How to re-waterproof a tent
Most modern tents are so robust and durable that they should remain waterproof for many years after purchase. However, if you have had a tent for a very long time, then there is a chance that it will start to lose its efficacy when it comes to waterproofing. If this is the case, then there might not necessarily be any need for you to purchase a new tent, if you want to hold on to the one that you have and there are no other pressing issues with it. From an ecological standpoint, it is also very understandable not wanting to buy a new product when you can simply inject extra life into your current one with a ' make do and mend' attitude. Thankfully, there is an effective way to re-waterproof your tent and this way you will not have to throw away a tent that is otherwise in fine working order.
How to know when to re-waterproof your tent
This might sound like a silly question, as you will know when to waterproof your tent if water is dripping in when it rains. However, there may not be such clear evidence that your waterproof material has failed. Plus, you might even want to test out how waterproof your tent still is before each use when you have a particularly old tent, just so that you don't find out it is not working when you are already out on your trip.
When your waterproof tent material is still operating to 100%, you should see that the water simply flows or bounces off the outer surface in beads. You can even test this by pouring some water directly onto the outer surface. You should see that the water beads out, bouncing off the surface, and with a few shakes of the tent material, the area where you poured the water should be clear.
However, if your waterproof tent no longer offers full protection, you will see instead that the area you pour the water onto will soon become damp and soggy. This is known as "wetting out" (absorbing water). Instead of bouncing off the surface, the surface will become wet, as the repellant characteristics of the material will no longer be working. The water might not immediately come through the material to the inside of the tent, but it will do just that given enough of a sustained period of rain. So, if your tent's outer surface is absorbing any water rather than repelling it into beads that can be shaken off, you know that you will be under risk of sleeping in damp conditions next time you use it should it rain.
Watch out for mistaking condensation for leaks. Modern tents will be very unlikely to leak unless they are damaged. Some people occasionally see a light amount of dampness on the inner surface of a reasonably new tent and think that this is a sign of a leak. It will in fact most likely be trace amounts of moisture inside the tent evaporating and then, through condensation, being changed back into water as they hit the surface. However, with many of the high-quality modern tents that you can buy these days, this should never be a serious problem, as the designs are structured so as to remove condensation with air flow. So, even if you see a slight amount first thing in the morning, it should soon dissipate. The place that it is in fact more likely to spot a leak is not on the inside panels of fabric, but on the seams of an old tent.
Resealing your seams
If you have had a tent for years, then the seams will be one area to keep an eye on for signs of weathering. If the seams are starting to become a weak point, then you will want to use a seam sealer, which we stock here at our store. Having a sealant to hand when you are out on a trip is a sensible practice, as it means that you won't have to worry about sleeping in the wet even if you are unlucky enough to have your seams become faulty when you are out on an adventure.
Re-waterproofing your tent fabric
When it comes to the fabric itself, you will also find a range of very effective and reliable products on the market that come in the form of sprays. Take a look at our range of protector and re-proofing sprays from the likes of Fabsil and Nikwax for inspiration. We recommend checking out Fabsil Universal Protector with included UV protection for this job. To make sure you have enough for your tent, we recommend buying a bulk bottle and decanting it into a handheld spray gun (the kind you would use for watering house plants). Once you have a waterproofing agent ready, you will need to pitch your tent. It is best to do this on a dry and warm day if that is possible, so keep an eye on the weather forecast!
Make sure the tent is clean when you take on this task. You will simply want to rinse and wipe your tent clean and then, if you are using a dry-application re-proofing spray, such as Fabsil, you will need to wait till it is dry. There are some sprays on the market that must be applied when the surface is wet, such as Nikwax. Just make sure that you carefully read the instructions of the spray to work out which type it is before use.
Spray your way around the tent so that it has an even spread across the tent fabric. Make sure that every area is covered as you go. If you are using a wet re-proofer spray, then you can use a cloth to wipe it all over the surfaces to make sure that it is evenly spread, then leave it to dry as per instructions on the bottle. The dry sprays are to be used in the style of spray paint cans - time to get your Banksy on! It will leave a darkened patch as it covers the surface, so you should know when to move onto the next section. To be certain of success, you can also wait for the first coat to dry and then apply one more coat.