Can you use a Sleeping Bag as an Underquilt?

So you have an extra sleeping bag and you want to utilize it instead of getting rid of it. Maybe it can substitute something and save you money. Sleeping bags are good insulators so an extra one can help you stay warm during the night. Sleeping bags can be used as a substitute for sleeping pads and especially an underquilt during hammock camping. But you may be confused. Can you use it as an underquilt? Yes, you certainly can.

Let’s see how you can do that.

What is an Underquilt?

An underquilt is simply a sleeping bag without a hood, a back, and a zipper. Sleeping bags and quilts are made using the same materials. An underquilt is simply an insulated quilt designed to hang beneath your hammock to prevent heat loss.

A sleeping pad solves the same heat loss problem when you are camping in a tent on the ground. A sleeping pad creates an insulated air space beneath you and it also performs the same function in a hammock as it does during ground camping.

You can use an underquilt in place of a sleeping pad during ground camping as both have the same function. But using an underquilt on the ground is not recommended. Underquilts are often made of down fill. The campground can often become wet. We all know that down loses its insulation if it becomes wet. Underquilts are also less effective on the ground as we will see.

If you are reading this guide, then it will be assumed that you are probably looking for guidance regarding hammock camping.

Why do you need it?

As mentioned above, underquilts are more suitable for hammock camping. They don’t cause any discomfort by coming between you and the hammock. Instead, they keep you warm by hanging beneath your hammock.

But if you have a sleeping bag in a hammock, would you still need an underquilt? Yes, you would. Sleeping bags and underquilts, both use down fill to provide warmth. Down has small spaces in between that trap air forming small air pockets. The same mechanism occurs in sleeping pads that have air pockets in the foam. Air is a bad conductor of heat which is how sleeping pads, sleeping bags, and underquilts stop heat loss from your body.

When you lie down on your sleeping bag the down is crushed under your weight. The crushed down loses its air pockets because now there are no spaces in between the down. As a result, your sleeping bag loses its insulation and can’t keep you warm anymore.

Sleeping pads have foam in it that doesn’t crush when you lie down on it. However, it does lose some of its insulation. It is because of the same reasons that an underquilt becomes ineffective on the ground. An underquilt remains warm when it’s hung beneath a hammock where your weight doesn’t crush it.

Using a Sleeping Bag as an Underquilt

Since sleeping bags are made of the same materials, they are essentially the same things. So, yes, they both can be used during hammock camping. You can hang it under your hammock just like an underquilt and it will work the same.

Some Cons

However, there are some things that you should keep in mind before using a sleeping bag as an underquilt. First, your sleeping bag should have a full-length zipper that allows it to open up like a quilt. Rectangular sleeping bags are more suitable for this type of use. Otherwise, your sleeping bag won’t be as effective as it won’t open up.

Secondly, sleeping bags are heavier to carry. The addition of a hood, a back, and a full-length zipper also adds additional weight. Modern sleeping bags are lighter because of advances in the technology of the materials used. But if you have a sleeping bag from the 80s or 90s, they are heavier than the ones available now.

How to Hang a Sleeping Bag Underneath a Hammock?

There are several ways of attaching your sleeping bag under your hammock. Most of them require you to weave a web of cords under your hammock, then pray it doesn’t fall in the middle of the night plus it’s tedious work.

You should try one of the easier ways that don’t require too much time and effort. One of the easiest ways is to buy a cheap cargo net hammock that is close to the size of your main hammock. The cargo hammock is just like tying an underquilt under your main hammock. The only extra step is to put the sleeping bag inside the cargo hammock.

This is all based on the assumption that the extra sleeping bag you have can open up flat into a quilt using full-length zippers. If it doesn’t, then you can use it as your tip insulation and find something else for bottom insulation.

Make sure that you do all this testing work in your backyard or in a car camping situation where you have easy bailout options if the need arises. Once you know it’s going to work for you, you can begin to modify it to your requirements.