ShadeMart 17 ft x 21 ft Turquoise Rectangle Sun Shade Sail - UPF50

Our review of the ShadeMart 17' x 21' Turquoise Sun Shade Sail finds it best for homeowners and small-business owners who want a durable, breathable shelter that cuts heat and UV without trapping moisture. The single biggest reason to buy is the woven HDPE fabric that blocks up to 95% of harmful UV rays while remaining water and air permeable, so it lowers temperatures and resists wind stress in summer storms. The review focuses on real-world use on patios, carports and pool areas where coverage, material quality and simple installation matter most.

Key Features

• Woven HDPE fabric: provides strong UV blocking and tear resistance while staying breathable so rain drains through instead of pooling.
• Stainless steel D rings: are attached to heavy duty white webbing at the corners for secure anchor points and longer corrosion resistance outdoors.
• Water and air permeable: allows airflow to reduce temperature by at least 10 to 15 degrees in direct sun while avoiding the flapping and strain that trapped water would cause.
• Custom size options: a wide range of sizes is offered so buyers can match odd-shaped patios, pergolas or carports when measured carefully.
• Rectangle styling: a clean, versatile shape that integrates with many outdoor designs and can be combined with multiple colors for layered shade.

Who It's For

The ShadeMart rectangle sun sail is ideal for homeowners, renters with permission to attach hardware, and small businesses that need economical, long-lasting shade for a patio, pool area or carport. People who value breathability and UV protection over full waterproofing will appreciate the fabric that lets water pass through and reduces peak temperatures.

Those who need complete rainproof coverage or who cannot install anchor points should look elsewhere; this style is explicitly not waterproof and requires proper hardware and attachment points like poles, trees or building anchors for best performance.

Pros & Cons

Pros

• Blocks up to 95% of UV rays, meaning much cooler outdoor spaces in strong sun.
• Durable woven HDPE construction that customers report holds up through summer storms.
• Stainless steel corner D rings and heavy webbing provide secure, corrosion-resistant anchors.
• Breathable design prevents water pooling and improves airflow compared with solid canopies.

Cons

• Not waterproof, so it will not keep out heavy rain or create a dry area beneath during downpours.
• Shade sails require accurate measurement and proper hardware for a neat, tensioned install; manual size variance may occur.

Specifications

Brand	ShadeMart
Shape	Rectangle
Size	17' x 21'
Material	Woven HDPE (High Density Polyethylene)
UV Protection	Blocks up to 95% of UV rays (UPF50)
Corner Hardware	Stainless steel D rings with heavy duty white webbing
Functionality	Water and air permeable, not waterproof

Our Verdict

The ShadeMart 17' x 21' rectangle shade sail is a solid value for anyone needing breathable, high-UV protection coverage for outdoor living spaces. Its durable HDPE fabric and stainless corner hardware make it well suited to patios, pools and carports, provided you accept that it is not waterproof and will need correct anchoring and measurements for a tidy install.

Frequently Asked Questions

Is this shade sail waterproof?
No. The fabric is water permeable and designed to let water pass through; it is not a waterproof canopy for rain protection.

Will the corners rust?
The corner D rings are stainless steel and attached to heavy white webbing, so they resist corrosion under normal outdoor conditions.

Can I order a different size?
Yes. ShadeMart offers a range of custom sizes, but measure your venue accurately because manual measurements can vary.