A waterproof tarpaulin is a large sheet of thin waterproof material used for construction-related temporary shelters and other uses. Commercial, industrial and military applications exist. In these cases, the sheets are larger, have reinforcement grommets at regular intervals, reinforced corners and can be fitted with ropes or cables to secure them in place.
- Construction site shelter
- Demarcation on a construction site while re-routing traffic
- Emergency protection from rain while going through a “wet” area of the construction site
- Temporary road closure during night time
It can also be a one person tent that can be easily carried around by one person but provides adequate protection from light showers or sunrays. The manufacture of waterproof tarpaulins takes place in two primary ways. A “coated” material is made first by applying a polymer coating to the high-strength woven or felted material through either one or both sides. The “uncoated” sheets are only coated on one side. Then, after further processing, the sheeting can be sealed with heat so that it becomes entirely waterproof.
Uncoated material is also available but should have additional water resistant treatments applied before use for outdoor applications to increase durability and resistance to UV light, moisture or other types of degradation. Waterproofing applications that are used include spray-on coatings, laminating the product with polyethylene films, powder coating it with a silicone resin, and the use of hot air welding which melts a polymer film on to the material. These results in a very flexible monolithic product with non-directional properties that also has very high tear strength.
In commercial or industrial application, waterproof tarpaulins are manufactured from high-density polyethylene (HDPE), woven polyethylene, thick PVC, durable polyester fiber reinforced vinyl ester (PVF) or a specialty fabric such as aramid fibers. Most fabrics have UV inhibitors added to protect them from degradation due to sunlight.
Aramid is a synthetic fiber known for its high strength and heat tolerance. It is used as upper-body wear by firefighters as well as an armour plating material.
The fabric is waterproof, non-flammable and meets the requirements of NFPA 1975 for a garment to be worn by firefighters over structural fire fighting clothing that offers limited protection against heat and flame.
Origin of Tarpaulin
The word ‘tarpaulin‘ originated in the 17th century, from “Tarpal”, an abbreviation of “Saint-Léger Tarpaulin”. The name was later adopted by seafarers around the world. One origin is possibly a Dutch etymology stemming from Middle Dutch “tarpe” (“shelter”) + “oe” / -an. Another origin seems to point to early nineteenth century England where similar words are found: French “tarpau,” Spanish “trapo,” and Portuguese “tropa”, all of which mean roughly the same as English, and were probably derived from an unrecorded Old English word.
Sailors used the material to cover their boats as protection from the elements before modern waterproof fabrics such as Gore-Tex were invented. Tarpaulins for marine use are often made of cotton or nylon, and come in a variety of thicknesses. The very thin plastic sheeting used for greenhouse covers is sometimes called “tarpaulin”, but this usage is not universal.
Cotton tarpaulins must be impregnated with chemicals to make them waterproof and rot-proof; otherwise they would soon rot under rain or snow. Modern tarpaulins made of heavy polyethylene can be machine-washed and will remain waterproof. The plastic material used for the tarpaulins has UV inhibitors added to protect it from degradation due to sunlight.
Tarpaulin is also a common name in Australia and New Zealand, familiar as a synonym for “a tent” or “awning”, often shortened to ‘tarp’. Given that tarpaulins are so frequently called upon by campers and military personnel worldwide, one might expect this term to have widespread use elsewhere as well, but it does not—the production of tents and other enclosures having been monopolized by other words derived from Greek: παρέκκλινα (parekkline) in Modern Greek.