Condensation using tarp

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XRV John

Nomad
Jan 23, 2015
256
26
Scunthorpe
Spent Sunday night out under tarp in my back garden. Went into the hammock about 9.30pm and the underside was already damp which I presumed was condensation as the air was moist and the temperature had dropped to low single figures (4 degrees or so)

When I woke up there was moisture on the bug net which I presumed had dripped off the underneath of the tarp

I live in Scunthorpe, North Lincolnshire. The tarp was a DD 4x4 set up like a tent so the sides were just off the floor 2" to 6" and the ends were brought in to make doors with a small gap about 4"

So what should I be doing to avoid condensation or is it, like rust on my motorcycles and engineering machines, a demon that can only be kept at bay for a while?

Thanks for any advice

John
 

bopdude

Full Member
Feb 19, 2013
3,000
215
58
Stockton on Tees
Just my thought, if you had in tent mode was there airflow, you say there was a gap under the tarp but what about at the top, top of the doors ?
 

XRV John

Nomad
Jan 23, 2015
256
26
Scunthorpe
Thanks

There was hardly any wind at all. The tarp never whipped or rippled. Very still all night. The door gap narrowed towards the top
 
Apr 8, 2009
1,165
144
Ashdown Forest
Its just one of those things that you have to put up with to be honest. Having the tarp in tent configuration will exacerbate it, but even pitching your tarp as a floating type set up with good airflow all round will still condensate when there is plenty of moisture in the air and little breeze. Its not usually a serious problem, just more of an annoyance really...
 

scarfell

Forager
Oct 4, 2016
224
2
south east
The best way i've found is to ensure a fire keeps the inside warm at all times, i use the lean-to type setup for most nights in the cold, with a bit extra length dropping down at the top to help keep a nice pocket of warm air inside, and a long burning fire (fire proofed your kit recently?)


Condensation will always form unless you either have air-flow (think how fast you need car fan on to get rid of a tiny layer on windows! Ie a gale), or heat - the alternative is to create barriers so it doesnt get to your skin (think inner tents, hammock underquilts, doubling your carry load!)

Remember to use Drip lines with your guides and hammock straps etc
 
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Nohoval_Turrets

Full Member
Sep 28, 2004
348
10
52
Ireland
In still conditions water will condense on any cold surface - there's no getting around that. You have a few options:

1. Ventilation: in stiller conditions, choose a more open setup.
2. Site selection: in really still conditions, choose a more exposed spot
3. Heat: light a fire
4. Live with it

Option 4 is usually what I end up doing. When using a tarp I generally use a bivvy bag too, so that dew and dripping condensation doesn't get onto the sleeping bag. And make sure your gear is tidied away into bags.

A bit of condensation is not a problem until wind suddenly picks up, dislodges the condensation, and it's raining under the tarp. I sometimes use a rag to wipe down the tarp when that happens.

In any event, there's only so much condensation that CAN build up, and really it's not a lot of water, and once you're used to it and expect it, it's not a problem.
 

GGTBod

Bushcrafter (boy, I've got a lot to say!)
Mar 28, 2014
3,209
26
1
I'd say the same as all have mentioned the lack of airflow, same as when inside a bivvi most of the internal moisture comes from our breath, with the bivvi you beat it by breathing in and out of the hole if you breathe out inside the bivvi it is not long before you are soaked, with the tarp it is about airflow. You mustave been snug and well sealed from the breeze as i have never managed to get moisture like you've described, you just described my shelter I used for the 3 weeks i just spent in the Adirondack mountains where i had temps from 90f down to 24f (32f is 0c), even when the sides of my tarp got snowed onto the ground i didn't wake to condensation like that, i did have my ends open more than you describe

IMG_20161027_170053.jpg
 
Jul 30, 2012
3,570
224
westmidlands
If it was condensation because of your breath, another tarp will protect that tarp from the cold and thus you get no condensation on the inner tarp, you can reduce condensation on a tent by a great deal by slinging a tarp across it. When it rains (or heavy dew) the material gets cold and when your breath hits it instant condensation( its how 2 skinned tents are supposed to work, but dont).
 

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