Trying to find the right WP material for poncho

silnylon … I heard that it isn’t completely leakproof
Where did you hear that?
Anyhow, it’s wrong, with good silnylon.
Mind you, you CAN get condensation on the inside in cold wet weather, but that happens with ANY fabric.

Cheers

Ripstop by the Roll has a few different, highly waterproof fabrics, both polyester and nylon based fabrics. The ones labeled with PU4000 on the end, are in particular highly waterproof and durably so. Their new “Mountain” silnylon also rates pretty well according to their spec.

The Neoshell would make for a heavy, but comfortable poncho.  For myself though, I find most heat and moisture build up in the upper chest area–otherwise a poncho is well ventilated enough to get rid of a lot of both.

I’ve used a combo of breathable, silicone treated nylon with Tyvek 1443R to good effect, as a low cost, WPB poncho which doesn’t require DWR re treatments.

A 4oz fabric will make for a very heavy poncho, and neoshell would make for a very expensive one.

The 40d PU4000 from RSBTR has a very nice hand and is maybe a bit quieter then some if you are looking for something a bit different then silnylon, which is always a great poncho choice. If you want soft/quiet/breathable I think you will have a hard time making something that competes with a frogg toggs poncho on a cost/performance scale.

“If you want soft/quiet/breathable I think you will have a hard time making something that competes with a frogg toggs poncho on a cost/performance scale.”

Very breathable, uncoated 1.1 oz ripstop nylon can be found at DIY gear supply and other places for pretty inexpensive.  At the former place, for 4.95 per yd. Putting a medium thick coating of silicone on that adds a truly durable water repellency and increases the HH some.

“Soft, Kite” 1443R Tyvek is also fairly inexpensive and fairly light weight.  When you sew the two together, with the siliconized nylon on the outer and Tyvek on the inner, you get an effectively waterproof and breathable composite that doesn’t require DWR reapplication.

You only need that for the front.  For the back of the poncho, you can use an UL, waterproof fabric.

Speaking from experience of making and using something very similar to the above, it works very well and is world’s more durable than a Frogg Toggs poncho. And if you do the DIY silicone coating right, it will also be significantly more breathable than Frogg Toggs fabric.

https://backpackinglight.com/forums/topic/oddunique-but-very-breathable-rain-gear-system/