ShadeMart 21 ft x 24 ft Green Sun Shade Sail Rectangle - UV Blocking

In this review of the ShadeMart 21' x 24' green rectangle shade sail, the bottom line is simple: this is a robust, breathable canopy for people who want reliable sun protection without trapping heat. The reviewer found it best for patios, carports and RV covers because the woven HDPE fabric blocks up to 95% of UV while remaining water and air permeable, so it lowers temperature under the sail. Installation requires appropriate hardware, but the heavy duty webbing and stainless steel D rings make anchoring straightforward for most DIYers.

Key Features

• Woven HDPE fabric: Provides durable UV protection while remaining breathable so heat and moisture do not build up underneath.
• Stainless steel D rings: Corner hardware resists corrosion and gives strong attachment points for long-term outdoor use.
• Water and air permeable: The sail sheds wind load by letting air pass through and allows rain to drip through instead of pooling.
• Blocks up to 95% UV: Significantly reduces direct sunlight and lowers temperatures by roughly 10 to 15 degrees under the canopy.
• Custom sizing available: Multiple size options and custom cuts let you fit odd-shaped patios, carports, or pool areas when measured carefully.
• Rectangular styling: Simple shape integrates with many outdoor designs and can be tensioned between trees, poles or building anchors.

Who It's For

This shade sail is aimed at homeowners and RV owners who need heavy duty sun protection for a patio, carport, pergola or poolside area and who prefer a breathable, nonwaterproof canopy that reduces heat. It is also suited to seasonal outdoor spaces where airflow and UV blocking matter more than rainproof coverage.

People who need a fully waterproof shelter, or who expect continuous torrential rain protection, should look for a waterproof awning instead. Also, buyers who need an exact color match should be aware color shades can vary slightly and some customers reported mixed opinions on the advertised tone.

Pros & Cons

Pros

• Excellent UV blocking and noticeable temperature reduction beneath the sail.
• Durable construction with woven HDPE and stainless steel D rings for solid anchoring.
• Breathable and water permeable design reduces wind stress and pooling from light rain.
• Custom size options make it flexible for many outdoor configurations.

Cons

• Not waterproof, so it will not provide full rain protection during heavy storms.
• Color and exact measurements can vary slightly due to manufacturing and manual measurement.

Specifications

Brand	ShadeMart
Shape	Rectangle
Size	21' x 24'
Material	Woven HDPE (High Density Polyethylene)
Corner Hardware	Stainless steel D rings on heavy duty webbing
Weather Performance	Water and air permeable, not waterproof
UV Protection	Blocks up to 95% of harmful UV rays

Our Verdict

The ShadeMart 21' x 24' green rectangle shade sail is a practical, value-focused choice for anyone needing effective sun protection with airflow. It combines sturdy HDPE fabric and stainless fittings to deliver long-lasting shade that cuts UV and lowers temperatures, making it a sensible buy for patios, carports and RV covers as long as you do not require full waterproofing.

Frequently Asked Questions

Is this shade sail waterproof?
No, the fabric is water permeable and breathable by design, so it will not be fully waterproof in heavy rain.

How does it attach to structures?
The sail uses stainless steel D rings attached to heavy duty webbing and can be tethered to poles, trees, walls or roof anchors with the proper hardware kit.

Will it reduce temperature under the sail?
Yes, the HDPE weave and UV blocking reduce direct sunlight and typically lower temperatures by about 10 to 15 degrees beneath the canopy.