Taimei

Q
How to Choose a Poly Tarp (Polyethylene PE Tarpaulin)?
A
How to choose a Poly Tarp (Polyethylene Tarpaulin)

Poly Tarps are one of the most popular tarps available to consumers due to the wide range of colors, sizes, weights/strength and price. This document will provide the information you need to select the right tarp for your application whether you are covering a canopy, carport, construction job, tent frame, outdoor event, yard project or wedding.

 

Poly Tarp Construction:

 

Poly Tarps are typically made of multiple layers with a woven mesh fabric sandwiched between two or more polyethylene sheets. (TARPMAX can make maximum 5 layers) Polyethylene is the same material used in cables, pipes and molded containers. It accounts for the largest portion of recycled plastics (recycle codes 1, 2 and 3). There are many other features that should be considered as well when evaluating your purchase. Consider the following list of tarp features before deciding on the right tarp for your application.

 

Ø  – This is the actual thickness of the tarp measured in mils (1/1000 of an inch). The larger the number, the thicker the tarp. Typical light weight blue tarps found in most retail or hardware stores are about 6 mils. If you are planning a heavy duty use, such as covering a carport, consider a heavy duty tarp at 11 to 12 mils or a super heavy duty tarp at 23 mils.

Ø  – The specified sizes of poly tarps will not be the actual measured size. The sizes will vary from one manufacturer to another. Be sure to check the descriptions for the tarps. Tarps will typically be 4 to 6 inches smaller in each direction than the specified size. If a tarp is specified to be 10 feet the actual size will be 9 ft 6 in to 9 ft 8 in. This is due to the fact that tarps are cut to size and then hemmed at the edges. The hem uses up some of the original width leaving the tarp slightly smaller than specified.

Ø  – Most poly tarps are constructed with a mesh fabric laminated between at least two layers of polyethylene film. Some heavy duty and super heavy duty tarps will have an additional layer of black polyethylene laminated in the center to prevent sun rays from penetrating the tarp. For some specially used, Tarpmax provide 5 layers lamination, it have strong water resistance ability.

Ø  – The mesh fabric specification is the number of threads per square inch. An 8X8 mesh count would mean there are an average of 8 threads per inch in both the horizontal and vertical direction. Heavier duty tarps will have from 12 to 16 threads per inch. The thread weight may also be specified in denier. Denier is the weight in grams of 9000 ft of thread. The larger the denier the heavier the thread. Denier is not always specified but generally the heavier duty the tarp the larger the thread.

Ø  – Grommets are metal rings lining a small hole at the edge of a tarp to accommodate the attachment of cords or bungees to the tarp. Spacing of grommets will vary from 18 inches to 36 inches depending on the grade of the tarp. Higher grade tarps will have the grommets spaced approximately 18 inches apart. Grommets may be made of aluminum (rust proof but not the strongest),brass (rust proof and strong), or plated steel (rust resistant and strong), and also plastic(Polycarbonate). The most durable and rustproof grommets for outdoor use are brass.

Ø  – Tarps may have additional reinforcement around the perimeter of the tarp to help prevent ripping and tearing. There are four main types of reinforcement.

o    Corner reinforcement – The higher the grade of tarp the more likely you will find heavy reinforcement in the corners. Corner reinforcement helps prevent tearing out of the corner grommets and will extend the life of your tarp.

o    Perimeter rope – This is a rope which has been sewn inside the hem at the edge of the tarp to add reinforcement strength to the tarp.

o    Hem – The hem is formed by folding the edge of the tarp back onto the tarp and then stitching the entire hemmed area. Most poly tarps have a hem.

o    Grommet reinforcement – In addition to the corners some tarps have additional reinforcement at each grommet sometimes called a patch. This reinforcement is added to the hem area of the tarp and is typically only available in the heaviest duty tarps. Note that some heavy duty tarps may use additional reinforcement in the hem to improve grommet strength and will not have the perimeter rope.

Ø  – This is a chemical treatment done when manufacturing the tarp to help protect degradation of the poly tarp from UV rays.

Ø  – Most poly tarps are waterproof. The laminated film layers of polyethylene are naturally waterproof. However, some screen poly tarps designed for truck bed covers and sun screens are not waterproof.

Ø  – Since polyethylene is water proof it also is resistant to rot and mildew.

Ø  – No poly tarp is flame-proof and should not be used near open flames or other heat sources. Some flame retardant tarps are available. If you are purchasing a flame retardant tarp, be sure you know and understand the specifications.

Ø  – Sun blocking tarps have an additional layer of black polyethylene and black mesh threads to form a light blocking tarp.

Ø  – Tarps come in a wide range of colors all of which will not be covered here. Some tarps have special features that may be required for your application.

o    Silver Sun Blocker – These specialty tarps are designed with black polyethylene and black mesh laminated between silver poly on one side and either a light or dark poly on the other depending on the manufacturer. The key feature of these tarps is that they block the sun light, and are cooler underneath in the summer. These tarps are great for canopies and carports.

o    White – These tarps are great in that they provide some shade but allow some natural light to come through. Applications include wedding receptions, dining canopies and vendor booths.

o    Clear – Clear poly tarps are great anywhere you need to have a lot of light but still need to have protection from the weather such as green houses.

o   Blue, Green, Brown – These tarps have no special color features but are great utility tarps for use in general construction or landscape maintenance.

 

o   These brightly colored tarps are used where high visibility is preferred.

 


Poly Tarp Comparison Table:

 

This table is intended to provide as a quick comparison of typical tarp features. It is not based on any know document or specification but was compiled from many online sources. Use this as a guideline not as an actual specification.

 

 

Light weight

Medium

Heavy duty

Super Heavy

 

 

Weight

 

Duty

  GSM

65-90gsm

95-110gsm

120-200gsm

260gsm Above

Thickness

5-6 mil

9-10 mil

11-12 mil

23–24 mil

Laminate

3

3

3-4

3-4

layers

 

 

 

 

Mesh Count

8 x 8 / sq in.

10 x 10 / sq in.

12 to 14 / sq in.

16x16 / sq in.

Mesh Denier

800

1000

1200

 

Weight (per

~2 to 3 oz.

~ 4.5 oz.

~6 oz.

~11 to 12 oz.

sq. yard)

 

 

 

 

Grommet

~18-36 inches

~18-36 inches

~18 inches

~18 inches

spacing

 

 

 

 

Grommet

Varies

Varies

Brass

Brass

type

 

 

 

 

Rope

Available

Available

Available

Hem reinforced

UV Treated

Available

Available

Available

Available

Waterproof

Yes

Yes

Yes

Yes

Rot resistant

Yes

Yes

Yes

Yes

Mildew

Yes

Yes

Yes

Yes

resistant

 

 

 

 

Uses