Your comfort and safety are secured by a properly set shelter, and in most cases that will be your tent. Similar to rainjackets, other than allowing you to feel safe, tents primarily have the purpose of keeping you dry. But, how do you remove waterproofing from a tent?

There are many reasons why you might have raindrops collected somewhere in your tent, but if it turns out that the tent material itself is absorbing water, it means that the waterproof coating is torn. To re-apply for waterproof coating, you will need to know how to remove the old coating from the tent. Put it in the washing machine and grab a powder detergent!

Is It Time to Re-Waterproof My Tent?

The easiest way to keep your head dry during a camping trip is to have a secure, waterproof tent. It is important to take good care of it so it can be used for the years to come. Waterproofing coating breaks down when dirt and oil are smashed into the fabric. Because of that, wash and dry a tent after each use.

First, identify the problem if you have water coming in the tent, sometimes the waterproof coating might be still efficient and present on the fabric. Here is a list of other potential things you might want to check out:

  • Setting up is important, and if a ground tarp is stuck underneath the tent water can be collected there.
  • Double-wall tents require proper staking, otherwise, the fly can stick to the tent of the body and allow water to run in.
  • Used-up zippers can often be the breaking point where the water is coming in the tent, you should learn how to waterproof them as well.

Now, in case you are certain that the tent is properly set, and you have visited some harsher terrains that are dusty and rocky, it is time to plan out cleaning.

How Waterproof Is Your Tent?

How to remove waterproofing from your tent

If the tent is made of polyester material, then you will see it as part of the “hydrostatic head” measuring tent specifications, usually listed in millimeters. In essence, it is a measure of how water-resistant the fabric of the tent is.

If the specification says that your tent has a hydrostatic head of 4000 mm, it means that the tent fabric could hold a water column 4000 mm high before the water pressure started to push water through the fabric. The larger the number, the more water-resistant the tent is and the more rain and time it can withstand before it leaks.

Cloth tents usually do not have a hydrostatic head measurement, because the way the linen fabric becomes waterproof is different. Of course, the fabric is not the only source of water resistance, it is also important that your tent has good seams, seals, and teeth because all parts of the tent are potential spaces for water to enter.

Waterproofing Red Light

Knowing when it is time to clean the tent from the old coating is crucial for its maintenance. The red flag symptom is when you notice the fabric is sticky. This can cause trouble while setting up because the panels are more difficult to pull apart. The material gets tacky and stuck together, making it frustrating to set it up. It takes more time, energy, and patience.

The interior walls of the tent or rainfly become sticky because the polyurethane coating that came originally on the tent broke down. This can happen over time, especially if you don’t clean your tent or camp in areas with more dust and rocks. There is a cure to this problem.

Successfully Remove Waterproofing From the Tent

It is time to put the tent in a washing machine using powder detergent. Set it to a gentle cycle and let it wash. After cleaning, spread it to dry for a few hours. If you think there is some residue left on the tent you can make a mixture of vinegar and water, using equal amounts. Rinse off the tent fly with the solution, and air dry it in the shade.

Why Does the Waterproof Coating Wear Off?

The majority of waterproof coating contains polyurethane, as we previously mentioned. In essence, it is a liquid plastic that stays over the tent fabric to enhance its durability and repel water with more success. Once applied, the liquid dries in a waterproof layer that is heat resistant as well. This coating protects the tent from all elements from rain to sun while allowing the nylon or polyester to breathe.

The secret sauce to a good tent is combining maintenance and application. Unfortunately over time, some of the elements on the fabric break down and impact the performance and quality of the tent either way.

PU Delamination

As you use the tent, the polymers that make up the polyurethane start to dissociate from each other. This process is called delamination. It means that the coating has started to break down, causing all kinds of trouble. In addition to being difficult to set up, the disassociated polymers catch dirt and moisture in the fabric. This can lead to odors, making sleeping in a tent an unpleasant and smelling experience.

Improper maintenance can contribute to delamination. This will often happen if you pack the tent after a camping trip before it has had a chance to dry. The damp water molecules will then react with the coating, speeding up the decomposition process. This is often accompanied by mold, mildew, and other health-hazardous microorganisms on the walls of your tent.

Now, even if you notice any issues at this stage, it does not mean that you should throw away your tent. You need to be more thorough to clean it properly and be sure to dry it completely before re-applying a new coat.

Packing up Tightly

Something most people might not even consider is that delamination can get caused by rolling up the tint too tight. Similar to the issue of water molecules being caught in the material, gas molecules from the PU coating are also prevented from escaping if the tent is sealed off tightly.

Off-gassing happens with almost everything surrounding us. However, most of the time we can’t smell them because there are not enough gas molecules surrounding the materials. Trapped gas molecules’ intents can start smelling bad and cause the PU to delaminate.

The easiest fix is prevention, so pay attention when packing away your tent. Pack it loosely and you won’t have to worry about bad odors or damaged surfaces for a while.

How to Apply a New Layer of Waterproofing?

Buying a finishing coat and re-applying it is the easiest way to protect the surface of your tent (in the case you have successfully cleaned and air dried it). Waterproof fabric can be made in one of the following ways:

  1. Put the cloth in a 40% solution of yellow laundry soap, and when it is soaked, remove it and put it in a 20% solution of copper sulfate. Then dry.
  2. Mix a solution of lead acetate (30g per 1 l of water) and a solution of aluminum sulfate (21g per 0.35 l of water), shake and strain through millet. Then put the cloth in this mixture for a quarter of an hour and dry without squeezing.
  3. Put the cloth in a warm soap solution (500 g of soap per 4 liters of water). Then squeeze and immerse in a saturated solution of alum. It is better to prepare a soap solution from 4.5 liters of ordinary soap solution, 25 g of hemp soda, and 450 g of rosin powder.
  4. Moisten the cloth in a specially prepared solution (10 parts water, 4 parts alum, 2 parts fish glue, and 1 part washing soap). Then wring out the cloth and wash it in a 4% lead acetate solution.
  5. Soak a cloth in a specially prepared solution (10 parts glue, 1 part acetic acid, 90 parts water, 1 part potassium dichromic acid), and then dry.
  6. Put the fabric in a mixture of 500 g of milk casein, 12 g of hydrated lime powder, 0.5 l of water, and hot soap solution (25 g per 3 l of water). Soak it thoroughly, dry it, and put it in a 2% solution of aluminum acetate (12 parts alumina per 100 parts water). Remove and, briefly drain into almost boiling water, pat dry

Final Thoughts on Removing Waterproofing From a Tent

Active usage and maintenance of tents are really simple, it takes some time and patience. Air-dry your tent every time you finish camping and remember to store it in a dry, humid-free space. Carefully clean it up in a washer, and/or use the water/vinegar solution. Air dry again, apply a new layer of coating and leave it to set.