Do You Need A Groundsheet For A Bivy? | A Quick Guide

For ultralight hikers/backpackers, bivy camping is one of the most preferred methods of camping because of its lightweight design as well as overall element protection.

The fact that they are relatively easy to set up and easy to clean makes them a worthy competitor to traditional tents and hammocks.

So what about groundsheets then? Do you need them as you do for tents, or are they unnecessary for this setup?

When bivvying, you’re probably already using a bivy sack with a waterproof SilNylon ground layer that prevents water from entering from the ground. So you don’t need an additional groundsheet to protect yourself from dew and flowing groundwater. However, if you’re using an expensive breathable and waterproof bivy, you’ll want to extend its life as much as possible, and a groundsheet will do just that.

To help you better understand this, I did some research and put together a more detailed guide below.

What Are The Advantages Of Using A Groundsheet With A Bivy?

Here are some of the advantages of using a ground sheet:

Extra Water Resistance

Although I previously stated that a bivouac sack, also known as a bivy sack, has a waterproof bottom, this is only true for those made with SilNylon (Silicone + Nylon) coating.

However, for bivvies made of different materials, or if there is a puncture anywhere, it is best to use them in conjunction with a groundsheet to prevent water seepage inside your sleeping system.

Further reading: How To Repair A Bivy Sack?

After all, you don’t want to wake up in the middle of the night wondering if bivy camping was a good idea in the first place, do you?

Increasing The Lifespan Of Your Bivy

A bivy sack made with highly breathable and waterproof materials demands more care and love than one that is inexpensive and has just decent water resistance.

After all, the price difference between a drawstring water-resistant bivy made of low-cost materials and a zipper waterproof, breathable bivy made of high-quality materials can be as much as $250 or more.

If interested, you can check this article on How To Clean A Bivy Sack?

With the footprint underneath, friction between the ground and bivy is reduced, which keeps wear and tear to a minimum.

Avoiding Sleeping Pad Punctures

This actually depends on how you position your sleeping pad (inflatable pad); do you place it outside the bivy and underneath it or do you place it inside along with your sleeping bag.

If you do the former, especially if you are backpacking or hiking in the backcountry, you are playing Russian roulette with the durability of your sleeping pad.

If your luck stays good, congrats, you get to see another day of your sleeping pad intact. However, for a not-so-lucky day, you may have to work with a punctured pad, that offers no insulation to your sleep system whatsoever.

Thus to remove this element of chance its best to use a groundsheet below the pad and then use it.

Versatility

You can purchase a groundsheet for bivy camping, but it does not have to be limited to bivy camping only.

You can use the same gear for any kind of setup (tent, hammock) and stay protected from bad weather like heavy rain or precipitation in general.

Curious read: Can You Use A Space Blanket As A Groundsheet?

What Are The Different Types Of Groundsheets?

Here are some of the most common groundsheet variations:

1. Tarp

This is probably the most commonly used footprint across a wide range of setups. Among all the options, tarps probably cost the least, are decently water-resistant, and can be used other than as groundsheets as well.

That said, as I mentioned it’s water-resistant not waterproof, it’s great for prolonging the life of your bivy but if you were looking for water protection this may not be your best option.

2. Mesh

A mesh footprint similar to a tarp is quite inexpensive (however a bit costlier) and is also quite popular among campers.

However, unlike a tarp, a mesh groundsheet is made to be more breathable thus being less water-resistant, making them less suitable for wet conditions.

That said, they are quite easy to clean and offer great protection against friction from the ground.

3. Canvas

A canvas groundsheet is unquestionably the most durable rain gear available, as it is both waterproof and breathable.

However, it is not without cost; a canvas groundsheet is significantly more expensive than the others and also takes noticeably longer to clean and remove any stains.

4. Polycro

A polycro mat is very similar to the cooking foils that you use to preserve your food for longer, except it’s much bigger and more durable. It is 100% waterproof and prevents any moisture from getting in or out.

Oh, and did I mention they are super inexpensive?

5. Space Blanket

A space blanket, like polycro mats, is completely waterproof and extremely affordable. However, unlike a polycro mat, a space blanket also provides some degree of warmth to your sleeping system.

In fact, they are so dependable that you can use them as a separate shelter.

Still Curious? Why not check this article on Emergency Blanket Vs Bivy

6. Tyvek

A Tyvek fiber is very similar to paper, except that it is entirely made of synthetic materials and is completely waterproof.

It is also one of the most commonly used groundsheets, but they make quite a bit of sound when in use, which can put some campers off.

How Do You Attach The Groundsheet To The Bivy?

Setting up a groundsheet for a bivy is probably the easiest setup for a groundsheet out of all the others.

Just like a bivy is extremely simple to set up, which you can do by spreading on the ground and then getting inside, so too is a groundsheet.

Spread out the footprint, place some stones so that it doesn’t get blown away, and then set up the bivy on top of it. That’s all!

Final Thoughts

If your bivy has a ground layer made of SilNylon or equivalent waterproofing, then you can easily forsake the groundsheet and save a few ounces of pack weight.

However, if you want to extend the life of your bivy while also keeping it clean, investing in a good quality groundsheet may be a viable option.

Anyways, as always, stay safe and happy adventuring!