Ground tarps are one of the first things you neet to set up when you get to the campsite. Search the area for a suitable location to set up your tent, and clear all debris from the location that you want to place your tent. Place your ground tarp in the location you want your tent to be placed. Pitching your tent on the tarp allows you to stay clean while putting up your tent. Once you have fully assembled your tent fold the ground tarp under the four corners of your tent. You don’t want any of your tarp sticking out. If it sticks out it acts like a funnel for the rain to pour into your tent.
Here is an example of a tent set up for a Scout family camp. The tarp underneath is improperly set up. This setup will allow the water that sheds from your rainfly to hit the tarp and go under your tent. The water is supposed to shed to the ground to be absorbed as your tent stays nice and dry. This setup won’t allow for the tent to be staked properly. If they were to stake the tent they would have to poke holes in the tarp which will ruin it.
The best ground tarp is called a footprint. footprints are ground tarps that are the same size as the tent floor. Having a custom footprint allows you to save on pack space. This ensures only the underside of your tent is covered. Most footprints are designed to fit in the bag with a tent and this is a huge space saver. This allows you to use the other tarp as a shelter for a cool place to sit out of the elements.