How to Measure for Outdoor Blinds: Inside Fit vs Outside Fit

Description

Measuring outdoor blinds correctly is critical for performance, longevity, and appearance. Whether you’re installing ZIP blinds, outdoor mesh blinds, clear PVC blinds, or track-guided systems, the way you measure will determine how well the blind handles wind, rain, sun, and daily use.

In this guide, we cover:

• The difference between inside fit and outside fit outdoor blinds

• Step-by-step instructions for measuring each option

• Common mistakes to avoid

• Pro tips for DIY and supply-only installs

Why Correct Measuring Matters for Outdoor Blinds

Outdoor blinds are not soft furnishings — they are structural systems. Incorrect measurements can lead to:

• Wind movement and noise

• Poor weather sealing

• Gaps at the sides or bottom

• Track misalignment

• Reduced lifespan of the blind

Measuring properly ensures:

• Better wind resistance

• Cleaner aesthetics

• Smooth operation

• Correct track engagement

Inside Fit vs Outside Fit: What’s the Difference?

Inside Fit Outdoor Blinds

Inside-fit blinds are mounted within the opening, fixing between posts, beams, or walls.

Best for:

• Clean, flush finishes

• Sheltered pergolas

• Areas with minimal wind exposure

• When you don’t want blinds visible from the outside

Key consideration:
Inside fits require very accurate measuring and solid fixing surfaces.

Outside Fit Outdoor Blinds

Outside-fit blinds are mounted over the opening, fixing to the face of beams, posts, fascia, or walls.

Best for:

• Maximum weather protection

• Wind-prone locations

• Larger openings

• Better sealing and coverage

Key consideration:
Outside fits are more forgiving and generally offer better performance.

How to Measure for Inside-Fit Outdoor Blinds

Step 1: Measure the Width

• Measure the opening inside to inside

• Measure at:

  • Top

  • Middle

  • Bottom

• Use the narrowest measurement

This ensures the blind will fit without binding.

Step 2: Measure the Drop (Height)

• Measure from the top inside fixing point down to the floor or deck

• Measure both sides

• Use the shortest drop

This avoids the blind catching on uneven ground or sloping decks.

Step 3: Check Fixing Surfaces

Confirm:

• Solid timber, steel, or aluminium fixing points

• Enough face width for side tracks (typically 65–100mm, system dependent)

Step 4: Check Internal Clearance

Look for:

• Sliding doors

• Door handles

• Light fittings

• Heaters

• Posts inside the opening

Allow at least 80–100mm clearance in front of doors or handles where required.

Step 5: Confirm Mounting Position

Inside-fit blinds can:

• Mount flush with the beam

• Mount slightly “above” the opening (often 50–100mm)

This affects headbox clearance and visual finish.

How to Measure for Outside-Fit Outdoor Blinds

Step 1: Measure the Width

• Measure outside to outside where the blind will fix

• Measure:

  • Top

  • Middle

  • Bottom

• Use the widest measurement

👉 Do not deduct anything.

Step 2: Measure the Drop (Height)

• Measure from the top fixing surface (beam or fascia)

• Down to the ground or deck

• Measure both sides

• Use the longest drop

Always allow for:

• Deck fall

• Uneven paving

• Drainage slope

Step 3: Confirm Fixing Surfaces

Ensure:

• Solid fixing material (timber, steel, aluminium)

• Enough face width for:

  • Tracks

  • Guide rails

  • Brackets

Step 4: Allow for Overlap

For best performance:

• Overlap the opening by 50–100mm per side

• Improves:

  • Wind resistance

  • Weather sealing

  • Visual finish

Step 5: Check External Obstructions

Check for:

• Downpipes

• Lights

• Heaters

• Handrails

• External doors

Measure around obstructions, not through them.

Common Measuring Mistakes to Avoid

• Measuring fabric size instead of total system size

• Deducting width or height incorrectly

• Measuring inside when ordering an outside fit

• Ignoring deck slope or ground fall

• Forgetting track and fixing clearance

• Mixing inside-fit and outside-fit logic

Pro Measuring Tips (Highly Recommended)

• Measure in millimetres (mm) only

• Use a steel tape measure

• Measure twice (or three times)

• Take photos of each opening

• When unsure, outside fit is usually safer

Inside Fit or Outside Fit: Which Should You Choose?

Final Thoughts

Correct measuring is the foundation of a successful outdoor blind installation. Whether you choose inside fit or outside fit, following the correct method will ensure your outdoor blinds perform as intended and last for years.

If you’re ordering supply-only outdoor blinds, accurate measurements are essential — there’s no room for guesswork.