Do I Need a Tarp Under My Tent?

Many campers have learned to pack a tarp or ground cloth for camping trips out in the backcountry where sudden rain or other precipitation can soak through the tent floor and turn the whole campsite into a dejected quagmire of mud.

While a properly staked-out tent footprint can waterproof the bottom of your tent and keep your sleeping bag and other gear dry, some campers who hike extensively on their camping trips and want to pack ultralight or just enjoy primitive camping start to wonder at some point whether the tarp or ground cloth is as integral a piece of camping gear as they’d thought the first time they went camping, new tent in tow.

Groundsheets and tent footprints call for much consideration. In a 2-person tent, the tarp or groundsheet maybe ultralight and easy to carry along. But for a 12-person tent or for even larger tents, the tarp you’d use to waterproof the bottom of your tent may not be feasibly portable without some kind of vehicle. So, is the tarp really necessary?

It may seem like a small consideration but a tarp or groundsheet offers extra protection for the bottom of your tent and could make or break an entire camping trip in the right scenario. It’s worth noting that even with a tarp or groundsheet along, it’s never entirely guaranteed that the bottom of your tent will stay dry. Site selection the first time you reach your campsite is really important no matter how waterproof your tent it or how sound the construction of your tarpaulin groundsheet or rain fly.

Beyond what may appear to be its primary duty of helping campers stay dry, tarps and groundsheets can also protect tent floors from abrasions on hard surfaces, so campers with a new tent along may want to ensure the longevity of the tent bottom by placing a tent footprint underneath. As with so many things related to the campsite, the necessity of a tent footprint just depends on the type of camping trip and the goals of the particular campers. Read through this guide for a full consideration of all the pros and cons of a tarp or groundsheet to formulate a well-thought-out plan before your next camping trip.  

How does a tarp help waterproof the tent floor?

A tarpaulin, or tarp for short, is just a large piece of flexible, durable, waterproof or water-resistant material such as canvas or polyester coated with polyurethane or else a plastic material like polyethylene. The tarp most familiar to most campers or outdoor enthusiasts is the large blue plastic kind with grommets around the perimeter to allow for a rope or other fixing mechanism to pass through and keep the tarp fixed and protecting whatever it’s attached to. At home, a tarp is often used to cover firewood or other outdoor material that can’t be brought inside but ought to stay dry in any case. 

Tarpaulin comes in many different designs. Some tarps are perforated, but since waterproofing is likely to be a central concern for campers, perforated tarps are not advisable for either tent footprints or rain flys. Heavy rain will soak right through perforated tarps, although in cases where the campsite is still damp with rainwater from previous precipitation but there aren’t any more storms in the forecast, a perforated tarp could get the job done. Those backpacking with expensive or sensitive camping gear will likely find no need to take the risk of buying anything but the toughest, most waterproof tarp to use as a rainfly or tent footprint. 

Canvas tarps are water-resistant but are not waterproof. If they are arranged so that rainwater will not collect on them and can easily drain away, then canvas tarps will work fine. But sitting rainwater or prolonged exposure to rainwater as might happen in heavy rain will eventually start to drip through a canvas tarp. As a tent footprint on dry ground, a canvas tent will likely suffice as ground cover as long as heavy rain doesn’t come and campers have chosen their campsite wisely and not set up the tent in a place where rainwater will collect on the ground. 

Essentially a tent footprint made out of tarpaulin is convenient for two important purposes at the campsite. Some campers swear against ground cloths of any variety, desiring ultralight backpacking, while others never go on a camping trip without some form of extra protection and waterproofing for their tent bottom. The extra protection and extend the life of your tent, which of course you’ll want to remain 100% intact and without punctures or holes for as long as possible.

It also keeps the bottom of your tent cleaner, which can reduce the amount of time you have to spend on asinine chores once you return home from your camping trip. Perhaps more importantly, the ability of a ground cloth to keep groundwater and rainwater away from your tent is going to prevent all sorts of annoying incidents from happing at the campsite.

Tarps and ground cloths can protect the bottom of your tent

The first time you go on a camping trip with a new tent, you’ll probably obsess with keeping the new tent in the same immaculate condition it’s in when you first pitch it at your campsite. However, many campers often lose this sense of protection for their tents and other camping gear such as sleeping bags as they continue to use them on tent camping excursion after tent camping excursion.

The best method for you to continue proper maintenance and extend the life of your tent is to get in the habit of placing a groundsheet or tent footprint underneath your tent site. As you get more acclimated to tent camping you will do so automatically and not view it as a hassle. 

Many campers who prefer to go without a tarp as a tent footprint find it to be a hassle because they have never been in the worst-case scenario where heavy rain or snow gets through the tent bottom and causes mayhem with camping gear and possibly makes campers sick. Ultralight backpacking does tend to call for leaving everything behind you at home that you can possibly afford not to bring along to the campsite, but the right tarp can be constructed out of moderately thin tarpaulin and weigh just a few ounces. Laying a tent footprint before pitching your tent is no more of a hassle than pitching the tent in the first place. 

Most importantly, even in dry environments, a groundsheet will provide a degree of extra protection between the bottom of your tent and rocks, sticks, and other sharp materials commonly found on the forest floor, the desert sand, or the jagged rocky surface of a mountain. In order to go fearlessly into any environment you desire, a tarp or groundsheet is an essential piece of camping gear that is ultralight and not too much of a hassle. 

For a lightweight material that can serve as a tent footprint or as a handy porch at the entrance to your tent, Tyvek is a solid option. Tyvek is a kind of tarp made out of a high-density polyethylene fiber that is breathable, water-resistant, tear-resistant, and ultralight. Tyvek is very much like paper but much more durable. For situations where your campsite is likely to see snow or heavy rain, Tyvek may be more useful tucked under the front of your tent to provide a staging area that will allow the inside of your tent to stay dry, since you’ll be able to take off your boots on the Tyvek before heading inside from the elements. 

DIY tarps and tent footprints

The most convenient thing about ultralight tarps and tent footprints is that those campers who fancy themselves handy enough can fashion a DIY version of a groundsheet out of tarpaulin, Tyvek, or any other waterproof or water-resistant material available around the house. Follow this step-by-step guide to build your own DIY tent footprint:

1. Find the material you wish to use to construct your tent footprint.

It can often be found at the hardware store or an outdoor retailer. Make sure you buy enough of the chosen material that extends well beyond the size of the bottom of your tent. 

2. Lay out the tarp on the ground and put your tent on top of it.

Make sure the tarp is completely flat and as wrinkle-free as possible to avoid cutting mistakes. 

3. Use a sharpie or similar permanent marker and trace the bottom of your tent.

Try to keep the tent bottom as flush as possible with the ground to get the tightest border trace you can. Make sure not to move the tent on accident! 

4. Cut out the tent footprint you’ve just traced.

Don’t cut directly on the sharpie line, though. Make sure you’re cutting about two inches inside the outline of the bottom of your tent. The logic behind cutting 2 inches within the outline is that the ideal tent footprint is a little bit smaller than the bottom of your tent. If the tent footprint is the same size or larger than the tent bottom it is protecting, then rainwater would collect on the exposed area of the tent footprint. Rainwater pooled in such a way would flood your tent, exactly the opposite of the intended use of a tarp or groundsheet.

Now that you’ve crafted your own ultralight ground cover, you can go camping with a new tent or a time-tested one without worrying about abrasions from the ground or rainwater getting through the bottom of your tent!

Good site selection for camping without a tarp for ground cover

Okay, just to cover both sides of the debate here, let’s consider what campers who venture out on their camping trip without any tarpaulin, Tyvek, or canvas to use for ground cover. Fortunately, without this piece of camping gear, there is only one thing to concentrate on, and that’s selecting your campsite.

The surrounding area at your campsite should be as elevated as possible so that you can erect your tent in a place where rainwater will naturally flow down and away from your tent without soaking through the tent bottom. Before you pitch your tent, pick through the material of the ground and make sure all the big objects like sticks, stones, and debris are clear so that they will not punch through the tent bottom. 

Once all that is done, you’re basically ready to pitch the tent. Make sure you bring some kind of sleeping pad to use underneath your sleeping bag. If your sleeping bag is robust and insulated enough to keep you from heat escaping through the bottom of your tent, then you should be fine sleeping through the night. But in cold locations, the earth beneath your tent bottom will pull heat from you and won’t return any back, so campers in this situation risk having a cold night’s sleep. 

For optimal campsite selection, remember the five W’s: water, waste, weather, widowmakers, and wildlife. We’ve already discussed how important rainwater and drainage are, but drinking water is equally important. Campers planning on treating river or creek water with a water filter or similar piece of camping gear have to toe the line between setting up a campsite near enough the water source to be convenient but far enough away that a sudden heavy rain won’t flood the source and drench their tent bottom. Waste is obvious enough: campers will need a convenient way to dispose of waste when they leave the campsite.

Weather is relevant to points already discussed vis-a-vis tarps and tent footprints. Natural cover like trees and overhangs and add extra protection against water permeating the tent bottom. But attention is critical because the next W is widowmaker, a name given to potentially fatal accidents caused by something like a heavy tree branch suddenly falling on your tent. If you use trees for extra protection against the weather, make sure none of them are dead or close to falling on top of you. 

Wildlife is an equally important consideration. There are plenty of precautions to take against larger animals like bears or foxes, but make sure you aren’t setting your tent up on top of an ant colony or a wasp’s nest. A tent footprint can offer some slight protection against insects coming in through the tent, but if you tend to leave the front entrance to your tent open, it’s likely ants will get in if you’re trying to sleep right on top of them. Overall, there are many useful advantages to tarps and tent footprints and not many drawbacks. 

Final Verdict:

For all but the most hard-headed or ultralight backpacking-obsessed campers, a tarp or groundsheet is a super-handy piece of camping gear that doesn’t add too much weight to the pack and only takes a few extra minutes to set up at the campsite. To protect the bottom of your tent and extend the life of your tent, a tent footprint is a utilitarian dream with no special features or complicated operation. It is simply a bit of extra protection between you and the ground. It’s ideal for campers who want to retain heat inside their tent, add a small degree of comfort to the tent bottom, and make sure nothing pokes a hole in the tent’s floor. 

All campers know how rain can put a damper on an otherwise fulfilling camping trip. A groundsheet, tarp, or tent footprint can cover the ground beneath the tent’s floor and prevent rainwater that has already fallen at the campsite or rainwater from heavy rain that’s currently falling from permeating the tent bottom and soaking every camper inside. To avoid illness and ruining camping gear with sensitive electronics inside, and to preserve your own ability to wake up with the energy to go out hiking and interacting with the great outdoors like you should on any worthwhile camping trip. 

Only the most foolhardy campers would go without a simple tent footprint to avoid all this trouble. With so many ways to craft a durable DIY tarp out of Tyvek, canvas, or any other material, there aren’t too many reasons not to add a few ounces to your pack to bring along a piece of camping gear that could make the difference between a cold, soggy camping trip and a successful camping trip into the backcountry where, despite heavy rain or snow, all campers involved managed to make the best of it and see the great outdoors in the rain, an opportunity not taken by the vast majority of campers. Now that you know the in’s and out’s of tarps and tent bottoms, you’ll be much better prepared to protect the bottom of your tent and extend the life of your tent next time you go camping. 

Bonus tip: Watch this step-by-step instructional video to learn how to make your own DIY Tyvek tent footprint and tarp for next to nothing!