How To Measure, Install and Maintain Venetian Window Blinds

How To Measure, Install and Maintain Venetian Window Blinds

Venetian Blinds – How to measure


There are a number of things you need to consider when measuring for new blinds. Below is a quick guide to help you. Firstly make sure you have a pencil and some paper and a tape measure (preferably a metal one).

What to measure in…

Always measure in millimetres (mm) as most blind suppliers require a size in millimetres.

Where to measure…

In normal window areas there are 2 potential places for your blinds to be installed, these are known as the window face, or the window recess. All Venetian Blinds can be fitted to the face of your window frame or wall, or into the top of the window recess. This gives you complete control over the positioning of your blind.

For a recess measurement:

Make sure you have enough depth to mount the Venetian Blind inside the window frame area. 50mm should be fine; any less will result in the blind protruding out of the recess. If you have less than 50mm it may be worth considering installing your blind outside the window recess as a face fit.

1) Measure the width of the recess from wall to wall at the top. This is where the brackets will be fitted. Be sure to measure across 3 areas of the width to ensure the area is the same width (or very similar) and the walls do not have bulges that will affect the operation of the blind.

2) Note down the shortest measurement.

3) Take off 10mm each side – this will give you some flexibility in case of any variants in your walls and will ensure your blind doesn’t get damaged when operated. If you want to cover the total window area we suggest you fit your blind to the window face.

4) Measure the drop by taking the measurement from the top of the recess to the bottom.

5) Note down the measurement.

For a face measurement:

1) Measure the exact width of where you’d like your blind to be. As a guide, add an overlap from the window frame of between 50mm and 100mm, this will help reduce the gap at the side of the blind, providing better light control and more privacy.

2) Note down the measurement.

3) Measure the drop from the top of where you want your blind positioned to the bottom.

4) Note down the measurement.

And remember…

• Ensure that on all recess width measurements that you have deducted 10mm from each side.

• Measure at least twice to make sure there are no errors.

• Note the side you wish the controls to be so that they are easily accessed.

• To be sure of a great fit it is important that when measuring you account for any obstructions like window handles.

• For full-length windows we recommend that you measure to approx 20mm off the floor. This will give enough clearance and allow the base rail to move freely.

• For face fit installations remember to raise the blind by 250mm above the frame to allow the Venetian Blind mechanism to clear as much glass as possible when raised. This will allow more light into the room and is important when blinds are on doors, to allow for clearance.

Other installation considerations

Shallow sill depth (recess fitting):

Around 50mm minimum sill depth is required to fasten all brackets as the minimum depth necessary for a flush mount (where the product does not protrude into the room). If your sill depth does not cover this you should probably consider a face fit installation.

Corner windows:

When two Venetian Blinds meet in a corner or in a corner where there is only glass, there can be a privacy problem. That’s due to a gap where the products fit together. In order to minimize the problem, consider making one product bypass the other, then specify the other product to fit flush into the first.

It is important to consider the side your controls are on when specifying Venetian Blinds for corner windows. Make sure you do not block the control mechanism with the overlap.

French doors and sliding doors:

Venetian Blinds are not the best solution for installation over French Doors and Sliding Doors. When raised Venetian Blinds leave a stack of slats which fall down between 50 and 250mm depending on the length of the blind. If you want to keep the full door area cleared when the blind is raised then the blind needs to be specified wider and taller. You will need a minimum of 50mm (width) x 250mm (drop) additional space per Venetian Blind for the mounting brackets at the top. This higher and wider measurement means that when the Venetian Blind is raised it blocks less of your view and space to move in and out of the door.

We recommend you consider Roller Blinds for installation over French or Sliding Doors. Roller Blinds have less depth when raised than Venetian Blinds. However this is your choice, by no means does this mean you cannot install Venetian Blinds.

For the width you also should add at least 25mm on both sides of the glass (50mm in total). However door handles may constrain the width you’d prefer. Ideally the Venetian Blind should fall just inside the door handle. All Venetian Blinds can be specified to mount either within the doorframe (RECESS) or over it on the wall (FACE). When deciding this ensure you measure to see if the handle is an obstruction.

Venetian Blinds can be installed on either a wood or metal doors. For metal doors, you’ll need “metal screws” designed for attaching to metal doors.

Venetian Blinds – How to Install


Venetian Blinds are easy to fit and we are confident it won’t take up too much of your time.

Be sure to read all of the instructions below.

You’ll need:

1) Power drill

2) Drill Bit

3) Phillips Screwdriver (The one with the crossed head)

4) Flat head Screwdriver

5) Box of Screws

6) A pencil

How to fix your brackets into…

Concrete, Brick or Plaster:

If you’re drilling into concrete, brick or plaster you should use a 5.0 mm diameter masonry drill bit. You will also require wall plugs and 1 inch phillips head screws (8 gauge).

Wood or Steel:

If you’re drilling into wood or steel you should use a 3mm diameter high-speed steel drill bit. Often in wood you can secure the screws into the wood without any need to pre-drill.


If you’re drilling into tiles then cover your drilling point with masking tape. This will prevent the drill from slipping.

Installation guide for Venetian blinds

1) Gather your tools and unpack your blind.

2) Locate the installation brackets which are supplied as a pair.

• Have a look at your blind and see which side you ordered the control to be on.

• It is very important that the brackets are mounted so that the blind is level when installed.

• Decide where you want the blind to be positioned. The brackets can be placed in 3 different ways:

Inside the frame (recess fit) mounted to the side of the window recess.

Inside the frame (recess fit) mounted to the top (ceiling) of the window recess.

Venetian Blinds can also be fitted outside the window frame (face fit).

3) Mark out your drill holes with a pencil using the blind brackets provided as templates for holes. Ensure that the brackets are perfectly level, so that the blind rolls up and down straight.

4) Drill your holes and then screw the brackets into place.

5) Simply clip the blind into place by sliding the Venetian Blind into the brackets and then close the clip to hold the blind in place.

6) Attach the valance clip and then slide the valance into place.

7) Some Venetian Blinds are supplied with hold down brackets. Simply fix the hold down bracket to the base of the window recess or to the face of the wall outside the window recess. The base bar of the Venetian Blind will clip into the bottom of the brackets.

Shortening the length of an Venetian Blind

8) Hang the blind in a fully open position (full length from top to bottom) then mark the desired length.

9) Remove the bottom rail buttons and using scissors cut of the knots from the lift cords.

10) Pull the lift cord from the bottom rail and slide out the bottom rail and the unwanted blind slats.

11) Replace the bottom rail beneath the bottom slat and cut off the excess braided ladder string. N.B. Be sure you don’t cut off the lift cord.

12) Now re-thread the lift cords through the bottom rail and tie in a knot. Twist the braided ladder string ends together and insert into the bottom rail. Replace the bottom rail buttons.

Venetian Blinds – How to Maintain


Cleaning the blind only requires a damp cloth. Make sure not to rub the blind too hard when cleaning as you may damage the slat by kinking or bending the blind slat.

Removing the blinds

If you would like to take your blind down, simply unclip the brackets and release the whole blind. Make sure you have hold of the blind securely so it does not drop down -ideally have someone to help you do this.

Blind damage

If your blind gets damaged many of the component parts can be replaced inexpensively. Common replacement parts include the bottom rail and chain. The bottom rail might need some more intricate work to replace so we recommend you send it back to your supplier for the rework.

Troubleshooting / Common Problems

The blind slats will not lower

When you initially attempt to lower the slats the cord lock may not release causing the slats to not lower. Firstly hold the lift cords level with the headrail and pull. This should release the cord lock. If this does not fix the problem, take the blind out of the window. Locate the cord lock mechanism in the headrail where the cords run through. You will see a pin that should slide out and release the cords; in this instance it will be tight to the cords restricting their movement. Using a flat heads screwdriver carefully push the pin to disengage the cords ensuring you don’t touch the cords and damage them. When the pin releases the slats will lower so be sure that nothing is in the way when the slats release and people are clear of the area as they may be injured.

The blind hands unevenly

Raise the blind and then extend the blind completely. Repeat this operation slowly several times until blind hangs correctly. You can also manually adjust the way the blind sits, however be careful not to damage the blind when doing so.

Need to replace slats

Remove the ladder cap from the underside of the bottom rail. This will expose the ends of the cords, which you can then pull out slightly. Cut the cord just above the knot and then pull the cord up through the last damaged slat. Remove the slats and replace them with the new ones, making sure that you insert the slats so that the route holes are aligned with the existing slats. Then weave the cords through the route holes being certain to alternate the sides of the ladder rungs as you proceed down the blind. Reinsert the cords into the bottom rail and tie them off. Replace caps.

We hope this guide tells you everything you will need to know to successfully measure, install and maintain your Venetian Blinds