How to Install Venetian Blinds: Complete DIY Installation Guide

Installing venetian blinds is a satisfying DIY project that can save you significant money compared to professional installation. With the right preparation and attention to detail, most homeowners can achieve professional-looking results in just an hour or two per window.

Having installed thousands of blinds over my career, I've developed a foolproof method that works for beginners. This guide will walk you through every step, from unpacking to final adjustments.

Before You Begin

Gather Your Tools

You'll need the following tools for a smooth installation:

• Power drill with drill bits
• Phillips head screwdriver (or drill bit)
• Pencil for marking
• Steel tape measure
• Spirit level
• Step ladder
• Safety glasses
• Wall plugs (if drilling into masonry)

Check Your Package

Before starting, unpack your blinds and verify all components are present:

• Headrail with blinds attached
• Mounting brackets (typically 2-3 depending on blind width)
• Screws appropriate for your mounting surface
• Hold-down brackets (for outside mount)
• Cord cleat (for safety)

Inside Mount Installation

Inside mount installation places the blind within the window recess, creating a clean, built-in appearance. This method requires accurate measurements and a reasonably square window frame.

Step 1: Position the Brackets

Hold the headrail inside the window recess where it will sit when installed. The front of the headrail should be flush with the front of the window frame for the neatest appearance.

For blinds up to 900mm wide, you'll typically have two brackets—one near each end. Wider blinds will include a centre support bracket.

Position the end brackets approximately 50-75mm from each end of the headrail. The centre bracket (if included) should be positioned exactly in the middle.

Step 2: Mark Screw Holes

Hold each bracket in position against the top of the window recess (for top-fix) or against the side of the recess (for face-fix). Using a pencil, mark the screw hole positions through the bracket holes.

Use a spirit level to ensure brackets will be level with each other. Even a slight discrepancy can cause the blind to hang unevenly.

Step 3: Drill and Secure Brackets

For timber frames: Use a drill bit slightly smaller than your screws to create pilot holes. This prevents the timber from splitting. Screw the brackets firmly into place.

For masonry or plasterboard: Use an appropriate drill bit for your wall type. Insert wall plugs, then secure the brackets with screws.

Ensure all brackets are firmly fixed with no movement. Loose brackets will cause problems with blind operation.

Step 4: Mount the Headrail

With all brackets secured, it's time to mount the headrail. Most venetian blind brackets use a clip-in system:

• Tilt the front of the headrail upward
• Hook the back of the headrail into the rear of the brackets
• Push the front of the headrail up until it clicks into place

You should hear a distinct click when the headrail is properly seated in each bracket. Test by gently pulling down on the headrail—it should feel secure.

Outside Mount Installation

Outside mount installation fixes the blind to the wall or window frame above the recess. This is ideal for shallow recesses or when you want the blind to appear larger than the actual window.

Step 1: Determine Position

Decide exactly where you want the blind positioned. Consider:

• How far above the window recess the headrail will sit (typically 50-100mm)
• How much overlap you want on each side of the recess
• Any obstructions such as architraves or light fittings

Mark the top of where the blind will sit with a light pencil line, checking it's level with a spirit level.

Step 2: Position the Brackets

For outside mount, brackets typically fix through the back (against the wall) rather than the top. Position them at the height marked in Step 1, spaced according to the headrail width.

Mark all screw holes with a pencil.

Step 3: Fix the Brackets

The method depends on your mounting surface:

Timber architrave or frame: Drill pilot holes and screw directly into the timber.

Plasterboard: Use appropriate wall plugs or toggle bolts for secure fixing. Standard plugs may pull out over time under the weight of the blind.

Brick or masonry: Use masonry drill bits and wall plugs rated for the weight of your blind.

Step 4: Mount and Level

Clip the headrail into the brackets as described for inside mount. Check that the blind hangs level by lowering it completely and observing from across the room.

If the blind is not level, you may need to reposition one of the brackets slightly. It's worth getting this right—an unlevel blind will be noticeable every time you look at it.

Final Adjustments and Safety

Adjusting Length

If your blind is too long, most venetian blinds allow for length adjustment:

• Lower the blind completely
• Remove the bottom rail caps (if applicable)
• Slide out excess slats from the bottom
• Cut the ladder tapes to the new length
• Rethread the lift cords through the new bottom slat
• Reassemble the bottom rail

This process varies between manufacturers, so consult your specific blind's instructions.

Installing the Cord Cleat

Australian safety standards require that cord cleats be installed to keep cords out of children's reach:

• Position the cleat at least 1.6 metres from the floor
• Mark and drill screw holes
• Secure the cleat firmly
• Wrap excess cord around the cleat

Testing Operation

Before considering the job complete:

• Raise and lower the blind multiple times to ensure smooth operation
• Tilt the slats fully in both directions to check the tilt mechanism
• Verify the blind stops at your desired positions
• Confirm the cord cleat keeps cords securely wrapped

Troubleshooting Common Issues

Blind doesn't raise evenly: Check that all brackets are level. If one side rises faster than the other, the lift cord may be tangled inside the headrail.

Slats won't tilt: The tilt rod may be disconnected from the tilter mechanism. Remove the headrail from the brackets and check the connection inside.

Blind falls out of brackets: The clips may not be fully engaged. Remove and reinstall, ensuring you hear a click from each bracket.

Blind is too tight in the recess: If an inside mount blind rubs against the frame, you may need to have the blind cut down slightly, or switch to an outside mount.

When to Call a Professional

While most installations are straightforward, consider professional help for:

• Very large or heavy blinds (over 2.4 metres wide)
• Unusual window shapes or angles
• Installation into concrete or difficult substrates
• Motorised blinds requiring electrical connections
• Multiple blinds where time savings outweigh cost

A properly installed blind will operate smoothly and look professionally fitted for years. Take your time, measure twice, and don't hesitate to adjust bracket positions until everything is perfect.