Condensation occurs because the atmosphere inside your shelter is hotter and more humid than it is outside your tarp. It has been the bane of many a camper and hiker. Accordingly, there are a lot of tips to get rid of it, some of them even bordering on superstition. However, some tips are always the same, because they work.
You can never completely stop condensation under a tarp, or any form of shelter for that matter. But, you can bring it to a minimum and reduce it so it doesn’t bother you at all. You’ll need a well-ventilated shelter set up, some form of ground cover, as well as a waterproof tarp.
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Ensure Airflow and Ventilation
Proper ventilation is crucial for preventing condensation under your tarp. In fact, it is so important that without it, the rest of the tips we have here are not likely to work. While some people like tent camping in windy conditions, I always prefer to have my tarp and hammock wherever I go. However, it doesn’t matter whether you have a tunnel tent, a tarp, or an improvised woodland shelter, the rule stays the same – you must have proper ventilation, or there will always be condensation under your shelter.
You should also utilize any wind you may have where you’re camping. Set up your shelter so that the wind can run through it. Do not set it up like a sail to gather wind, because that is the best way to get your tarp blown off. The openings should be larger than three inches and should be on opposite sides of your shelter. This will allow the air to circulate through your tarp setup and reduce the condensation under that tarp.
Air Out Your Shelter Whenever You Can
Another thing that will help you reduce condensation under your tarp is airing out your shelter. When you’re not inside, open the sides of your shelter and let the air run through it. This will not only help to dry out your tarp from any excess moisture but it will also allow you to practice various tarp setups.
Additionally, if you’re camping in a sunny environment, you can dry your tarp in the sunlight, anywhere you can find it. Just make sure you spread the tarp out carefully and secure it by tying the corners off. You can use rocks or branches to secure the edges, but they usually just bring more moisture into the mix.
Airing your tarp or tent is especially important when camping in high humidity where there is an increased chance of condensation in your shelter. If you’re in a rainy environment, make sure you air your shelter any chance you get, even if it means doing it a couple of times a day.
Lift Your Sleeping Arrangement off the Ground
Not sleeping directly on the ground might not help against condensation, but it will reduce its effect on you. By placing your sleeping bag on a bed of logs you’ll prevent any condensation that’s running down the inside of your shelter from soaking your sleeping bag.
If you cannot find or source logs to make your bed, even a groundsheet will do. You just need to insert another layer between you and the ground. If you’re using a groundsheet, make sure you fold the edges away from the sides of the shelter. This way any condensation that is running down won’t fall on your groundsheet, but go under it.
Light a Fire in Front of Your Shelter
While you need a specific setup to light a fire under a tarp without causing any condensation, you can place your firepit in front of your tarp setup. This will keep you warm and dry out any condensation that may occur during nighttime.
A fire in front of your shelter is a double-edged sword, though. A fire can also make things worse if your tarp setup doesn’t have proper ventilation. If all the heat from the fire enters your shelter and can’t leave, it will only create more condensation. No matter the shelter you have, be it a tarp, a tent, or a shelter made of wood, condensation will occur.
When lighting a fire to keep yourself warm and reduce condensation, ensure your shelter has enough airflow to prevent the heat from building up. The more heat there is, the more condensation you will find in the morning.
Pay Attention to How You Store Food and Water
In addition to body heat and breath, food and water are the most common causes of condensation, even in the best shelter setups. While we can’t see it since it happens so slowly it is invisible, but our edibles are always releasing some particles. While these releases won’t bother you in everyday life, they can get quite bothersome within an outdoor shelter.
Since most tarps are made from waterproof materials which prevent water from getting in, but also prevent air from getting out, all of the particulates, breath, and body heat are caught on the sides of the tarp. Thus, even a small cup of water can condensate under a non-breathable shelter setup.
How can you prevent this from happening? The answer is pretty simple. Do not eat or drink in the shelter. Do not store improperly packaged foods in the shelter. By avoiding these things, you can reduce the condensation under your tarp by 50%.
Keep Green Plants Out of Your Shelter
Plants can be extremely useful when building a shelter. They can provide building materials, insulation and even turn insects away from your woodland abode. You’ll need to utilize them carefully, though, because they can create more of a problem than a solution.
This is because reen plants and leaves have a lot of water in them. This makes them give out more vapor and, in turn, create more condensation under your tarp. So, keep plants in front of your shelter or, if you’re using them for insulation, keep them under a groundsheet.
In addition to this, you should dry any wood you plan to use inside your shelter before placing it under your tarp. Even fallen trees and branches can hold a lot of water in them. This will only create more condensation once the temperature drops outside.
You can dry the wood you’re planning to use to lift your sleeping arrangement off the ground, by placing it near a fire, but not in it. Hold the logs at least 2 inches away from the fire and let them slowly dry. Once dried they will make a clunk sound when hit against other pieces of wood. The sound will be resonant, not muted if the wood is completely dried.
Keep in mind that this technique doesn’t work with all types of trees and that it should only be used as a reference to ensure the wood is dry. You should use all of your senses to draw conclusions when in the wild.
Tilt the Tarp to Have Safe Runoff
Outside humidity can increase condensation under your tarp, especially when improperly handled.
The best way to ensure none of the outside water comes into your shelter and provokes additional condensation is to set up your tarp at a sharp angle. A pointy tarp setup will allow the water to run off your tarp and onto the ground, away from you.
If you don’t mind, you can make an asymmetrical shelter from your tarp to ensure both the rain outside and the condensation inside drip down in the same direction, which should be away from your sleeping bag. Just make a shelter that’s tilted on one side and open on the side opposite it. Make sure the open side is not facing the wind, you wouldn’t want your tarp to become a sail.
These setups will only work with waterproof tarps. A regular tarp is highly water-resistant, but it will still let some of the liquid seep in. This would result in even more condensation inside your shelter. So, get a waterproof tarp before setting off on your adventure. If you don’t have a waterproof tarp, you can make your tarp waterproof a couple of days before you set off on your trip.
Don’t Be Afraid to Experiment With Different Shelter Setups
Finally, if one type of shelter doesn’t work, don’t hesitate to try out a new one. Remember that your gear is there to serve you, not the other way around, and while it is necessary to respect your equipment, it should not completely determine your entire outdoor experience.
For me, personally, a tarp works best when it provides shelter for a hammock. I’ve set up my tarp between trees in an inverted V shape to complement my hammock. The sides of the tarp never touch the ground to improve airflow. Not only was there no condensation but I was also toasty warm in my hammock.
Now, my setup might not work for everyone, and that is perfectly fine. You should try different tarp setups and decide which one works best in the conditions you find yourself in.