A 20x40 tarp is a great way to go to keep your belongings sheltered. These 20 x 40 tarp is available in a wide range of sizes, depending on your needs. You'll find a 20 by 40 tarp is waterproof, rip resistant, serves as UV protection during the heat of the summer day, and assists in melting snow during winter storms. You simply can't go wrong with a 20'x40' tarp for your standard outdoor protection needs.