Camping tents of all shapes and sizes come in two basic configurations: single-walled tents and double-walled tents. But given that most campers and backpackers prioritize minimizing pack weight, why do some tents have two layers? And why are these the most popular?
Double-Walled Tents: What Are They?
As the name suggests, a double-walled tent is made with two layers of fabric or “walls”—the tent body and a rainfly. The tent body provides the tent’s structure and forms the sleeping area, whereas the rainfly, which is pitched over the tent body, provides protection from the elements.
Double-layered constructions are used to achieve waterproofness and breathability. The materials used in the body of tents are breathable but not waterproof, whereas the rainfly is waterproof but not breathable. Used together, the two layers complement each other: moisture vapor escapes the tent body through its breathable fabrics and mesh panels to reduce condensation and the rainfly keeps out precipitation. Additionally, the gap between the two “walls” provides the airflow required to limit the buildup of condensation on both the fly and the tent body.
Single-walled tents, by comparison, are typically made with tougher fabrics that are both waterproof and breathable but usually to a lesser degree than in double-walled tents.
The Benefits of Using a Double-Walled Tent
The most notable advantage of using a double-walled tent over a single-walled model is moisture management. As mentioned above, not only will a double-walled tent stop precipitation from entering your sleeping space but will also limit the amount of condensation that builds up on the tent’s interior thanks to the ventilation provided by the breathable tent body fabric and the airflow between the body and the rainfly.
Additionally, double-walled tents allow for more gear storage as most models have a vestibule area between the tent body door and the rainfly, a feature that can boost living space inside the tent by allowing you to stash gear safely outside the sleeping area.
In short, double-walled tents are the most suitable choice for wet or humid conditions and/or when looking to maximize living and storage space.
Finally, double-walled tents are also usually stronger, more durable, and warmer than single-walled tents, and if you happen to damage the rainfly or its waterproof coating wears out, you can replace it at a lower cost than buying a new tent.
The Drawbacks of Using a Double-Walled Tent
The only significant drawbacks to using double-walled tents are that some models are trickier and more time-consuming to pitch and stake out than single-walled varieties, and they can also weigh considerably more without offering (in some cases) any upgrade in terms of waterproofing or season rating.
Tips for Using a Double-Walled Tent
To optimize the performance of your double-walled tent, you should take particular care during setup.
First of all, make sure the floor is pegged out tightly so that the tent poles are in the correct position and will, therefore, prevent the rainfly from coming into contact with the tent body. If this happens, airflow between the two layers will be restricted, thereby increasing the likelihood of condensation inside the tent and the potential for saturation of the contact area in heavy rainfall.
Secondly, while it’s tempting to skip a few guy lines when pitching your tent in good weather, it’s well worth using the full complement and ensuring the rainfly is taut as, again, this will prevent the fly from coming into contact with the tent body and also provide extra stability should the wind get up during the night.
Finally, if using only the tent inner on particularly toasty nights, always leave the rainfly at least partially attached or pegged out in case conditions take a turn for the worse and you have to put it on in a hurry.
So, Why Do Tents Have 2 Layers?
In short, it’s all about minimizing water ingress whilst maximizing ventilation. While a single-layer tent can provide solid waterproofing, a two-layer model is far likelier to keep you dry and has the added benefit of permitting ample to airflow to stave off stuffiness and condensation.