What is the difference between a waterproof tarp and a water resistant tarp?
Waterproof tarps can withstand entry of water. Some can even be submerged and will remain impermeable to water.
Polyethylene tarps and vinyl tarps are waterproof tarps. These tarps are easy to clean because spills are not absorbed into the tarp and can be wiped away. Polyethylene tarps and vinyl tarps have the added benefit of being more tear resistant, fire retardant, UV resistant, and typically oil, acid, dirt, grease and mildew resistant.
Waterproof tarps are recommended for construction and industrial environments or for covering boats and cars.
Water resistant tarps can withstand entry of water for only a short period of time.
Canvas tarps are water resistant tarps. People often choose canvas tarps because they are strong and breathable. These tarps are usually treated with oil and wax to make them resistant to both water and mildew, but they can also be made waterproof if they are coated with polyvinyl chloride (PVC) or a similar substance. If angled properly, water will run or slide off the tarp. However, if water pools on the tarp, the tarp will begin to perspire or absorb moisture.
Water resistant tarps are recommended for activities like painting and camping, or for covering equipment or firewood.