When the backcountry boffins first started differentiating between water-resistant and waterproof a few decades ago, many of us suspected a trick or at least an over-fussy and finicky distinction that could, for most of us, be politely ignored.
In the interim, the boffins have been exonerated, and their fussiness revealed as symptomatic of the huge strides that have been taken in outerwear technologies in recent years.
We slowly, and some of us with tails between legs (this writer included), realized that the distinction made was not only a valid one for scientific reasons but also one that was pivotal to getting our hands on the correct clothes to wear hiking.
To help you do the same, this article will bring you a short-and-sweet guide to the difference between waterproof gear and water-resistant gear.
Table of Contents
Water-Resistant Clothing
Water-resistant (aka water-repellent) fabrics do precisely as their name suggests, that is, resist H2O to lesser or greater degrees. Compared to waterproof varieties of garment, these products are less capable of preventing saturation from rainwater.
Unlike waterproof jackets, the ability of water-resistant varieties to repel moisture relies entirely on a durable waterproof repellent (DWR) coating that is applied to the outer fabric during production. This coating prevents penetration of water by a process described in more detail in our guide to DWR waterproof coatings.
In a few words, this coating (sometimes also referred to as a “lining”) causes H2O to bead up on the garment’s surface and run off before saturating the fabric.
Water-resistance definition: any fabric that relies on a coating or lining to block out H2O as opposed to a membrane.
- Offer less protection (suitable for light rain showers only)
- Generally less expensive
- Don’t have taped seams
- Treated with a DWR finish but don’t have a waterproof membrane
Ratings
DWR ratings are determined by the percentage of fabric with no H2O sticking to it following a simple spray test. For example, if the DWR rating is 80, then 80% of the fabric was dry after the spray test.
A second figure indicates the garment’s performance in the same spray test after a number of washes. For example, a rating of 90/20 tells us that the fabric maintains a 90-point rating (being 90% dry in the spray test) after 20 washes.
- 80 points/10 washes — The bare minimum for classification as DWR in most outerwear
- 80 points/20 washes — The typical DWR rating for most water-resistant garments
- 80 points/50+ — Exceptional water repellency, usually used in either very high-end waterproof products or garments which lack a waterproof membrane and rely only on DWR for resistance to H2O
As you may have guessed after so many washes you will have to reapply a DWR coating with a DWR detergent such as Nikwax.
Waterproof Clothing
Waterproof garments usually combine a DWR coating on the outer fabric, fully taped seams, and a built-in membrane lining such as those described in our article on waterproof and breathable fabric (Gore-Tex, eVent, HyVent are a few of the most popular varieties).
A waterproof-breathable membrane is an incredibly thin film or sheet of material with literally billions of microscopic holes which are too small for rainwater to penetrate but large enough for vapor molecules (from sweat) to pass through in an outward direction. This membrane assists breathability and forms a second, more impermeable barrier after the DWR outer.
- Suitable for heavier rain
- Use a waterproof fabric membrane (such as Gore-Tex, eVent, or HyVent)
- Outer layer treated with DWR (Durable Water Repellent) finish
- Taped seams for ingress protection
- Generally more expensive
Waterproof definition: any fabric that uses membrane technology that provides a minimum hydrostatic head rating of 1,500mm.
Ratings
The waterproof capacity of any garment is quantified by hydrostatic head, which is covered in more depth in our guide What is Hydrostatic Head? The legal minimum hydrostatic head rating for classification as a waterproof garment is 1,500mm, which we’ll take as a starting point for the summary below.
- 1,500mm — 5,000mm = Can deal with only very light rain and, at that, not for sustained periods. Most commonly found in jackets intended for “casual”, everyday use than in performance gear.
- 10,000mm = Suitable for light rain showers but liable to leak at pressure points where the straps of your backpack are in contact with the jacket (the shoulders, back, and belt area). Jackets with this level of water protection often focus more on breathability than on waterproofing, as exemplified by Polartec Neoshell.
- 20,000mm = Capable of dealing with heavy rain showers and seen by some manufacturers as the max waterproofing capacity required.
- 30,000mm = Garments with this rating are virtually impervious to water in even the heaviest downpours, but occasionally at a cost to breathability. This HH rating is used in jackets and rain pants for hiking in extreme conditions, such as eVent’s DV Expedition models of waterproof jacket.
Waterproof vs Water-Resistant (or Water-Repellent vs Waterproof!)
While the above treats you to a jargon-rich overview of how and to what extent both types protect you from the elements, the bottom line is this:
Water-resistant outdoor fabrics provide a level of protection that will keep you dry in lighter, short-lived showers, whereas waterproof ones are designed to prevent you getting wet in anything heavier.
So, how did you like our article on water-resistant versus waterproof and what it all means to the average outdoorsperson? If you think we missed anything important, or have any questions, please drop them in the comments box below.
