ShadeMart 16 ft x 21 ft White Sun Shade Sail UPF50 Rectangle

In this review the ShadeMart 16' x 21' White Sun Shade Sail is evaluated for homeowners and small businesses who need reliable sun protection without trapping heat. The bottom line: this rectangle shade sail is best for patios, carports, pools and pergolas where breathability and UV blocking matter most, because the woven HDPE fabric is water permeable, blocks up to 95% of harmful UV rays and noticeably lowers temperatures. Installation is straightforward with proper hardware, and the stainless steel D rings feel durable in use.

Key Features

• Woven HDPE fabric: provides a durable, breathable canopy that lets air and water pass through while blocking most sunlight to keep covered areas cooler.
• UPF50 sun protection: blocks up to 95% of harmful UV rays so furniture and skin are better protected from sun damage.
• Stainless steel corner D rings: attached to heavy duty white webbing to give secure anchor points that withstand normal outdoor stresses.
• Water permeable design: allows rain to pass through rather than pooling on the sail, reducing the risk of damage and sagging during wet weather.
• Custom size options: available in a wide range of sizes so shoppers can choose a sail that fits their space when measured accurately.
• Versatile mounting: with the right hardware the sail can be fixed to poles, trees, walls or roofs for multiple outdoor uses.

Who It's For

The ShadeMart rectangle shade sail is ideal for homeowners looking to cool patios, carports and poolside areas without a permanent structure; its breathability is good for hot, humid climates where airflow is important. It also suits renters or seasonal users who want an attractive, removable canopy with strong UV protection.

It is less suitable for anyone who needs a fully waterproof solution or a perfectly rigid structure; if you need complete rain protection or a tensioned frame that keeps a perfectly flat shape, consider a waterproof canopy or hard roof instead.

Pros & Cons

Pros

• High UPF50 protection significantly reduces sun exposure and lowers perceived temperature beneath the sail.
• Durable construction with stainless steel D rings and heavy webbing for reliable anchoring.
• Breathable, water permeable fabric prevents pooling and maintains airflow for comfort.
• Custom sizes and multiple colors make it adaptable to many outdoor designs.

Cons

• Not waterproof, so it will not provide full rain protection during heavy storms.
• Some buyers report mixed size and shape expectations, so careful measurement is required before ordering.

Specifications

Brand	ShadeMart
Shape	Rectangle
Size	16' x 21'
Material	Woven HDPE (High Density Polyethylene)
Sun Protection	UPF50 (blocks up to 95% UV)
Water Resistance	Water permeable, not waterproof
Hardware	Stainless steel corner D rings with heavy white webbing

Our Verdict

The ShadeMart 16' x 21' rectangle shade sail is a solid, value-minded choice for anyone wanting effective sun protection and cooler outdoor spaces without a rigid structure. Its breathable HDPE fabric, stainless steel hardware and UPF50 performance make it durable and practical for patios, carports and pool areas, provided you accept that it is water permeable rather than waterproof.

Frequently Asked Questions

Is this shade sail waterproof?
No. The fabric is water permeable and designed to let water pass through to avoid pooling.

Will it block UV and reduce heat?
Yes. The sail blocks up to 95% of harmful UV rays and typically lowers temperatures under the canopy.

Can it be mounted to trees or poles?
Yes. With proper hardware kits it can be attached to poles, trees, walls or roofs for many outdoor setups.