Overview
The most common disappointment with shade sails is not quality—it's timing: the shade ends up in the wrong place at the wrong hour.
You don't need complicated software to avoid this. With a few simple rules about how the sun moves, you can predict where shade will fall and design a sail that works when you actually use the space.
1. The Only Sun Path Rules You Really Need
The sun does the same basic things everywhere:
- It rises roughly in the east, sets roughly in the west.
- It's higher in the sky in summer and lower in winter.
- At mid-day, it's roughly to the south in the northern hemisphere.
Shade always falls on the opposite side of the object from the sun. For a sail, that means:
Where the sun is → shade moves to the opposite side of the sail.
2. Find Your Directions (No Fancy Tools Needed)
You need a rough idea of north, south, east, and west. You can use:
- a phone compass
- the sun at noon (it's roughly south in the northern hemisphere)
- satellite view in any map app
Quick orientation sketch:
- Draw a simple rectangle for your patio or yard.
- Mark the house wall and any boundaries.
- Add arrows showing east (sunrise), south (mid-day), and west (sunset).
This sketch becomes your "mini shade simulator" for the next steps.
3. Start With When You Actually Use the Space
Instead of trying to shade all day long, pick your real priority:
- Morning coffee? 8–10 AM.
- Mid-day lunches? 12–2 PM.
- Late afternoon / after work? 4–7 PM.
The sail cannot be perfect for every hour, but it can be excellent for the hours that matter most.
Simple rule: "If I care about shade at 5 PM, I design for late-day sun, not 1 PM sun."
4. How Shade Moves: Morning vs Mid-Day vs Evening
Morning (sun in the east)
- Sun is low in the east.
- Shade stretches long toward the west.
- A sail placed on the east side of a sitting area will not help much—shade will fall behind it.
Mid-Day (sun high, to the south)
- Sun is nearly overhead (higher in summer, lower in winter).
- Shade falls almost directly underneath the sail.
- A reasonably centered sail works well for lunch hours.
Late Afternoon / Evening (sun in the west)
- Sun is low in the west.
- Shade stretches long toward the east.
- If most use is after work, sails should be biased slightly west of the area you want shaded.
5. A Simple "String & Shadow" Modeling Trick
You can preview shade behavior using almost no tools:
- At the time you care about (for example, 5 PM), go outside.
- Hold a stick, broom, or pole roughly where a sail corner would be.
- Notice where the shadow falls at that time of day.
- Repeat with a couple of positions to see how shade "moves."
You're essentially using the actual sun as your modeling tool, instead of guessing.
6. How Sail Height Changes Shade Reach
The higher the sail, the farther its shade reaches when the sun is low. When the sun is high, height matters less.
Effects of raising the sail:
- Shade becomes larger but softer at the edges.
- In early morning and late afternoon, shade stretches farther.
- Wind exposure increases slightly.
Effects of lowering the sail:
- Shade becomes more defined but covers a smaller ground area.
- Better for blocking glare through windows.
- Less wind exposure but may feel visually "heavy."
This is where post height planning comes in—pair this with the Post Placement & Height Strategy guide.
7. Example Layouts for Common Goals
Goal: Shade a West-Facing Patio in the Late Afternoon
- Most heat and glare arrive from the west.
- Place the sail slightly west of the seating area.
- Make the western anchors higher; eastern anchors lower.
- This tilts the shade "down" over your patio as the sun drops.
Goal: Mid-Day Kids' Play Area Shade
- Sun is high; direction is less extreme.
- Center the sail over the play area.
- Use moderate height for even coverage.
- Consider overlapping two sails if the area is wide.
Goal: Lunch Table Shade Near a South-Facing Wall
- Sun is mostly from the south at mid-day.
- Mount some anchors on the wall and some on posts.
- High anchors on the wall, lower anchors farther out.
- This blocks direct sun from striking people at the table.
8. Seasonal Changes: Summer vs Winter
In summer, the sun is higher. In winter, it's lower and more "sideways."
What this means for shade:
- Summer: shade sits closer under the sail.
- Winter: shade stretches farther from the sail, especially mornings and evenings.
If you live in a region with hot summers but cool winters, many people design for summer comfort first, and accept that winter shade behavior will be different.
For seasonal tuning, see the Seasonal Adjustments guide.
9. The Most Common Shade Planning Mistakes
- Designing for "all day shade" instead of key hours.
- Ignoring west sun, which is often the hottest and harshest.
- Placing the sail directly above the target area without considering time of day.
- Setting the sail too low for late-day shade reach.
- Not sketching orientation at all.
Correcting these on paper first is far easier than moving posts or reordering sails later.
10. Quick Shade Modeling Checklist
- I know roughly where north, south, east, and west are.
- I picked my most important use time (morning, mid-day, or late afternoon).
- I placed the sail so shade falls where I need it at that time.
- I considered height so shade reaches far enough when the sun is low.
- I understand that shade will move throughout the day—and that's normal.
Next Steps
Once you understand how the sun moves, the rest of the project is about safe, stable installation. These guides connect directly to what you've just learned: