When shopping for tarps, you've probably noticed specifications mentioning "mil thickness" – but what does this actually mean for your project? Understanding mil thickness is crucial for choosing a tarp that will stand up to your specific needs without overpaying for unnecessary durability or underestimating what you'll need.
What is Mil Thickness?
Mil thickness refers to the measurement of a tarp's material thickness, where one mil equals one thousandth of an inch (0.001"). This isn't just a random number – it's a direct indicator of your tarp's strength, durability, and suitability for different applications.
Quick Reference:
-
1 mil = 0.001 inches
-
Higher mil = thicker material = greater durability
-
Typical range: 3 mil to 20+ mil for heavy-duty applications
Breaking Down Mil Thickness Categories
Light-Duty Tarps (3-6 mil)
Best for:
-
Temporary ground covers
-
Light gardening protection
-
Indoor storage covers
-
Short-term outdoor use (1-3 months)
Pros: Light-duty tarps are ideal for quick, temporary tasks where portability and ease of use are key. Their lightweight nature makes them easy to fold, transport, and set up, even by one person. They're cost-effective for projects that don’t require long-term durability, making them a go-to option for homeowners and gardeners. These tarps are also available in a variety of sizes and colors, offering flexibility for casual or light-duty needs.
Cons: Due to their thinner material, these tarps can easily tear or puncture under stress or in harsh weather. They offer minimal UV protection and can degrade quickly with prolonged sun exposure. Light-duty tarps are not suitable for heavy-duty applications, windy environments, or extended outdoor storage, as they lack the strength and weather resistance needed for such conditions.
Medium-Duty Tarps (6-10 mil)
Best for:
-
Camping and outdoor activities
-
Moderate weather protection
-
Construction site covers
-
Boat and vehicle covers
-
Seasonal use (3-12 months)
Pros: Medium-duty tarps offer a great balance between strength and affordability, making them ideal for a wide range of general-purpose outdoor and indoor uses. They are typically made from polyethylene or poly-blend materials that provide decent resistance to water, UV rays, and mild abrasion. These tarps are lightweight enough to be portable but durable enough to handle variable weather conditions and moderate use. Their versatility makes them popular for both recreational and job site needs.
Cons: While stronger than light-duty tarps, medium-duty tarps may still fall short in extreme conditions such as high winds, heavy snow, or prolonged sun exposure. They can wear out faster when exposed to sharp edges or rough surfaces and may not offer the same level of tear resistance or waterproofing as heavier grades. Over time, UV degradation can cause the material to become brittle if left exposed for extended periods.
Heavy-Duty Tarps (10-16 mil)
Best for:
-
Long-term outdoor storage
-
Construction and industrial use
-
Truck covers and cargo protection
-
Swimming pool covers
-
Multi-year applications
Pros: Heavy-duty tarps offer excellent tear resistance, making them ideal for rugged environments and repeated use. Their strong UV protection ensures materials and equipment underneath are shielded from sun damage over extended periods. These tarps are also highly weather-resistant, capable of withstanding heavy rain, wind, and moderate snow, making them reliable for year-round outdoor applications. Their durability makes them a cost-effective choice for users who need long-term performance without frequent replacement.
Cons: Due to their thickness and strength, heavy-duty tarps are significantly heavier and more cumbersome to handle compared to lighter options. This can make installation and transport more labor-intensive, especially for large sizes. Additionally, their higher cost may not be ideal for short-term or casual use, where a lighter-duty tarp would suffice. While they excel in durability, the initial investment and added weight may be drawbacks for users seeking convenience or on a tight budget.
Extra Heavy-Duty Tarps (16+ mil)
Best for:
-
Extreme weather conditions
-
Industrial and commercial applications
-
Permanent or semi-permanent installations
-
High-abrasion environments
Pros: Extra heavy-duty tarps offer maximum durability, making them ideal for withstanding harsh environments with a high resistance to tears, punctures, and abrasions. They provide superior weather protection, shielding against intense UV rays, heavy rain, snow, and strong winds, making them perfect for long-term outdoor use. Their rugged construction contributes to the longest lifespan among tarp types, offering excellent long-term value. Additionally, these tarps often feature reinforced elements such as heavy-duty grommets, thick hems, and high-tensile materials, enhancing their strength and ensuring secure fastening even in challenging conditions.
Cons: The advanced features and premium build quality of extra heavy-duty tarps come at a higher upfront cost, making them the most expensive option. Their substantial weight also makes them more difficult to handle, transport, and install, often requiring additional labor or equipment. Moreover, the material can be less flexible—especially in colder temperatures—which may limit ease of use in smaller or short-term applications.
Factors Beyond Mil Thickness
While mil thickness is important, it's not the only factor determining tarp quality:
Material Type
-
Polyethylene (PE): Most common, good water resistance
-
Vinyl: Superior durability, excellent for long-term use
-
Canvas: Breathable, ideal for covering items that need air circulation
-
Mesh: Allows airflow while providing shade and protection
Weave and Coating
The tarp's weave pattern and any protective coatings significantly impact durability. Look for:
-
Reinforced edges and corners
-
UV-resistant coatings
-
Waterproof treatments
-
Mildew-resistant properties
Grommet Quality
Heavy-duty brass or stainless steel grommets prevent tearing at attachment points – crucial for long-term use.
How to Choose the Right Mil Thickness
Step 1: Assess Your Environment
-
Indoor use: 3-6 mil usually sufficient
-
Moderate outdoor conditions: 6-10 mil
-
Harsh weather/long-term: 10+ mil
-
Extreme conditions: 16+ mil
Step 2: Consider Duration
-
Temporary (days-weeks): Lower mil acceptable
-
Seasonal (months): Medium mil recommended
-
Long-term (years): Higher mil essential
Step 3: Factor in Handling
-
Frequent setup/takedown: Medium mil for durability without excessive weight
-
Permanent installation: Higher mil for longevity
-
Occasional use: Balance cost vs. expected lifespan
Step 4: Budget Considerations
Remember: investing in appropriate mil thickness upfront often saves money long-term by avoiding replacements.
Common Mistakes to Avoid
-
Choosing based on price alone – A cheap tarp that fails quickly costs more than a properly-rated one
-
Over-specifying – Don't pay for 16 mil when 10 mil meets your needs
-
Ignoring environmental factors – UV exposure, temperature extremes, and wind affect durability
-
Focusing only on mil thickness – Material quality and construction matter too
Real-World Application Examples
Homeowner covering a woodpile: 6-8 mil polyethylene tarp with UV coating – provides good protection without excessive cost.
Construction site equipment cover: 12-14 mil reinforced tarp – handles weather, debris, and regular handling.
Long-term boat storage: 16+ mil vinyl tarp – withstands marine environment and provides years of protection.
Emergency roof repair: 6-10 mil depending on expected repair timeline – temporary but reliable protection.
Making Your Decision
The right mil thickness depends on your specific needs, but here's a quick decision framework:
-
Light use, short-term: 3-6 mil
-
Regular use, moderate conditions: 6-10 mil
-
Heavy use, challenging conditions: 10-16 mil
-
Extreme conditions, permanent use: 16+ mil
Conclusion
Understanding mil thickness empowers you to make informed tarp purchases that match your specific requirements. By considering your environment, duration of use, and budget alongside mil thickness specifications, you'll choose a tarp that provides reliable protection without overspending.
Whether you need a light-duty cover for weekend projects or a heavy-duty solution for long-term industrial use, the right mil thickness ensures your investment delivers the performance you expect.
For expert guidance on selecting the perfect tarp for your specific needs, Tarp Supply Inc.® offers comprehensive product knowledge and quality solutions across all mil thickness categories. Their experienced team can help you navigate the options and find the ideal balance of durability, functionality, and value for your project.
