Testing Páramo Analogy Waterproof Clothing: How Well Does It Work for Rain (and Wind Shells)?

[Benjamin K]

I’m using a Páramo Velez jacket in winter. It’s a good warmth from 10 C to -20c. I’ve goten wet  with it on a bike ride in heavy rain but mostly around the zippers.
I don’t use it much for backpacking but for cool/ cold overnighters it’s very comfortable. Works best if you stoll procduce warmth and dry it out.

I remember sitting on my pull in wet snow/ cold rain around freezing and feeling ok warm with a thick fleece under. better than pulling out the puffy and getting that wet.
in ski touring I use a Buffalo pile pertex garment which combines very well around freezing and under.
Two separat garments woul be more flexible and finding a good wind shirt and fleece, maybe Alfa, should be comparable. That’s what I use in summer. And a WPB shell.

[ZY]

Great work!
1. How does this jacket compare in MVTR to a Polartec layer combined with a Shakedry shell?
2. I recall a forum discussion mentioning that aged Shakedry jackets, while still repelling water on the surface, tend to develop a damp inner lining. This study made me wonder: could applying a DWR treatment to the inner surface of an aged Shakedry shell help restore its performance?

[Stephen Seeber]

Hi ZY.  Thanks for reading. I took a brief look at your first question here.  I used two combinations of off-the-shelf “jackets” placed under a Shake Dry jacket. RAB made Alpha Flash. It used  120 GSM Alpha Direct.  I use mine all the time around the house. The Patagonia Nano Air has gone through a number of iterations.  The one I used, perhaps circa early 2020s, has Air Permeability of 41 CFM/Ft2.  I don’t use it any more, since a high MVTR shell with good ventilation and an appropriate Alpha Direct layer is more versatile.   Here are the results.

So, the Paramo jacket actually performs better than the “combo” tests.  This result might change with an Alpha Direct 60 gsm shirt, but you raise a very good point!  The MVTR comparison with other garments probably should be based on “like” layering structures. The Paramo jacket liner has air permeability of 289 CFM/Ft2. This is higher than a lot of base layers. In contrast, the Alpha Flash air permeability is 626 CFM/Ft2. So, the answer here is unclear but perhaps worth a closer look.  It wouldn’t surprise me if the MVTR of the test jacket is higher than the Shake Dry. Also, bear in mind, that I have no idea how the membrane and pump liner in my jacket compare with current models.  I have never seen a current model.

Regarding your second question.  My experience with Shake Dry as it ages is that it develops tiny holes in the membrane and eventually permits some water penetration.  I rarely had moisture accumulate on the inner surface, but I had pit zips installed on all of mine to avoid that problem. I think if you experience moisture accumulation on the interior you are sweating too much and have overwhelmed the MVTR of the material. If you coat it with DWR under those conditions, I expect vapor would condense in the jacket and eventually drip down the fabric.  So, I don’t think you would accomplish much.  I have put away my Shake Dry jackets. I will use them in the winter, mainly as a wind layer.  However, I have replaced Shake Dry with the Fine Track Photon, for which I published a review here.

 

[Stephen Seeber]

Small correction.  Above, I stated that it wouldn’t surprise me if the MVTR of the test jacket is higher than that of the Shake Dry.  That statement applies only to the outer shell of the test jacket.  Not the combination of the two layers, which is what I tested.

[Max R]

Hi Stephen, outstanding article as always. Thank you for shedding light on the “lab” hydrostatic head test vs the “real world” shower test. IR imaging, wow! Hats off to you.

Do the findings of this test imply that a single-layer nylon weave with gaps around the same size (~35nm), paired with a hydrophobic mesh/loft (like alpha direct as you commented above) is a sufficient “cool rain” clothing system? Seems like the pump liner might as well be standalone, since both layers are treated with Nikwax and meant to be hydrophobic? A base + octa/alpha + single-layer nylon weave?

Separately, I recently purchased a discounted Rab Phantom CNDR and it’s a 7d, 2.5 layer Pertex. Though I still lean toward packing my heavier old north face rain jacket / Frogg Togg poncho due to the mechanical ventilation. Hard to live without that.

[Stephen Seeber]

Hi Max: Thanks for reading and your kind words.  First, the shell is polyester, not nylon. My mistake.  Second, to your second paragraph, I think that is right. Third, I looked up the jacket.  It has very poor MVTR, assuming they are using the JIS L 1099 b1 test method.  You are definitely going to want mechanical ventilation with that jacket.  I wonder why so many brands, if they list test numbers, list 20K HH and 20K MVTR?  What are the odds they will both come out the same during testing? Vanishing, I would say.  Now, 20K for HH is great (although possibly unnecessary).  On the other hand, 20K MVTR  is miserable.  But kudos to Rab for listing something. You will have a pretty good idea of what you are buying.

[ZY]

Thank you for the detailed and insightful response! It’s very helpful.

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