Duct tape is widely viewed as a quick fix for almost anything. There seem to be no limits as to what it can do. However, if water is involved, it seems as if duct tape may not be the best solution.
This is an odd statement if you know the history of duct tape and how it used to be called duck tape because of its ability to repel water like duck feathers. However, when it comes to duct tape, we have to differentiate between waterproof and water-resistant as well as the two different sides of the tape.
Duct tape is water-resistant, not waterproof. The adhesive layer is particularly susceptible to moisture, losing its tackiness and lifting. However, over time, water can also penetrate the back of the tape. As a temporary solution, duct tape can be used, but it is not an ideal permanent solution.
Difference Between Waterproof and Water Resistant
Whether something is waterproof or water-resistant depends entirely on how effective the product is at repelling water.
Waterproof products are sealed against the infiltration of water. The barrier between the product and the water outside of it keeps water from soaking into the product.
For example, a wooden boat would have to have a waterproofing coat on it to prevent water from soaking into the wood’s cavities and weakening the wood.
Water resistance, on the other hand, means that the surface is sealed against the effects of water, but only to a certain point. After enough time has passed, the seal can be broken, and water can infiltrate the item.
Duct Tape Is Water Resistant
Although duct tape can be somewhat effective in situations that involve water, it is not fully waterproof; it is water-resistant.
The makeup of duct tape is what allows it to be water resistant but not waterproof.
The mesh fabric with a polyethylene plastic coat is what makes duct tape water-resistant. This plastic-like coating makes the outside of duct tape suitable for environments with water.
However, the inner, sticky layer of duct tape containing glue is what makes the duct tape vulnerable to water infiltration.
As the glue is exposed to water, as is the case with many types of glues that aren’t as solid as superglue, the glue begins to lose its staying power and will peel away from whatever surface it was supposed to adhere to.
The mesh fabric coated with polyethylene provides a near-waterproof effect, but the sticky side with the glue prevents the duct tape from being fully waterproof.
What Excessive Water Exposure Can Do to Duct Tape
Since water-resistant items eventually fail with enough water exposure or with enough exposure time, duct tape cannot remain attached for long when in moist environments or when immersed in water.
When the layer of duct tape with glue is exposed to water, it will weaken and detach from the surface it was attached to.
Even the polyethylene layer is not perfectly protected from water. With enough time in the water and enough water pressure, water can begin to leak through the plastic-y layer.
Whether the tape begins to fall off or water starts to seep through it, duct tape is bound to fail with enough water exposure.
This makes duct tape a good temporary solution when working with water, but it is very important to note that the duct tape will fail somewhat soon after application.
Appropriate Water-Related Uses for Duct Tape
Although duct tape is not the best long-term solution, it can be a great short-term solution to minimize damage to your home.
For example, duct tape can be used to cover a gap or holes in plumbing that has formed and through which water is pouring.
Rather than leaving the opening uncovered while looking for a more permanent solution, since many homes have readily-available duct tape, it would be wise to grab the nearest roll to cover the hole for a short time.
Leaving this opening in your plumbing uncovered while looking for a more permanent solution can cause water to pool, which can damage flooring, wood products, and electronics.
It is important to know that a big enough hole in the plumbing would cause high-velocity water to come rushing out of the opening. With this much water pressure and large amounts of water, the duct tape is not likely to hold long.
However, if the leak is small enough, the duct tape would be able to hold long enough for a more permanent solution to come to mind and be done, whether it’s by you or a plumber.
Additionally, duct tape repairs outside can be done, but they would have to be short-term solutions unless you live in an area that gets very little rainfall.
Let’s say that your patio umbrella breaks in a storm. It is not completely broken in half, but it is splintering, and needs repairs before the next storm fully breaks it.
A few layers of duct tape can keep it upright and somewhat stable until you are able to replace the entire umbrella or replace the wood of the umbrella.
If it rains, though, the duct tape is likely to lose its strength and fail.
When Duct Tape Should Not Be Used
Duct tape can be ideal for short-term fixes and emergency situations, but it absolutely should not be used for fixes that are meant to be permanent.
Plumbing leaks, especially large ones, should be fixed as soon as possible since the tape may not last more than a few hours.
In the case of an outdoor fix, the item should be permanently fixed as soon as possible since, as soon as rain comes through, the duct tape will not hold.
Additionally, duct tape should absolutely not be used for waterproofing since the tape is water-resistant, not waterproof.
Whether the waterproof tape is used indoors or outdoors, duct tape will not do the job.
If the desired effect is to prevent water from entering an area, whether the area being waterproofed is the roof, bathroom, attic, or kitchen, duct tape cannot prevent water from infiltrating an area for very long.
Waterproofing a boat with duct tape is an especially bad idea since a boat can sink if waterproofing is done incorrectly.
A hole in a boat that is sealed with duct tape will not be free of water for long, and the interior of the boat will experience an infiltration of water.
Duct tape can even fail due to the condensation on HVAC or dryer ducts, which is one of the reasons why it should never be used on ducts.
The way that duct tape behaves when exposed to moisture is actually one of the reasons why it is inappropriate for use on packaging and why it should never be used for vapor barriers.
What Kind of Tape Is Waterproof?
Waterproofing can be done with a variety of substances, including waterproofing membranes, but tapes can do the job as well.
Two great types of tape for waterproofing are silicone rubber tape (amazon link) and butyl tape (amazon link).
Silicone rubber tape creates a permanent bond to whatever it is applied to. It is made of cured rubber and its adhesive is very strong, making the tape waterproof rather than water-resistant.
However, silicone rubber tape can take up to 24 hours to dry. This tape is a good long-term fix but certainly not a quick one.
Butyl tape is also based in rubber, making it similar to silicone rubber tape. It also creates a permanent bond but the bond dries almost instantly, unlike silicone rubber tape.
Sources
https://waterprooftips.com/is-duct-tape-waterproof/
https://www.bobvila.com/articles/water-resistant-vs-waterproof/