Question:
Can you provide a comparison table for different types of waterproof materials e.g. Gore-Tex Paclite, Gore-Tex XCR and eVent fabrics
What are the merits of each? Is XCR being replaced? Answer:
Hi there,
Gear here, Richard 'Perennial Breathability Questions' Gear,
master of moisture vapour transfer. I can't produce a definitive
table of relative performance for different waterproof fabrics, but I
can give you a quick run down of the pros and cons of each of the
materials you mention.
Why no breathability figures? In simple terms the lab tests to
measure breathability are a bit of a can of worms and some fabrics
seem to be intrinsically favoured over others. Additionally remember
that venting provisions and intelligent garment use are just as
important as the fabric used.
First, Gore-Tex Paclite is designed as an ultra-lightweight fabric
for packable emergency waterproof use. It's light, it's thin, but
it's also relatively fragile and because it's so thin, wets out
easily and stops breathing effectively. Best for fast and light use.
Not good for backpacking or anything abrasive.
Gore-Tex XCR has already been replaced with the new Pro Shell
fabric. Pro Shell uses a similar membrane to XCR but a lighter,
smoother, tougher woven backer instead of the old knitted one. Pro
Shell can be made almost as light as Paclite - so what's Paclite for
now? - but is significantly more durable. It also slides very easily
over under layers making it feel very comfortable and mobile in
use.
Side by side, Pro Shell left and XCR right. The
new woven inner is
lighter, more breathable and slides more easily over inner
layers.
In tests it's also proven far more durable and resistant to
abrasion.
Breathability is okay, but if you run hot, you may well find it
lacking. Pro Shell, like other Gore-Tex waterproof fabrics, has a
very thin layer of PU to protect its PTFE membrane from contamination
and this reduces breathability compared to a pure PTFE membrane.
The eVent fabrics are genuinely vapour permeable because the
protective film is on the inside of the pores leaving them free to
breathe. That means it's apreciable more breathable than Gore's
waterproof fabrics and, we'd estimate, around the same level of
breathability as Gore's windproof Windstopper material. The weight of
eVent fabrics depends on which face and backer is used with the
membrane - there's no eVent fabric as light as Paclite, but it comes
close to Pro Shell's lighter incarnations.
Which should you choose? If you run hot and tend to get damp, I'd
suggest eVent as the most breathable option. If that's not an issue
for you, Gore-Tex Pro Shell is light, tough and comfortable to wear.
Paclite? Only if weight and bulk are your over-riding concerns.
There are plenty of other options out there, but you didn't ask
about those ;-)
Happy tabulation
Yours breathably
Richard G
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