Walkon glass laid flush with the roof terrace floor

Walkon glass is preferably applied as flush as possible with the floor. But how is that done, while also monitoring the water tightness? This article shows all do’s and don’ts.

Watertight installation of walkon glass

In order to install walkon glass watertight, two aspects are important:

Water should not be on the glass for a long time

Leakages arise when water remains on the glass for a longer period of time. There may be a leak in the glass, water may seep between the glass and the frame, or the glass has been placed in a sort of ‘bowl’ due to which it cannot run off the glass.

Solution: suppliers such as Glazing Vision supply walkon glass that is laid ‘Flush’ with the aluminium frame and sealed by use of a silicone joint. In addition to ensuring water tightness, this also ensures that a thermal bridge is prevented as a result of the thermal interruption of the system.
Result: no loss of warmth. – Water cannot soak on the sides between the glass sheets as it does with traditional systems. – It is a ready-to-use product, so that no architectural provision needs to be put in place.

Water should not accumulate on the roof

In addition to rain water falling from the sky, periods of heavy rainfall may cause water to remain on the roof. Of course it is imperative to have the water management on the roof in order. Roofs are already installed at a minor slope and the drainage of water via the gutter must be properly organised.

Solution: by placing the walkon glass on a raised edge, at sufficient height, you ensure that no leakage arises as a result of water remaining on the roof.

Result: with a raised edge of 150 mm high, the glass is watertight. Applying the rest of the terrace at equal height creates a nice and flat connection. This can be done by use of tile supports, drainage channels or other support and raising systems that protect the flood defence layer of the roof. A small 6 mm gutter between terrace and glass is required to drain the water.

But what if I can’t get to 150 mm height?

Sometimes it is necessary to place walkon glass on a lower raised edge, for instance, to make the creation of a step possible. Or it is not possible to get a roof terrace floor to a height of 150 mm. You don’t want the walkon glass to be ‘on’ the floor. So what can be done?

Solution: it is possible to lower the raised edge lager and still keep it watertight. With a special EPDM-profile that is attached to the frame you prevent that rising water, in case of sudden torrential rain, may cause leakage via the bottom side. This profile covers the connections, is adhered to the roof covering.

Result: the EPDM-profile (marked in yellow in drawing below) ensures that the raised edge does need to be 150 mm, but only 80 mm high.

EPDM-profile lowers the minimum height of the raised edge from 15 mm to 80mm.

Example: light in a dark patio

At the Lampenistenstraat in Amsterdam and many surrounding streets, the houses have a sunken patio, where the sun rarely shines. The architect therefore wanted to include the patio to the house, but not lose the light. Moreover, the architect wanted to extend the roof terrace floor, so that all space could be used. Thus in the roof terrace a more than 5 m2 walkon glass floor was installed.

Example: walkon glass in a green roof

Green roofs are becoming increasingly more popular, mainly in urban areas. Obvious, because not only do they look pretty, they also provide additional water storage, they purify the air and keep the house cooler in the summer and warmer during the winter. The higher moisture content in the vegetation layer of the roof makes the water tightness additionally important. Walkon glass is easy to apply on green roofs by use of the EPDM-profile. That is great, as such you combine the natural green on the roof with the light in your home.