The short answer is that no, unfortunately, nylon is not waterproof. It is a fabric that will naturally absorb water and once it is soaked through, it will allow water to seep through it.
Certain manufacturing aspects of nylon can make it more water-resistant.
Additionally, nylon is a great base for many water-resistant products. When you see a nylon backpack or jacket that claims it is waterproof, that is because it has been treated or coated with something else to make it waterproof.
Waterproof versus Water Resistant
A completely waterproof fabric implies that water does not go through them to the opposite side at all.
Water-resistant means that a fabric will stop the water from passing through it up to a certain point.
Generally speaking, this difference does not mean anything to the average consumer. However, people who spend a lot of time outdoors, whether for work or for leisure, do care about the difference.
Nylon’s Water Resistance
Nylon can be made more water-resistant by the manufacturer tightening the weaves of the fabric or increasing the weight of the nylon. This is how ballistic nylon is made. But while this will reduce the amount of water that can pass through nylon, it will not completely eliminate it.
Nylon is more water resistant than, say, cotton. However, extreme weather conditions will cause water to eventually seep through. Additionally, any seam will invite water to creep through as well.
Nylon can be treated with substances to make it waterproof. These coatings will make the water bead on the surface instead of passing through. Examples of such coatings are:
These materials are finishes that are added to nylon to make it waterproof. Sometimes, nylon is even laminated to a water-resistant coating.
Making nylon, or any fabric for that matter, completely waterproof is an expensive process. Many products will claim they are waterproof but are not because they are too cheap to have actually been made waterproof properly.
One big weakness that creates problems with water-resistance is sewing. If a product is stitched together, that will lower the waterproofing rating because the stitching creates holes in the fabric. For fabric to maintain a high waterproof rating, it must be welded ultrasonically.
This type of welding is very expensive, and would drive up the cost of the product. Many manufacturers do not want to bother with such techniques in order to keep the prices of their products down.
Most manufacturers know that the average consumer is not going to be swimming with their backpack or jacket, so they do not put the material to the maximum amount of testing.
DIY Waterproofing Nylon
You can purchase waterproofing sprays and solutions to add to your nylon jackets and backpacks. You should not do this to a brand new jacket to avoid ruining a waterproofing coating that is already there.
However, if over time you notice that your nylon jacket is letting in more water than it used to, it may be time to re-waterproof it.
Most sports stores, some shoe stores, and online retailers such as Amazon will sell waterproofing sprays and solutions. Be sure to check that the solution or spray you are buying will work on nylon. Some sprays are specialty made for different fabrics. Ideally you get one made for nylon.
The process looks something like this:
- Ensure the jacket’s colors will not bleed when you apply the spray, so check a small area first.
- Wash your jacket and put it in an additional rinse cycle to remove any traces of soap residue.
- In a well-ventilated area, preferably outside, spray the jacket with the waterproofing spray. Additionally, make sure you are not doing this on a windy day if you are applying the spray outside.
- Spray in even strokes, paying extra attention to the seams. Coat until entire jacket is covered and wet.
- Let the jacket dry until damp.
- Apply heat to finish drying the rest of the way. Some waterproofing sprays do not require this step, so if the jacket’s care instructions say to avoid putting it into the dryer, you may skip this step. However, if the jacket can go into the dryer, applying some heat to finalize the waterproofing process is ideal. Alternatively, you can use a hair dryer.
- Second coats can provide more protection but are not necessary.
- A warning: if you have respiratory problems, you should wear a mask for this process.
Nylon Versus Polyester
Nylon and polyester are often grouped together when it comes to these sorts of questions because nylon and polyester are synthetic fabrics crafted from petroleum and crude oil residue.
Polyester is a hydrophobic, meaning that it will repel water. It does this because the fabric is rough. However, enough water will eventually overcome this aspect and the polyester will also get wet. It does dry faster than nylon however.
However, polyester does not repel oils, which is an important consideration when thinking about work out clothing. Whereas oils that cause body odor will wash out of nylon in the washing machine, they will not wash out of polyester.
Is Nylon Good for Rainy Climates?
Nylon is water-resistant enough to keep you mostly dry as you walk through gentle rain or seek shelter from a heavier storm.
Is Nylon Breathable?
Because nylon is a synthetic fabric, it is not breathable. Over time, nylon will trap sweat against the skin, rather than expelling it. However, this can work in your favor in warmer climates because nylon will help keep you cool.
How does Nylon Hold up in Winter?
Nylon is usually used as an outermost layer in the winter because of its water-resistant capabilities. This works in a warmer winter, even if it wetter. However, if the winter is also cold, especially cold and wet, you will want something sturdier than nylon.
Is Any Fabric Waterproof?
Gore-tex is waterproof. Other fabrics can be made waterproof with proper treatment, regardless of whether they are synthetic or natural.