t waterproof and how long it’ll hold up. I’ll also share tips on how to get the best water resistance with your duct tape and suggest alternatives to duct tape you can consider. Keep reading.

Why Isn’t Duct Tape Waterproof?

Duct tape isn’t waterproof because it’s designed to be water-resistant only. That means duct tape can’t completely block out water and offer a high level of protection against water. Because duct tape is only water-resistant, it can block out water but can’t hold up for very long.

Duct tape is made of three layers of material: the sticky bottom layer with a coat of adhesive that’s usually gotten from natural rubber; a middle layer of cloth grid with a variable thread count depending on the grade of the tape; and an outer polythene layer that helps repel water and bond the other layers together.

The glue on the sticky side is made to stay effective for as long as possible, usually for at least 6 months, depending on the adhesive type — but it weakens after some time and may begin to peel off.

When the duct tape is in contact with a wet surface, the adhesive weakens much faster, the duct tape loses its sticky quality more quickly, and it becomes unable to seal the surface effectively. If you submerge it in water, the tape may even peel away altogether over a short period.

How Long Does Duct Tape Hold?

Duch tape can hold for several months, even a year or more. However, note that different duct tape brands can hold better than others. That’s because the polythene and adhesive materials used for the tape and the nature of the surface they hold may be different.

Also, the weather elements it’s exposed to can also affect how long the duct tape can last.

Even if you can’t predict how long your duct tape will hold for, how much the duct tape is exposed to the sun or water as a rule of thumb. If you use it on a surface that’s wet, uneven, extremely hot or cold, or exposed to UV rays from sunlight, the tape won’t likely work long-term.

You should look for a more permanent alternative specifically suited to that purpose or consult a repairs expert to have a professional job done.

How to Get the Best Water Resistance With Your Duct Tape

One of the reasons duct tape is so popular is how easily accessible it is for emergencies. For less than $20, you could get a roll of duct tape at your neighborhood store as a quick fix for almost any problem:

Choose High-Quality Duct-Tape

Yes, you’re not walking into the store intentionally looking for low-quality tape, but you may make the mistake of simply picking the most expensive brand on the rack, assuming that it equates to high quality. You shouldn’t penny-pinch either, but the price is only one of many factors you should look out for when choosing your duct tape.

These are some metrics for ensuring optimum water resistance with your duct tape:

  • Choose tape made with an adhesive gotten from natural rubber for greater strength and reliability in extreme conditions.
  • Gauge the thickness of the tape and choose one about 11 milli-inches (0.27 mm) thick to get a near-perfect balance of thickness, strength, and flexibility.
  • Choose a duct tape manufactured by co-extrusion (no lamination). Laminated tapes usually have a wrinkled texture and outer ridges that may not lay flat on surfaces for very long. In contrast, co-extruded tapes typically have a smoother finish with tiny dimples on the outside.

Clean Your Application Surface

A poorly cleaned surface will make any adhesive less effective, no matter how strong it is, so it’s important to prepare your surface by properly cleaning it before using duct tape on it. You could wipe the surface with a mixture of equal parts water and alcohol to get rid of grease and dust and leave it to dry thoroughly before applying the tape.

Use Duct Tape on a Smooth Surface

The layer of adhesive on duct tape is quite thin, so it doesn’t work very well with rough surfaces that need deep, low-point contact for proper adhesion.

If you need to attach a rough surface, you could smoothen it out by evenly abrading in circular lines. But if changing the surface isn’t an option, consider other non-tape adhesive products.

Store the Tape Properly

“Keep in a cool, dry place” isn’t just a thing hardware manufacturers write for the heck of it. Tape can be pretty reactive to storage conditions, so you really should store your duct tape at room temperature and away from moisture to keep it effective.

Use the Tape at Optimum Temperature

A temperature of about 64.4°F (a little lower than room temperature) is usually just great for getting duct tape to stick properly.

Extremely hot conditions will cause the heat to melt the adhesive, making the tape soft and ineffective, while extreme cold could make it too hard to stick. It may be difficult to get ideal temperature conditions, though, so any cool area should do just fine.

Alternatives to Duct Tape

If you need an alternative to duct tape, here are some that you could check out:

  • Waterproofing tape: It uses aluminum foil, bitumen, or butyl-based materials in the place of the polythene in duct tape to coat the opposite sides of the adhesives. It’s specifically designed to hold wet or moist surfaces, and most waterproofing tapes claim to maintain firm adhesion, even underwater. It’s not as versatile as duct tape, but it provides considerable insulation against water and air, especially in buildings.
  • Flex tape: A flexible tape made with a heavy-duty, extra-thick adhesive layer and a waterproof backing. Most flex tapes claim to be flexible enough to conform to any shape or surface and resistant enough to withstand high temperatures and UV rays from sunlight. High-quality flex tapes have strong adhesion with time and pressure. Therefore, they can work as adhesive tape for wet surfaces, even under harsh conditions.
  • Masking tape: For non-waterproof needs, masking tape is effective for temporary fixes, packing tape, or cloth tape for sealing cartons and boxes.
  • Gaffa tape: Similar to duct tape but has a higher level of heat resistance for hot conditions.


If carefully chosen and correctly applied, duct tape can fix anything that needs fixing. The dicey part, though, is getting it to hold up for as long as you need.

Standard duct tape will effectively keep water out for a while, but it’s not permanently impermeable. Duct tape isn’t waterproof; it’s water-resistant only.

That said, you should call a home repair expert or look into a more permanent do-it-yourself solution.

When buying duct tape, make sure it’s high-quality. You also want to ensure you only use duct tape on clean surfaces. Store the tape properly when not in use.

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