Condensation...tent vs. tarp

“Don't know where, but I remember reading where someone wrote where tarps don't gather condensation like tents do.

If that ain't a pound of bologne, I don't know what is?

My Trekker Tarp has formed condensation every time it has been moist out. Last fall, at Old Logger's Path, I woke up with ice in the underside of my tarp. I had it pitched as close to the ground as I could, but as RichB can attest, it was pretty blustery the first night, and it still ventilated.

And this weekend, it was 34F and raining/snowing drizzley wet snow on Fri night (had my awning up the whole night) and there was still lots of condensation on the underside. Sat night, with temps in the 20s, it only snowed, but there was still moisture on the underside.

Tarps ventilate well and don't gather condensation...my butt!”

“We had that problem with ours once. It was pitched really close to the ground. Since then we pitch it about 8 inches off the ground and haven't had a problem. BUT we haven't been out with it as much as you have most likely. I think we've used it in cold weather maybe three times but we only bought it last year. It sure was miserable when it happened! Dripped all over us and we awoke wet and cold.”

“Well, if condensation can form on the ground in the form of dew, I would reckon it could form on a tarp as well. Why not? The ground is about as well ventilated as you can get.”

“Don't ask me-
my Seal of Approval from the American Meteorlogical Society was revoked last year.”

“Condensation and frost can form on any service regardless of how much ventilation is provided. When the air temperature falls the air?s ability to hold moisture is reduced. That is why relative humidity can go up without a change in the amount of water in the air, just a temperature drop. Water in the saturated or near saturated air will condense on anything and ventilation will not help. Venting in a tent helps when it is dryer outside than inside. Because we humans give off moisture from our skin and in our breath there is usually more moisture in the air inside the tent than in the outside air. But if the outside air is not dryer the ventilation is irrelevant. It is the weather not the ventilation.”

“Hmmmmmm...damn condensation nucleii!”

“I agree with lost in Idaho. Sometimes it's just so damp out no amount of ventilation matters much. A example is rime ice which is like a frozen fog that occurs in the mountains in high humidity and adhers to everything.
The first night on the Old Loggers Path my tent and fly was completely dry in the morning since it was windy and tent I was in has a fabric almost like mesh. On the second night with little wind, moisture had condensed on the fly only.
Buddur, I remember on the first night when you set up the tarp it was flush to the ground and the edges were sealed up with leaves. Maybe that combined with the dog inside too made it clammy.”

“Your gonna have condensation anyway. Deal with it cause you can't win.
I've had it on top of my sleeping bag around the opening while in a 3 sided shelter. I've also had it on the tarp above my head too.”