Tarps come in just about any size you can imagine. 4’x6′. 8’x’10’, 12′ x 20′, 24′ x 36” and 50′ x 100′ are just a few sizes out there. Materials are just as varied and the intended use should help you decide what material type to choose for your use. You will see blue colored plastic tarps sold just about everywhere.
They are cheap and give pretty good service over short periods of time. Covering an ongoing construction project from rain is an excellent use as long as you do not “skin” or damage the tarp during placement.
Even a small pinhole will allow an incredible amount of water to penetrate the tarp. Dragging these tarps over beams or boards while placing them can damage the surface of the tarp so placement by two people is always better than one. Any sharp edged object is a tarps enemy.
Choose a tarp as close to the size as you really need. Getting a 40′ x 50′ tarp for a 10′ x 12′ hole means you have to deal with all that extra tarp when handling it and also somehow have to anchor the rest of the tarp to prevent the wind from ripping the tarp away.
Many contractors consider the blue tarps disposable due to their inexpensive cost and easy availability. With careful handling you may get numerous uses thereby making the tarp cheaper and cheaper to use each time.
Properly anchoring the tarp is the number one item of importance. Improper anchoring will simply allow the tarp to either just blow away, whip itself to shreds in the wind or perhaps sag and collect tons of water which could collapse and destroy the work or injure the people working below.
If you were covering a 10′ x 12′ hole perhaps, by using lumber pieces to span the hole every two or three feet apart will provide support for the tarp. Placing sawhorses in the middle of each side of the hole, connecting them with a piece of lumber to form a high point over the hole and then placing the tarp will allow rainwater to shed off the tarp and away from the hole.
Anchoring the side edges is very important as well. Wood stakes driven into the ground or pieces of reinforcing bar are great tarp anchors if placed deep enough to resist the pull of the tarp in a good wind.
Placing a continuous 2″x4″ around the edge of the tarp, anchored to the stakes, also helps keep the tarp from getting free.
There are pre-made tarp anchors that allow you to grip the tarp in places where no grommet eyes exist and thereby allow you to add more anchors. These are cheap and reusable.
The other major tarp material is canvas. These tarps types are considerably more expensive and are considered for long term use. You will see them draped on the sides of high rise buildings on the scaffolding to prevent debris from flying out off the scaffolds to the street below.
Some are used as weather protection but all require special anchoring systems. The other big difference in these tarps is their weight. Two workers can easily handle a 40′ x 50′ plastic tarp without wind but a 40′ x 50′ heavy duty canvas tarp takes many more hands just to carry it. Lifting or spreading it is next to impossible.
The use of tarps is endless but by following the suggestions above for anchoring, you can safely use them for whatever you can think of around your home or work site.