Black Tarps Heavy Duty Waterproof 20x40 - 12 Mil Thick Durable Tarp

In this review of the Black Tarps Heavy Duty Waterproof 20x40 tarp, the bottom line is simple: this is a workhorse cover for anyone who needs reliable weather protection without a high price tag. The tarp's single biggest selling point is its sturdy 12 mil thickness paired with heat sealed seams and anti-rust grommets, which together deliver practical waterproofing and long-term use for outdoor gear, shelters, and temporary repairs. For homeowners, campers, and small contractors looking for tough, no-frills coverage, this tarp is worth considering.

Key Features

• 12 mil thickness: Provides a noticeably heavier feel and resistance to punctures compared with thin polyethylene tarps, making it suitable for repeated outdoor use.
• 100% virgin polyethylene: Ensures durability and reduces unpleasant chemical smells so the tarp can be used in enclosed temporary shelters or over stored items.
• Heat sealed seams: Prevents water from seeping through stitched edges, enhancing overall waterproof performance in storms and heavy rain.
• Anti-rust grommets every 20 in: Allow secure tie-downs and frequent anchoring points, useful for lashing the tarp over boats, roofs, and equipment.
• All-weather protection: UV resistance and weatherproof material mean the tarp can be left outdoors season after season without immediate breakdown.

Who It's For

This tarp suits homeowners, campers, and small contractors who need an affordable, heavy-duty cover to protect vehicles, outdoor furniture, sheds, and temporary shelters. Its 20x40 size and reinforced grommets make it practical for covering large items or creating a quick shelter when camping.

Those who need a perfectly sized, precision-cut industrial tarp or a warranty-backed commercial-grade tarp for continuous daily use in extreme environments may want to consider specialty tarps instead. Also, buyers expecting exact alternate sizes should double-check measurements, as some customers reported size inconsistencies.

Pros & Cons

Pros

• Thick 12 mil construction gives reliable puncture and tear resistance compared with thin consumer tarps.
• Heat sealed seams and waterproof polyethylene keep water out of sheds and covered items.
• Frequent anti-rust grommets make securing the tarp straightforward and adaptable to many setups.

Cons

• Some users report grommets or seams can fail under extreme tension, so heavy-duty anchoring should be monitored.
• Size reports are mixed, so buyers should confirm fit for precise applications.

Specifications

Size	20 ft x 40 ft (nominal)
Thickness	12 mil
Material	100% virgin polyethylene
Weight	180 grams per square meter
Weave count	1414
Grommet spacing	Every 20 in with anti-rust finish
Seams	Heat sealed

Our Verdict

The Black Tarps 20x40 12 mil tarp is a practical choice for users who need weatherproof, heavy-duty coverage without specialty pricing; its thick polyethylene, sealed seams, and frequent grommets deliver good value for general outdoor protection. It is best for homeowners, campers, and light contractors, while those who require industrial-grade guaranteed grommet performance or absolute size precision should consider higher-end options.

Frequently Asked Questions

Is this tarp fully waterproof?
Yes, the tarp has heat sealed seams and waterproof polyethylene construction designed to keep water out in normal rain and storm conditions.

How close are the grommets spaced?
Grommets are placed every 20 in and are treated to resist rust for secure tie-downs over time.

Will the tarp have a strong plastic smell?
The tarp is made from virgin polyethylene and is noted to have no unpleasant smell compared with cheaper alternatives.