10 Major Things to Keep in Mind while buying Waterproof Tarps
Here are the 10 major things to keep in mind while buying waterproof tarps or tarpaulins:
1. Size
Regardless of what waterproof tarp you buy, it's best to buy one that is slightly bigger than the area you want to cover. This will ensure maximum waterproofing, and also allow some wiggle room when placing the waterproof tarp on an uneven surface. An extra foot or two can easily be folded under with most waterproof tarps.
2. Grommets or not?
Most waterproof tarps come with grommets that can be used to tie down the waterproof tarp by running rope through them. If you want to do this consider buying a waterproof tarp with ringed holes around all four edges, instead of just having grommets at the four corners. This will give you more mounting points and even pressure distribution across the waterproof tarp when tied down.
3. Material
When it comes to waterproof tarps there are two primary types: Polyethylene and Vinyl Coated Polyester (VCP).
Polyethylene is cheaper than VCP and is used for blue/black waterproof tarps that might be found at your local hardware store. These waterproof tarps are also usually waterproof to only 1-3 feet, depending on how stretched out they are when held under water. You can tell if the waterproof tarp is Polyethylene by checking for this stamp:
Vinyl Coated Polyester (VCP) waterproof tarps are much more expensive than the cheap blue waterproof tarps found at thrift stores, but offer waterproofing guarantees up to 6-12 feet of depth--depending on who you buy from and what their testing has shown. VCP waterproof tarps will have a gold/yellowish color with this stamp:
4. Grommet Type
A common problem with grommets is that they aren't attached to the waterproof tarp tightly and can come out, especially if you plan on mounting waterproof tarps in a high-traffic area. The simplest solution is to use grommets that slide into place after they've been tied down with some rope.
5. Stitches
Most waterproof tarps will have some sort of stitching around the edges so that it doesn't fray apart when cut or dragged across the ground. Look for waterproof tarps that are double-stitched along these areas.
6. Material Thickness
The thicker the waterproof tarp material, the more durable it will be over time and against heavy winds or tree branches falling on top of it. Make sure that the waterproof tarp isn't too thin though because then it will tear easily. Ideally waterproof tarps should be between 10-20 millimeters in thickness.
7. Tie-Down Loops
Some waterproof tarps have loops along the edge that are meant to be used for tying down the waterproof tarp with rope or bungee cords to make it tight against an object/surface. Look for waterproof tarps that have at least 1-2 of these loops at each corner, and more along the edges if possible (see picture below).
8. Waterproofing Guarantee
If you buy your waterproof tarp online there should be some sort of guarantee attached to it; otherwise you run the risk of getting a flimsy waterproof tarp that falls apart after only 2 weeks outside in the rain. Look for waterproof tarps that have a waterproofing guarantee of at least 6 months to 1 year, with 2-5 years being the ideal waterproof tarp lifespan.
9. Durability
Waterproof tarps are meant to be used outside, so they must be made of durable material. Unfortunately, waterproof tarps made out of Polyethylene are flimsier than Vinyl Coated Polyester waterproof tarps due to their smaller densities, which results in them being more easily torn apart over time by nature's elements. This isn't always true because some stores will sell cheap blue waterproof tarps that are both waterproof and durable—it just takes some trial and error to find these waterproof tarps since there is no stamp advertising which waterproof tarp is durable and which waterproof tarp is flimsy.
10. Price
Price shouldn't be the only deciding factor on whether or not you buy a waterproof tarp because there are some very cheap waterproof tarps that simply aren't worth buying—but there are also some high-quality waterproof tarps that cost more than $100, so try not to let price alone dictate your waterproof tarp choice.
Conclusion:
When buying waterproof tarps it's important to know what the waterproof tarp is made of, where/how it's waterproofed, and whether or not it has features that will be useful for your needs.
Blue waterproof tarps are perfect for camping or storing in your car just in case you ever need an emergency waterproof tarp; they aren't meant to last very long due to their low-quality material used, but most blue waterproof tarps cost less than $10 if bought brand new (some can cost even less). A cheap blue waterproof tarp might only last a few months outside before rips begin to form along the edges; however, if you're willing to pay more money then there are some waterproof tarps that are waterproof and durable, which will last up to 5 years outside.