What is a Skylight upstand?

Adding a skylight to a flat roof can bring in natural light and air to the room below and even work on allowing correct ventilation.  The addition of an upstand is an important factor for both building regulations and also to make the skylight work correctly.  But what is an upstand?


Skylight basics

Also commonly known as a kerb, there are four main types of skylight that are currently used around the UK.  These are fixed, opening, eco and walk-on.  Each has benefits depending on what you want from the window.

Fixed skylights are just that – they don’t open so are fine for rooms where ventilation is already being provided somewhere and the skylight is purely to add some light to the room.

Opening skylights come in a number of designs and allow air to circulate in the room below as well as letting in light.  Some of them can be opened electrically via a switch and even one system may operate two windows at once.  Advances on this include rain sensors that shut the windows automatically when it begins to rain and temperature settings.

Eco skylights are aimed at increasing the energy efficiency of a house and are more effective at this than the other options.  They normally use triple glazing and contain Krypton gas meaning they have the lowest U-Value of any style.  They allow sunlight to radiate through the house with its positive benefits and reduces the need for artificial light at the same time.

Walk on skylights are especially designed for areas where they will have people walking over them such as for a roof garden area or a balcony.  They are made from strengthened inner and outer glazing.

A large up stand installed onto a GRP flat roof

Why do I need an upstand?

An upstand is the fixture that keeps the glazed unit from coming into contact with the surface of the roof and is needed for most building regulations. Upstands need to protrude by a minimum of 150mm above the roof and have a pitch of a minimum of three degrees.  This allows water to run off the window and also means that in the future, should the window need repair or replacement, the roof itself does not need to be touched.

It is common for and upstand to be constructed at an angle for a pitched roof window to be installed in a flat roof. This means creating a false 15° (or more) angle by sloping one side of the opening to the other. These forms also often come pre fabricated by many manufacturers such as Velux and Fakro, but that is not to say that they cannot be constructed from timber.

One of the most popular material for an upstand is timber, because it is sturdy and strong as well as having insulating qualities.  This also means that they can potentially be made at home, as long as you have a basic wood working ability.

Some brands of skylight have a complementing range of upstands available that are designed to work specifically with them.  If you are less than confident about making your own upstand, then this may be worth considering.  The other advantage with this type of upstand is that the flashings from the window will work perfectly with it, as they are all made together.  As long as you know the basic dimensions of your skylight, it is also possible to buy one of these upstand to use with your window.


Have a look at our range of upstands here

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