ShadeMart 20ft x 21ft Blue Rectangle Sun Shade Sail - UPF50 Canopy

In this review the ShadeMart 20' x 21' Blue Sun Shade Sail is evaluated for homeowners and RV owners who need a large, breathable canopy that blocks sun and reduces temperature. The bottom line: this woven HDPE rectangle sail is built for long outdoor use and reliable UV protection, making it a sensible choice if you want a heavy duty, water-permeable cover rather than a waterproof tarp. The review focuses on fit, material quality, installation, and real-world performance.

Key Features

• Material: Woven HDPE fabric provides a durable, lightweight canopy that resists fading and sheds heat rather than holding moisture.
• UV Protection: UPF50 construction blocks up to 95% of harmful UV rays to noticeably lower temperatures beneath the sail.
• Breathability: The fabric is water permeable and allows air to pass through, reducing wind load and preventing pooling during rain.
• Hardware: Stainless steel D rings reinforced with heavy duty white webbing at corners improve attachment strength and longevity.
• Custom Sizes: A range of custom size options is offered so you can match the sail to patios, carports, pools, or RV covers when measured accurately.
• Styling: Rectangle shape and color choices let the sail integrate with existing outdoor design while serving as a decorative sun screen.

Who It's For

This shade sail is best for homeowners, RV owners, and small business operators who need broad UV protection and airflow rather than full waterproofing. It works well over patios, carports, pergolas and pools where shade and ventilation are priorities, and installers who want stainless steel corner hardware for secure anchoring will appreciate the reinforced webbing.

It is less suitable for buyers who need a fully waterproof shelter or who cannot accept small dimensional variance from manual measurement. If you require a tarp that keeps all rain out or need an exact, factory-cut dimension tolerance, consider a different waterproof cover or a rigid structure.

Pros & Cons

Pros

• Effective sun protection and heat reduction thanks to the UPF50 woven HDPE fabric.
• Durable build with stainless steel D rings and heavy duty webbing at attachment points.
• Breathable and water permeable design prevents water pooling and reduces wind stress.
• Easy to install in a variety of configurations with the proper hardware kit.

Cons

• Not waterproof, so it will not keep heavy rain out of a covered area.
• Some customers report mixed expectations on color and that manual measurement can produce slight size variations.

Specifications

Brand	ShadeMart
Shape	Rectangle
Size	20' x 21'
Material	Woven HDPE (High Density Polyethylene)
UV Rating	UPF50 (blocks up to 95% UV)
Corner Hardware	Stainless steel D rings with heavy duty white webbing
Water Resistance	Water permeable, not waterproof

Our Verdict

The ShadeMart 20' x 21' rectangle shade sail is a practical, value-minded choice for people who need strong UV protection and airflow across large outdoor areas. Its durable HDPE fabric and reinforced corners make it reliable for patios, carports, and RV covers, but buyers who need waterproof coverage or exact dimensional precision should consider alternatives.

Frequently Asked Questions

Is this shade sail waterproof?
The fabric is water permeable and breathable, so it will not keep all rain out and is not a waterproof tarp.

Can it be mounted to trees, poles, or a wall?
Yes, with the proper hardware kit the stainless steel D rings and webbing allow attachment to poles, trees, walls, and roofs.

Will the color fade in sun?
Customers generally report good color retention and durability, though some feedback is mixed on exact color match versus advertised shades.