For reliable temporary protection at an affordable price, rely on discount tarps from A1 Tarps.
Discount tarps is a misnomer, here: While these are cheap tarps, they don't suffer from a lack of quality. The wholesale tarps you find here are made from a polyethylene material that is naturally resistant to rot, mildew and mold. These are a good solution for when you need something fast and affordable. They are also outstanding at dealing with emergencies or surprises, from home damage to protecting groceries from rain in the back of a pickup.