You may be thinking, “Why do I need a tent footprint or groundsheet? Isn’t my tent designed to be insulated already?” Although the base of your tent is designed to protect against the cold, a tent footprint and groundsheet provides additional waterproofing and insulation against the outside temperature. It guarantees that you will always set your tent up on a dry surface and helps protect your tent against the ground.
Tarps are another popular choice used by campers as an alternative to a dedicated tent footprint. However, tarps have a number of issues when it comes to substituting them.
Tarps aren’t made to fit the exact dimensions of your tent. This means that you’ll need to fold it to fit under your tent, as if there are parts hanging out, water can pool under your tent. Tarps are also far bulkier than a tent footprint, making them less ideal for space-conscious campers.