How Do I Decide What Greenhouse Cover Thickness I Need?

Greenhouse cover thickness is a critical feature of your polyethylene cover, and growers unsure of the thickness they need should consult experienced and knowledgeable professionals.

Greenhouse covers are typically offered in a range from 3 mil – 12 mil, with the most common greenhouse cover thickness being 6 mil. It’s important to note that, when it comes to plastic sheeting, “mil” is not a millimeter, but a unit of measurement equalling one one-thousandth of an inch. For instance, .006 could also be read as 6 mil. An Imperial millimeter is approximately 39 mils thick. A thickness gauge can help you determine the thickness of your plastic sheeting.

What Thickness Does My Greenhouse Cover Need to Be?

Generally, the strength of the plastic will go up the thicker the plastic is. Many factors determine how thick your plastic sheeting should be, with some of the most common factors being the material of the frame, the application of the sheeting, and the expected weather conditions. Consult an expert to help evaluate your specific growing conditions.

Frame Material

If your greenhouse is built from weaker material like PVC and the plastic sheeting material is too heavy, the structure will collapse, especially in the event of strong weather.  Thicker films should be used on wood or metal structures. When considering frame materials, growers should consider that PVC or polyester frames can react chemically with polyethylene sheeting, resulting in faster erosion.

Weather Conditions

Thicker plastic sheeting should be used where the weather conditions are less mild and the greenhouse is subject to heavy snow, rain, or heat. It’s also important to consider the installation of leak diverter drain tarps to help make sure you mitigate excess water leakage if you live in an especially wet area. Growers should keep in mind that, in hot weather conditions, metal frames can cause added friction to plastic, or cause plastic to melt. Regardless of frame materials, applying a felt barrier can reduce the deterioration of plastic sheeting.

Application

Thinner plastic sheeting should be used for general applications, like creating temporary walls and covering materials. Medium-thickness plastic can be used as greenhouse covers and enclosures. The thickest of sheeting can be preserved for heavy duty applications, such as water retention liners.

Does Greenhouse Cover Thickness Have Anything to Do With Longevity?

Thickness is not the only factor that contributes to longevity in plastic sheeting. Thickness correlates with durability. UV inhibitors and string reinforcement are features that can lengthen the life of your greenhouse cover. As a general gauge, 3 or 4 mil film is common for one year use on narrow tunnels and overwintering houses.

String reinforced sheeting can increase durability without increasing thickness, lengthening the life of your greenhouse cover.  If additional strength is needed, such as in high wind locations, a woven poly or nylon scrim-reinforced material should be considered. If sheeting tears, growers can quickly and inexpensively repair it with greenhouse tapes, like Reinforced Greenhouse Repair Tape or Heat Shrink Tape.

Americover is the premiere plastic sheeting provider for the West Coast. Growers can get the most for their dollar by choosing the right cover for their unique needs, by paying attention to the cleanliness of the cover, and by maintaining the frame. Growers can ensure that they have the best materials when they consult our experts with over 30 years of experience.

Learn more about 6 Mil Tuff-Scrim™ White Reinforced Poly Sheeting	Learn more about Reinforced Greenhouse Repair Tape	Learn more about Heat Shrink Wrap

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Americover is the smart source for plastic and polyethylene sheeting. Trusted by contractors and distributors across construction and agriculture industries, our American-made products combine reliability with quality and innovation. 

As an Americover customer, you will receive the personalized support of a dedicated account manager to simplify the ordering process and ensure the best solution for every one of your projects. Our friendly, knowledgeable staff is here to answer your questions and fulfill orders Monday-Friday from 7 a.m. to 4:30 p.m. Pacific Standard Time. If you would like to speak with a representative, call us at 760-388-6294 or contact us.