Walkon glass against a wall or facade

We are asked often about the best way to integrate walkon glass or a rooflight into the (roof) terrace or on the roof. Sometimes it is easy, when there is enough room for a raised edge on all sides. Then it is just a matter of implementing as flush as possible into the terrace floor. Yet occasionally the architect will make a drawing of the glass against the façade or a wall and then how to create a solid and watertight constructions? In this article we explain how a wall abutment works and in which cases you should opt for a different solution after all.

What is a wall abutment?

We can supply rooflights and walkon glass with a wall abutment on a maximum of three sides, where the glass is attached directly to the wall, so it does not need to fall across a raised edge. This construction ensures watertight fastening with a Sky Only View from inside. Example project below shows how a multi-piece rooflight is fastened between three walls by use of a so-called ‘wall abutment’.

Other common situations in which a wall abutment is applied:

• A rooflight in an extension of a house: using the wall abutment the rooflight can be fastened directly to the wall, causing a lot of daylight flowing directly into the extension.
• A narrow rooflight as a connection between two buildings.
• A smaller terrace in which every centimetre counts and where there is too little space for raised edges all around.
• A light well that allows light to flow in into the floor below.

Let’s take a look at the details of this construction. In drawing below one can see that where normally a rooflight or walkon glass would fall across four raised edges, in the case of a wall abutment only three raised edges are required, because on one side the glass is directly fastened to the facade/wall by use of the wall abutment.

In order to ensure proper drainage, a slight inclination of 1 degree is required for walkon glass and at least 3 degrees for a common rooflight. That drainage is also the reason that a wall abutment can be applied to no more than three sides: Otherwise the water couldn’t be drained at all.

Example below shows what a wall abutment looks like: the frame contains a larger profile that protrudes at the top and the sides to make it possible to properly fasten it.

When zooming into this, we can see that this extra space is 150 mm on the side and 105 mm at the top. In addition, the contractor will apply lead flashing on top of this 105 mm to guarantee water tightness. These sizes can vary per project between 100-170mm depending on the size of the rooflight, we are happy to calculate what this size is for your product.

After installation the frame is decently covered by use of the interior work, so that only the glass remains visible: the Sky Only View.

When is wall abutment not being used?

A wall abutment is a safe, qualitative solution, but sometimes the required extra space on the sides and op top of the frame, is not available. For example in situation below: here, a rooflight of walkon glass for a glass facade is being applied, where there was no height available to fasten the wall profile.

Alternative solution: walkon glass on four raised edges all around

In this situation it was chosen after all to use four raised edges all around, sunken in the concrete floor, so that the rooflight of walkon glass will be situated flush with the eventual terrace floor. Important condition here, is that the drainage is well taken care of to prevent the gutters from filling with water.

Details of this construction:

By making use of four raised edges, the walkon glass can be applied flush, with this magnificent end result, where wooden parts, tiles and a grid are variedly applied to be able to control the water drainage:

Other example: a light well made of walkon glass with a wall abutment

In this example two rooflights of walkon glass are installed as a light well for this remarkable villa. In this situation height is available, just as space on the sides for the wall profile. With the wall abutment on one of the long sides, the walkon glass can then easily be fastened to the facade. During the finishing of the terrace, the terrace floor will be at the same level with the glass parts again. This causes a great effect from the outside, while inside it ensures a huge amount of daylight and a more pleasant living environment.

Final result of this beautiful villa by Koelewijn Bouw:

The wall abutment can be applied with rooflights and walkon glass, but also when ventilation rooflights or roof access hatches are being used.

Want to know more? Feel free to contact us.