Guest Post by: Casey Fiedler of Outside Pursuits
If you’re anything like me, chances are good that you started off as a hiker with a pretty cheap tent. Mine was from Sam’s Club – Swiss Gear to be exact. That tent was about as waterproof as a slice of Swiss cheese and no amount of waterproof tent spray could save it. I had made a mistake.
I bought a lot of my early camping and hiking gear without fully understanding what makes them waterproof. More importantly, I had no basis for understanding what made one item good at being waterproof and another terrible at it. You’re probably wondering something similar.
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What is a waterproof hiking tent made from? What sets one apart from another? How can you be sure you’re not getting fleeced when you buy one?
With hundreds of night spent on the trail guiding backpacking trips around the US, I’ve come to an intimate understanding of waterproof gear. Today I’d like to share that with you to help you in your travels!
Materials Used for Tents
Today you really get about 3 solid options when it comes to tent materials. Of those, two are very similar in many regards, and the third is an alien outlier.
- Mylar Laminate (cuben)
Nylon, the same material responsible for many ugly fashion inventions of the 90’s, is arguably the most popular tent fabric. It’s a fully man-made fabric that is quite affordable, durable, and relatively lightweight. If I had to guess I’d say 60% of modern tents are made from nylon.
Polyester is slightly more expensive and a little less common than nylon. In most regards, they’re fundamentally similar with respect to tent creation. Polyester, however, has the potential to be slightly lighter in some implementations but this depends heavily on manufacturer construction methods and the user’s intended purpose for their gear.
Largely I consider polyester and nylon tents to be basically equal for all but the biggest gram weenies (ultralight hikers) or ultra-hikers.
Last, but certainly not least, is cuben fiber now known as mylar composite. Cuben fiber started out as a lightweight sandwich of mylar plastic with spectra fibers smashed in between. This stuff is crazy strong and insanely lightweight!
A Note About Denier: Denier refers to how thick a polyester or nylon fabric is. 10 denier is about as lightweight as it comes while 200-300 denier is the equivalent of a car seatbelt or more. Things like the bottom of your tent (where it contacts the ground) should be made from more robust fabrics (higher denier) while other components like the rainfly can be made from oober-light fabrics in the 10-15 denier range.
Mylar laminate is also crazy expensive and only small cottage industry manufacturers work with it. Why? Because most hikers don’t like the high cost, its weakness to puncture, or the odd crinkly sounds and feel of the plastic bag-like material.
Mylar laminate is popular among the die-hard ultralight hikers and users who do the best with cuben fiber tents fully understand the materials and its limitations/drawbacks. Not recommended for beginners.
Tent Waterproofing Options
When it comes time to waterproof the fabric your tent is made from most manufacturers follow a similar process. Both nylon and polyester are inherently very water resistant in most weaves used for tents. Mylar composite, however, is inherently fully waterproof by itself (which is considered one of its major advantages as a material).
To make nylon and polyester waterproof generally silicone is applied in the factory. Before the fabric leaves the textile mill the nylon or polyester will be impregnated with a very thin layer of silicone which is waterproof, flexible, and durable.
After this process has happened the fabric will now be known as “silnylon” or “silpoly” indicating the addition of silicone.
While there are other waterproof fabrics out there, they’re very rare and generally not applicable. For instance, Gore-Tex and eVent are both examples of waterproof breathable membranes and do not get used in tent applications. Another example is PU (polyurethane) coated nylon – a fabric popular on inexpensive waterproof jackets but very rare on tents.
Sealing Up Tent Seams
Great, so now we’ve found some good waterproof fabrics. It’s time to sew up the tent!
The only problem is… when you sew a tent it puts thousands of tiny needle holes into that waterproof silnylon or silpoly. These little holes do leak and they will cause you headaches if they’re not fixed!
In order to stop leaking from around the seams used to sew together a waterproof tent a process generally known as “seam sealing” must be implemented. Seam sealing uses one of several various waterproofing methods to block up those needle holes and keep you dry.
Seam tape is a sticky waterproof tape applied over the sewn seams of a tent. Usually, this tape is applied at the factory and adheres to the tent through a process of heat and pressure which fixes it firmly in place.
Seam tape is visible on the inside of tents, jackets, pants, and other waterproof hiking gear. Just turn your tent or jacket inside out and look for a thin line of transparent tape along the seams to see if it’s there!
Silicone seam sealer is a liquified silicone gel that you can purchase in various forms. It’s used for sealing seams, repairing tears, and other DIY processes. My personal go-to is the Gear Aid Seam Grip.
If you ever buy a cottage industry tent you may be faced with siliconizing your own seams. It’s a good process to master because it comes in handy for repairs on seam tape tents, too! The process is super simple – just follow this easy video to touch up your tent or seal a new tent/tarp.
Tent Floors and Footprints
Now that we’ve covered fabrics and waterproofing, there is just a little bit left to know about your tent.
Bathtub floors are a type of tent floor where the thick, waterproof floor of your tent wraps up the side walls of the tent. Usually, these side wraps stretch up 2-6” along the sides of your tent and help protect against rain splatter and any running groundwater during hard storms. Most tents utilize a design similar to this even if they don’t advertise it as such.
Footprints are basically tarps that go on the ground under your tent. Usually, they’re shaped to match the silhouette of your tent and should be made from durable heavier denier fabric.
Footprints are most often for protecting the bottom of your tent from scratches, scrapes, and punctures that can occur as a result of sharp objects on the ground.
I don’t usually use or recommend footprints for tents because careful site selection helps mitigate any risk of tent damage, to begin with, and they add a lot of weight to the pack.
Additionally, many users fail to properly “hide” the footprint under the tent. Any exposed surface area of footprint outside the tent floor will act as an inadvertent rain catch essentially channeling running water down under your tent. Not good!
There are tons of different fabric choices out there for your next tent. More than likely you’ll be choosing between silnylon and silpoly, however, simply due to their wide availability and affordable prices. In this article, I’ve attempted to cover the basics while helping you dip your toes into the moderate and advanced concepts when it comes to waterproof tents.
As you dive into the world of hiking, camping, and backpacking you’ll eventually learn some things the hard way. There’s no way around it – I think everyone I know has owned at least 3-4 tents. Understanding the details of your waterproof tent, however, means you’ll be able to make more educated decisions and waste less money trying new tents over time.
Let us know what tent you have in the comments below and how waterproof (or not!) it is.
|Casey has a degree in Outdoor Education and has spent years guiding backpacking trips on the trail around the US. He works with Outside Pursuits to write gear-based outdoor articles on tons of topics!|