Hydrostatic Head rating not enough, or something else?

[Bike-N-Hike]

If I understand correctly you would have to exceed approximately 59 inches of water column if we are talking H20. Water shouldn't be coming thru.

Your Tarps Ok.

You could test it by filling your tarp with water and checking it's permeability to whatever you manage to trap.

[ocnlogan]

Thanks for all the replies everyone, that helps set my mind at ease.

As I said, this was my first experience with a Sil-impregnated fabric. So I wasn't sure if this is how it wet through, or if it was just condensation.

And I've love to do a backyard test. In fact, I'd love to have a backyard (housing prices are absurd where I live at the moment, so I'm stuck in an apartment), but thats why I was testing when I was, as it was the closest thing I could get to "backyard".

Thanks again .

[DrPhun]

It doesn't take much humidity to create condensation at 35degrees.

[Just Bill]

Yar- best way I've heard it explained-

"You don't need to be in a glass of ice water for it to develop condensation do you?"

It's simply a cooler surface than the surrounding air that allows condensation to collect.
A tarp with wind blowing over both sides- especially a wet one- would be cooler than the surrounding air.

If anything- when using less than 2000HH- the best trick I know is to pitch it with shock cords or a hair loose. The slight slack in the tarp allows a good bit of the force of falling rain to dissipate.
In addition- being fabric- if you pull it razor tight- you are ever so slightly opening up the weave of the fabric and over time- prematurely wearing/weakening the coating.

[Chloee]

Hydrostatic Head, it is useful when choosing a tent!

[old4hats]

Pretty normal I think, I have had the same issue with my silnylon, simpoly, and cuben tarps.

[BigE94]

Condensation is pretty common for any tarp, in my experience. I've experienced condensation with silnylon, polyester and cuben fiber tarps.

Yep condensation as SilverSurfr said. As a matter of fact he gave me the same answer when I asked about my PU4000 tarp being wet underneath. I was a little wet behind the ears. PU4000 has a crazy high HH and in my opinion not worth the extra weight, but I have it and it works well.

[BillyBob58]

Thanks for the help so far guys .

While I've hammock camped a fair bit over the last year or so, most of it hasn't been in much rain (big droughts around here most of the year). Additionally, this is my first sil-tarp. My other tarp is a Kelty Noah 12, which is PU coated. I wasn't sure if Sil-coated fabrics worked a bit differently than PU stuff, or if I had simply leaked through.

The rain was intermittent through the day and evening. The rain that did fall usually didn't last more than 30 minutes, and and was mostly straight down. Daytime highs of ~55-60f, with lows that night of ~35f. I setup the tarp and hammock at the top of the hill, around 10am, and used it for lounging/relaxing during the day, and then decided to sleep in it overnight (I was at my families cabin, and elected to try out my setup just outside, to try my new TQ, tarp, etc, so then I could bail if anything bad happened). During the day I did not notice any water on the underside of the fabric.

I got into the hammock around midnight, after chatting inside to family during the reunion, so the temperature was already low, and the water on the underside of the tarp was already present before I even got in, and started generating my own condensation.

So its pretty common for the inside surface of the tarp to be that damp then?................

Yes. Exceedingly common, especially (in my experience) in a grassy and exposed back yard. IOW, I have had far less of this in the actual woods than my back yard. But in my back yard, with an unoccupied hammock hung from a stand, and with an UQ attached and a TQ inside of it, and no rain or snow, I have more than once gone out to bed to find the underside of the tarp soaked. And when it is cold, a thick layer of frost over the tarp, UQ and maybe also over the TQ. All with no contribution from my body's moisture output. I suspect this ( water drops or frost) has been much worse in cold weather, but I can't remember for sure if there has been much difference.

But again, in the woods, hanging over forest duff, and usually sheltered much better by multiple surrounding trees, even during rain or snow, I have found this to be much less of an issue. Although, if it is cold I am probably going to get significant condensation of my breath and body vapor on the tarp, and maybe some condensation down below. Unless maybe I am in vapor barrier clothing and using a frost bib.