Many builders offer to install VELUX windows, but many probably shouldn’t. We’ve replaced and repaired hundreds of VELUX windows, and the chief reason is because the windows were initially badly installed.

Experiencing VELUX problems

There’s rarely a problem with VELUX themselves. There’s a good reason why VELUX are effectively synonymous with roof and skylight windows. VELUX are simply the highest quality products available. Their windows are fantastic, and with good installation will last a decade or more. We have so much faith in them that we offer a 10 year guarantee on all of our VELUX installations.

However, things can go wrong. Issues crop with VELUX skylight installations because of 2 main reasons. Firstly, age – they won’t last forever. If you’re seeing problems with your VELUX and you’ve had them for upwards of 10 years, it can be worth looking at calling someone in for minor repairs and, for more problematic cases, even getting a replacement.

The second major reason is bad installations. If problems start cropping for your VELUX installations and it’s only been anywhere between a few weeks and a few years, your installation is faulty. Here’s what to do if your VELUX has been badly installed.

A badly installed VELUX window that has cracked and is leaking
Getting a poorly installed VELUX fixed is imperative. Over the time the problem will worsen, as it can lead to leaks and damp ingress, and the window can even break due to the structural issues with its installation.

Let’s take a look at your builder

There’s no point in crying over spilt milk, even if it’s leaking through your VELUX. We’re not asking you to check your builder is reputable to make you feel regretful about your choice of installer – it’s still relevant information now to get a gauge on whether the builder would have done a quality job and whether they offer any warranty.

We can’t stress enough: when getting VELUX installed, choose a VELUX Certified Installer. These are people who’ve been accredited and approved by VELUX themselves. There’s no higher sign of trust and mark of quality when it comes to skylight installations.

VELUX Certified Installer badge for Brighton & Hove
Look for this stamp. A VELUX Certified Installer is guaranteed to do a good job, and carry a 10 year warranty on their work.

Take a look through your builder’s website and any documents, brochures, or promotional materials you still have from them.

If there’s a VELUX Certified Installer stamp

This is great news! If your builder is a VELUX Certified Installer, they have to provide a 10 year guarantee on their work. That means, they have to come and back fix up the job to make sure it’s all hunky dory. Problem solved.

If there’s not a VELUX Certified Installer stamp

Uh oh. Without VELUX Certified Installer status, there’s little guarantee that the installation was performed to correct standards, and could have been badly installed. There’s also no requirement of the company to offer a guarantee or warranty on the installation. Many builders who aren’t within the VELUX Certified Installer scheme choose to have very short expiry dates their work guarantees (e.g. 1-2 years).

Signs of a bad installation

Outside of looking at your builder, the next clues come from the window itself. The most common signs that your windows have been badly installed are…

Leaks and water ingress around the window

Often not an issue with the window itself, but what’s called the ‘flashings’. Flashing kits are used with VELUX windows for 2 main purposes. Firstly, from an aesthetics standpoint, they ensure the window seamlessly integrates with your roof, be it slate, tile, or other material.

Secondly, and more importantly, they act as weather-resistance. They ensure that rainwater, even in heavy storms, is directed around and away from the window, and provide a barrier and sealant between the window and the roof. Think of them as a bit like your window’s very own mini-gutter.

A man fitting a new VELUX frame where leaks caused damage
Here we fitted a new VELUX frame, as a bad installation meant that leaks and water ingress were occurring around the VELUX window.

The flashing also includes some ‘aprons’ towards the top and bottom of the window, which further seal out water and prevent penetration.

All too often, flashings and aprons are installed lazily. It’s not noticeable until it’s too late, and water is entering your home.

Feel of the window when opening and closing

A VELUX window should feel smooth when opening and closing. Whether it’s top-hung or centre-pivot, opening and closing should feel like the window is ‘gliding’ through the movement. It shouldn’t feel like you’re having to use excessive force or that the movement is clunky at any point.

On top-hung windows, there’s also a small set of springs instead into the window brackets to help it open. When the springs are engaged, you shouldn’t have to push hard against the window to get it to open, and it should stay open of its own accord. If there are issues when opening and closing, this might be because the window was badly installed.

Window is not square in frame

Another extremely common symptom of a bad installation is the window not sitting ‘square’ within the frame.

When VELUX windows are installed, the frame is installed first, providing a space in the roof. The window is effectively slotted into this space. Often, once the window is installed, small corrections are made to the frame to ensure everything aligns neatly. When you open the window, you’ll see equidistant space between the frame and the window around all edges.

Badly installed VELUX window showing space around the edges

Bad builders often don’t bother with these small corrections, meaning you might notice a larger gap on one side compared to the other. Similarly, upon opening the window, you might see that one side opens further than the other.

You’ll also notice this when opening and closing a window. The window will be particularly stiff or challenging to close around certain areas, where it’s not sitting neatly within its frame. If you have any interior beading and decoration, it may also begin peeling off.

Poorly installed VELUX window with gap at the bottom and difficult to close

Time to repair or replace

If you’re experiencing issues such as the above, or any other, and your VELUX are relatively new then it’s likely they’ve been installed poorly.

Unique Build are VELUX Certified Installers, meaning VELUX themselves trust us to carry out work on their behalf, and you get a 10 year guarantee on work completed by us.

Get in contact and we’ll head over to take a look. From there we can make recommendations about whether it’s best to repair or replace your VELUX.