PE (polyethylene) tarps are usually waterproof. This type of tarp is often used for rain shelter or temporary waterproofing needs because they provide good waterproofing properties in the short term. The waterproof properties of PE tarps usually come from the characteristics of its material and the coating or treatment during the production process.

However, it should be noted that the waterproof performance of PE tarps may vary depending on the quality and manufacturing process. Some high-quality PE tarpaulins may use additional waterproofing treatments or add a waterproof coating to improve their waterproof performance. Therefore, when purchasing a PE tarpaulin, it is best to check the product description to ensure that it has sufficient waterproof properties to meet your specific needs.

Overall, most PE tarps can provide basic waterproofing, but to get a higher level of waterproofing, you may want to consider some special treatments or high-quality products.