Velux Windows in Archway

A Velux window is a brand of roof window, but the brand is so popular that people often use the name to describe the entire type of window. They are windows that are installed at the same orientation and ‘in plane’ with the surrounding roof, and they’re usually installed at a minimum of a 15-degree pitch. You can buy roof windows that offer completely frameless internal views for a really clean look in your loft conversion, while some come with built-in shutters.

Velux windows aren’t to be confused with rooflights which usually refers to a glazed unit that’s installed on a flat roof. It might also mean a window that’s been installed on a pitched roof out of plane with the level of the tiling.

People also confuse roof windows with skylights, which normally can’t be opened or closed and are usually smaller than Velux windows. Skylights, therefore, only let daylight into the room whereas roof windows also help with ventilation.

If you’re using your loft as a room in your home rather than simply for storage, you must have a roof window installed. Skylights won’t be enough as they don’t allow for ventilation. It doesn’t have to be a Velux window – it can be any type of roof window. Luckily, they tend to come in standard sizes and they must be CE marked if they’re sold as a roof window, so they should be easy to find.

Velux windows are a great way to add lots of light to your loft space. Velux is actually the name of a brand of roof window – not to be confused with roof lights, which are usually installed on flat roofs, or skylights, which are normally used to add natural light into a room without being able to open it. Roof windows open like regular windows and are fitted within your roof. But how much are Velux windows? Whether you choose a Velux window or another brand of roof window, they’re not cheap. Since they require special installation, including cutting roof timbers and replacing them to keep the structure strong enough, they take longer to install than a normal double glazed window. It can take up to a day to install a large Velux window, and it could set you back anywhere between £1,600 and £2,000. If you only need a small roof window in an area like a bathroom, you can expect to pay up to £1,300 for it to be fitted. Usually, there won’t be any need for scaffolding or towers because Velux windows are designed to be installed from the inside of your home. However, it’s worth setting aside an additional £500 in your budget in case unexpected problems occur and an installer needs to get on your roof to finish fitting the window. All of these prices are based on a standard roof window without any additional features. If you want to be able to control your windows with an electric switch or remote, this could set you back as much as an additional £400. For extra-low energy glass, you can expect to pay up to £200 more.

Velux windows, or roof windows, are very easy to clean. Regular cleaning helps to keep them looking bright and shiny for years to come. So how should you clean Velux windows?

If you want to clean the air filter, you can remove it and wash it with your normal household cleaners. Velux windows have a cleaning position, so rotate and secure it into this position then remove the filter. You should be able to buy new filters from the manufacturer of your roof window.

To clean the outer pane, there’s no need to lean out of the window and risk falling out. Simply rotate the sash (the opening part) 180 degrees and secure it into position. Then you can clean the pane with a soft, lint-free cloth, sponge or squeegee and clean water. If you live in a hard water area, add some detergent to the water and wipe the window dry when you’re finished. You can also use normal non-abrasive household cleaners.

It’s recommended that you clean the flashing around your roof window at least once a year. You can use a brush to do this. This will allow rainwater to flow freely and stop any leaves from collecting.

If you’re in any doubt about using certain cleaners on your Velux windows, get in touch with the manufacturer who should be able to help. You can also do a patch test on an inconspicuous area if you’re unsure.

Fitting a Velux window into a slate roof is very similar to the way you’d install it in other roof types. All roof windows, whether a Velux-branded one or not, will come with detailed instructions for you to follow if you want to have a go at fitting it yourself. But here are some brief instructions to give you an idea of what’s involved in installing a Velux window into a slate roof:

1. After you’ve removed the Velux window from its packaging, remove the sash (the part that opens) from the frame, according to the manufacturer’s instructions.
2. Next, you need to prepare the opening for the window. You can often cut through the felt, remove one of the battens from under a slate, then slide all the slate tiles into the roof space. You should then make the cut 40-60mm wider than the window, cutting away roof timbers then replacing them with more around the opening to strengthen it.
3. The roof window’s bottom brackets need to be installed on one of the existing battens for the slate roof. One of the slate courses should line up 105mm below the top edge of the batten you use.
4. Then, measure from the top edge of the batten upwards to the height of the window plus 45mm. This is where the top installation batten should be installed, with an overhang of 100mm on each side.
5. Remove the course of slates below the window, trim any excess felt and fold it over the surrounding timber. This helps with waterproofing.
6. Add the insulation collar according to the Velux window manufacturer’s instructions.
7. Place the frame in the opening, adding the brackets according to the instructions. You’ll find that lots of roof windows have pre-drilled holes to make it easy for you.
8. Replace the sash and line up the hinges. Take a look at the opening at the bottom between the sash and the frame – it should be even along the entire width. Remove the sash again to fix the upper brackets according to instructions.
9. Add the underfelt collar for your roof window as instructed by the manufacturer, then replace any slates at the bottom. You might need to cut them to size.
10. Next, add the flashing according to the instructions, along with any parts that are not yet attached, including the hood section and top flashing piece.
11. Replace all the slates around the window, allowing 60-100mm of space between the course of slates above the window and the top of the window to allow for rainwater drainage. Then replace the sash into the frame again.
12. Add the vapour barrier on the inside of the window using the screws provided, then tape it to the existing vapour barrier to prevent moisture from reaching your roof structure.

And that’s it! If you think that sounds a bit complicated, ask a roofer or window installer to fit your roof window into a slate roof for you. You’ll get a better finish and you can be sure that you won’t get any leaks from a botched installation.