Can pitched roof windows be used on a flat roof?

Pitched roof windows are a clever way to add natural light to a room. While they can be easily installed on a pitched roof, the question is can pitched roof windows be used on a flat roof? In this article, we show that the answer is yes! There are systems that enable the installation of pitched roof windows even on a flat roof.

Understanding the difference between a pitched roof and a flat roof is essential in the process of choosing the right types of windows. A pitched roof is a roof that slopes downwards, typically with a slope of more than 15°. A roof with a slope less than 15° is usually considered a flat roof. Pitched roof windows are not designed for a flat roof, but there exist systems that make it possible to install windows on flat roofs.

What is the minimum roof pitch for a roof window?

The roof windows can be installed on virtually all types of roofs, be it a flat roof or a pitched roof. That said, roof windows should be chosen carefully as there are many important considerations in relation to roof pitch and roof windows.

Firstly, the deflection should be considered. All glazing has a level of flex that is particularly visible in the overhead installations. The deflection is determined not only by glazing but also by snow loads or wind loads.

Secondly, capping should be considered. With a pitched roof window, it is usually not a problem because the systems for the installation of such windows allow covering the elements by the roof materials. However, if the roof window is installed on a flat roof without the use of a system elevating a window to a pitch of at least 15°, it is wise to choose windows without external capping that can trap moisture and dirt.

Finally, it is important to consider the direction. It is obviously not always possible to manipulate with direction, but if possible, the roof window should face east as you will get warmth and light in the morning. The south and west direction will give you afternoon benefits, but the downside is that the living or working space may be prone to overheating.

Flat roof windows - How do the systems for installing them work?

The basic idea behind most of the systems available on the market is simple – the goal is to elevate the installation angle of the window by around 15° in relation to the roof pitch. This way even a completely flat roof with a slope of 0° partially becomes a pitched roof with a slope of 15°.

Usually, the systems comprise several elements. The existing systems available on the market are made up of solid materials in the form of wooden housing with insulation material and flashing to join the roof window to the housing. The installation of such a system is straightforward – firstly, the wooden housing should be installed and then sealed and fixed to the roof covering. Depending on the roof covering, the methods for that can differ.

Can pitched roof windows be used on a flat roof?

Benefits of flat roof windows.

The main goal of the installation of pitched roof windows is to provide more natural light into the living or working spaces. They are used by many companies as well as individuals because of good thermo-insulating properties that allow saving money on heating and cooling. Such roof windows are also a good esthetic way of adapting the attic to living space.

The systems for installing pitched roof windows on a flat roof can be manufactured in such a way that allows installing horizontal combinations of many roof windows as well as single windows.

Choosing pitched roof windows for a flat roof in living spaces

When the system for installing pitched roof windows on a flat roof is ready, it is time to decide what kind of windows should be installed. The systems usually enable the installation of all types of roof windows.

When choosing windows for a living room, it is usually important to bear in mind the design and finish of the windows. One of the most popular options nowadays is to choose roof windows with a minimalist look such as the flat roof windows with a painted white finish. Such a choice would be particularly suitable if the surrounding walls are painted white. More cozy options include roof windows in traditional wood finishes like oak or pine.

The choice of roof window for a kitchen and a bathroom is more complicated as in these spaces the humidity can be an issue. It is important to choose a type of pitched roof window that allows good ventilation and is moisture-resistant. The systems allowing for the installation of pitched roof windows on flat roofs are also suitable for such windows.

Finally, the roof windows installed in bedrooms should have an extra noise reduction. It is particularly important if you live close to an airport or a busy road. This type of roof window also minimizes the sound of the rain, so it definitely adds a little bit of extra comfort. It is also important to bear in mind that some types of roof windows can prevent overheating in the summer.

There is also one practical aspect to consider when choosing flat roof windows – whether the price includes VAT or is ex VAT. The sellers usually inform about the prices ex VAT, so some customers might be surprised at the time of payment.

Can pitched roof windows be used on a flat roof?

What are the alternative types of windows for a flat roof?

Not only pitched roof windows can be installed on flat roofing. One of the most popular options is glass-domed roof windows. This option is usually used in shopping centers and public spaces. These roof windows are made of polycarbonate and are either single, double, or triple glazed. The downside of these skylights is that the water will condensate if a window is installed in a heated area. This happens due to the difference in temperature on both sides of the window. The triple skin polycarbonate prevents condensation to some extent, but still, it does not guarantee its elimination.

Another option for a flat roof is a roof lantern – it consists of glazing pieces separated by aluminum trims that meet in the middle. The biggest advantage of this type of window is that it visually enlarges the space below as it gives an impression of a higher ceiling.

Finally, it is worth mentioning that the pitched roof windows have one crucial advantage over other types of roof windows that can be installed on a flat roof: they can prevent overheating to a larger extent. Due to their slope, they are not always directly exposed to the sun. They are also easier to open and more exposed to a refreshing wind in the summer than the dome-shaped or lantern-shaped roof windows.

You may be interested also in: Choosing the roof window

Flat roof windows - Wrapping up

A flat roof does not make it impossible to install pitched roof windows. There exist systems that elevate the adequate part of a roof and enable the safe and efficient installation of pitched roof windows. As the installation of pitched roof windows does not change the volume of the roof, it is not necessary to apply for planning permission to install these windows. It is easy to install pitched roof windows on a flat roof and enjoy its numerous esthetic and practical benefits.