Blue Rectangle Sun Shade Sail 17ft x 21ft - Custom Fit UPF50

Our review of the 17' x 21' blue rectangle sun shade sail finds it best suited for homeowners and small businesses who want a customizable, durable canopy that blocks sun and lowers temperatures. The single biggest reason to buy is its combination of heavy-duty 200 GSM HDPE fabric and 95% UV blockage, which delivers meaningful sun protection and cooler outdoor areas without feeling stifling. Installation is flexible enough for patios, play areas, or poolside shade, and the included reinforced corners and stainless steel D-Rings add real peace of mind.

Key Features

• 95% Sun Protection: The 200 GSM HDPE fabric blocks up to 95% of UV rays to protect skin and outdoor furniture from sun damage.
• Temperature Reduction: The mesh construction lowers surface and ambient temperatures by as much as 15 degrees compared with unshaded spots, making outdoor time more comfortable.
• Water and Air Permeable: The breathable material sheds some rain while allowing breezes to pass through, reducing wind load and pooling.
• Customizable Fit: The sail is made to order with exact D-ring to D-ring measurements so the canopy can be tailored to awkward or specific layouts.
• Durable Construction: Reinforced edges, double-layer stitching and stainless steel D-Rings improve longevity and resist fraying under regular use.
• Simple Installation Guidance: The product recommends leaving a 0.5 ft gap between D-Rings and poles (or reducing by 1 to 1.5 ft per side) to achieve correct tension during setup.

Who It's For

This shade sail is ideal for homeowners with patios, decks, pool areas or gardens who need a tailored rectangle canopy that balances sun protection and airflow. It also works for small commercial settings such as cafe terraces or playgrounds where a semi-permanent, breathable cover is preferred over solid awnings.

Those who should look elsewhere include buyers who need a fully waterproof or solid fabric canopy for heavy, sustained rainfall or snow load, or customers who want a pre-cut off-the-shelf size without placing a custom order and supplying precise D-ring measurements.

Pros & Cons

Pros

• High UV blockage up to 95% provides strong sun protection for people and furnishings.
• Breathable HDPE fabric lowers temperature up to 15 degrees, improving comfort under the sail.
• Stainless steel D-Rings and reinforced stitching add durability and simplify secure mounting.
• Custom sizing ensures a tailored fit for unusual spaces when D-ring to D-ring measurements are provided.

Cons

• One customer reported incorrect dimensions, so careful measurement and confirmation are important for custom orders.
• Not fully waterproof, so it will not replace a solid canopy where total rain protection is required.

Specifications

Material	200 GSM HDPE
Sun Protection	Up to 95% UV blockage
Size	Custom 17' x 21' rectangle
Permeability	Water and air permeable
Hardware	Stainless steel D-Rings; reinforced edges; double-layer stitching
Temperature Reduction	Up to 15 degrees vs unshaded areas
Assurance	3 year assurance included

Our Verdict

The 17' x 21' blue rectangle shade sail is a sensible buy for people seeking a robust, breathable canopy that delivers strong sun protection and a cooler outdoor space. Its customizable sizing, reinforced corners and stainless steel D-Rings make it good value for residential and light commercial use, provided you accept a breathable rather than fully waterproof cover.

Frequently Asked Questions

Is this sail waterproof?
The fabric is water and air permeable, so it sheds light rain but is not fully waterproof for heavy downpours.

How should I measure for a custom fit?
Measure from D-ring to D-ring for each corner and confirm dimensions with the seller; the sail is made to those exact measurements.

What hardware is recommended for installation?
Use sturdy posts, walls, or trees with appropriate mounting kits and maintain at least a 0.5 ft gap between D-Rings and poles for optimal tension; adjust as advised for each side.