Are Tents Waterproof? A Hands-On Test!
Camping can be a lot of fun, in all weather conditions. But isn’t as fun if it’s raining and you’re stuck in a wet tent. So, are tents waterproof?
Most tents are designed to be waterproof. The waterproofing of tents is quantified by their Hydrostatic Head (HH) rating, which typically ranges from 1,000 mm to 10,000 mm. Leaks, holes, and folds must be sealed and maintained to keep a tent waterproof over time.
Read on to learn more about tents and how waterproof they are, how water gets inside a tent, and how to keep a tent dry.
Are tents waterproof?
While tents are designed to be waterproof, water can still get inside if the rain is pouring too hard, if the tent is not set properly, or if the material of the tent degrades. Waterproofing can never be perfect.
The way tent waterproofing work is with redirection of water, similar to what an umbrella does. The fabric the tent is made of is waterproof, up to some level. When the rain pours on a tent, it splashes over the tent fabric and away. If there’s any way for the water to get inside the tent, it will.
Over time, tent material can degrade, and water can get in. For example, I had a look at the floor of my family’s old tent, pointing it towards the sun, and saw a lot of small holes water can get in. This happens over time. Old tents need to be maintained to keep being waterproof.
The floor material of tents is usually made of heavier material that’s also more waterproof than the sides and top of the tent. That’s because unlike the top of the tent, water can pool around the floor, and if the material isn’t waterproof enough, they’ll eventually get in.
Tents are designed for a different number of seasons and are usually rated with different Hydrostatic Head (HH) ratings, which indicate how waterproof a tent is.
What is Hydrostatic Head (HH) in a tent?
The hydrostatic head (HH) rating is a simple measure of how waterproof materials are. It measures the amount of water pressure that can be applied on a piece of fabric before water droplets start appearing on the other side((MSR, Tent Fabrics Part 2: Waterproof Ratings)).
While a higher HH rating on the tent fabric does indicate it can withstand more water pressure, the design of the tent has a lot to do with its waterproofing level.
Here’s a table that estimates the worst weather conditions tents with different HH ratings can handle:
| Hydrostatic Head Rating | Weather |
|---|---|
| 1,000 mm | Very light showers |
| 1,500 mm | Light showers |
| 2,000 mm | Heavy rainfall |
| 3,000 mm | Heavy downpours and wind |
Generally, tent HH ratings vary from 1,000 mm to 10,000 mm, but except for very special tents that are designed for extreme camping conditions, most tents are rated between 1,000 mm and 3,000 mm.
Testing tent waterproofing
I took an old tent my family had for years, and sprayed it with a hose, to try and see whether water gets in. It’s a basic cheap tent and is a few years old.
I tried spraying the water mainly from the top, as rainfall does. I used a relatively low water pressure. This mainly tries to mimic light rainfall.
After doing that for a few minutes, I opened the tent and looked for any leakage, or traces of water inside it.
Surprisingly, the tent did quite well. I saw a very minimal amount of water, and it seemed like it mainly got in from the bottom of the tent, from small holes in its floor. The top fabric of the tent kept most of the water out.
I think proper camping tents should probably do even better, and handle light rain quite well.
Ways water can get into a tent
As I mentioned before, even though tents are made of waterproof fabrics, water can still sometimes get it. Let’s review the different ways water might come into a tent, so we can fix the issues.
1. Water comes through leaks and holes
A brand-new tent should be relatively waterproof. But no material stays new forever. Over time, especially when used frequently and not maintained and stored correctly, tent material starts to degrade.
New tents are usually coated with waterproof coating, but over time they wear off.
This means that over time, the tent becomes less waterproof, and small holes and leaks that water comes through can appear in the material.
2. Water comes through seams
If you’ll have a look at a new tent, you’ll notice the seams are taped from the inside of your tent.
Seams are weak spots, where if not sealed correctly, water can easily come through.
The tapes that cover seams degrade over time, and sometimes even peel off, leaving the seams unsealed. This creates spots where water can come into the tent.
3. Water pools around the tent or its folds
The fabrics tents are made of aren’t perfect. If you soak them in water, they will get wet. That’s why if a significant amount of water pools around the material of your tent, it will eventually come into the tent.
If you don’t stretch your tent properly, it’ll have folds water can pool around, and you’ll eventually find yourself with water inside the tent.
Water can also pool around your tent, because of the environment you’ve set up in. For example, if you’ve set up in a dip, water can flood your tent. You generally want to set up in a sport that’s higher than its surroundings.
4. Water comes through low HH-rated tent fabric
As mentioned above, not all tent fabrics are created equal. many are treated with waterproof coating, making their HH rating much higher.
If your tent is rated with low HH, it’s not designed to withstand heavy rain. It water pressure from the rain builds up too much, water can get inside the tent through the material.
As mentioned before, the waterproof coating can degrade over time, effectively lowering your tent’s HH rating.
5. Water condenses inside the tent
We don’t think about it too much, but when we breathe, we also breathe out water vapors from our lungs. If the tent isn’t properly ventilated, the water can condense inside the tent.
This happens to a lot of people, who wake up in the morning and see droplets at the top of the tent. That usually happens because of poor ventilation.
How to waterproof a tent
Waterproofing a tent can be a bit of a hassle, especially if you’re not sure where water comes in. In general, if water starts going in on light showers, you should probably refresh the waterproofing on the entire tent, instead of limiting the process to a specific area.
The process of waterproofing a tent:
1. Repair holes and leaks in the tent
The first step in waterproofing your tent is to repair any holes or leaks in the material. These are where a majority of water comes in.
To repair any big holes, you can use a fabric repair patch or a mesh patch. You simply need to clean the area with rubbing alcohol, and shape the patch to be a bit bigger than the hole, any apply it to seal the hole. If the area where the hole is in is a high tension area, you can patch both sizes for extra strength.
You can get a tent repair tape in any major outdoors retailer. For example, this repair tape should do just fine.
The process is also shown in this helpful video:
If your tent is old an the material is flaky, you might need to address small holes that appear as a result of material degradation. You do that by repairing the coating of the tent.
Before doing that, you should clean you tent with water. You want the sealant to be applied directly on the material without too much dirt.
To repair the coating of the tent, all you need to do is clean the flaky area with rubbing alcohol, and then apply a layer of tent sealant on the material. Leave it out to dry as the label of the sealant requires, before storing the tent.
You should apply a thin layer of the sealant, so a small bottle should be enough. This tent sealant should do the job.
2. Seal the seams of the tent with sealant
The next step is repairing the sealing on the seams of your tent. To do that, first clean the material on and around the seams with rubbing alcohol. When clean, apply a dedicated sealant along the inside of the seams and let dry.
Notice that different sealant is required based on the fabric you tent is made of, so when getting a sealant check what materials it should be used on.
The entire process is also shown in the youtube video:
3. Waterproof the tent’s fabric with new DWR coating
This process simply improves the HH rating of the fabric of your tent back to its original state, if the coating degraded.
To reapply the Durable Water Repellent (DWR) coating, you first need to soak the tent in water and clean it. When still wet, set your tent up. Apply a DWR coating spray over the tent fabric, and let it dry for a few minutes. After that, you can remove excess material with a cloth, and let the tent dry completely.
After refreshing the DWR coating, the tent fabric should be much more waterproof.
How to keep your tent dry when camping
There are a few simple steps you can follow to make sure your tent stays dry when camping:
1. Choose a high spot when setting up
When setting your tent up, you want to avoid areas where water could pool around your tent.
For example, if you’ll set up in a spot lower than its surrounding, gravity will pull waters and create a pool around your tent, which will eventually come inside the tent.
Setting up on an area with a slope is a bit better, but you’re still running the risk of water pooling on the higher wall of your tent.
Instead, look of a sport that’s higher than its surrounding. Setting up there, water will tend to flow away from your tent, minimizing pooling.
2. Stretch the tent and avoid folds when setting up
Properly stretching the fabric of your tent is essential to avoiding folds where water can pool. A well stretched tent also repells water better, similar to what an umbrella does.
3. Ventilate the tent as much as possible when camping
A well ventilated tent is more pleasant to sleep in, but it’s also less like to have water condensing in. Water vapor from your breathe will flow outside as fresh air from the outside flows in.
Most tents have ventilation holes which you should keep clear for ventilation. If you need more fresh air you can open a window, though that’s usually no recommended when trying to keep the inside of your tent dry.
Conclusions
In this post, we’ve covered multiple topics on how waterproof tents are, and tips on how to keep dry.
Camping in the rain isn’t ideal, but keeping safe from the elements is one of the reasons you own a tent in the first place.
Following the tips in this article, you’ll have a better chance of surviving the rain while staying dry. Keep having fun!
