Roof glazing and rooflights

Overhead glass has to stay up when it breaks

Anything glazed above head height uses a laminated inner leaf without exception. If a toughened pane overhead fails, it disintegrates and falls into the space below — which in an atrium or a reception is an unacceptable outcome.

Laminated glass cracks and stays bonded to its interlayer, held in the opening long enough to close the area and replace it. Where toughened is used in the build-up, it is heat soaked to reduce the chance of a spontaneous failure in the first place.

Pitch, drainage and the reason rooflights leak

Glass needs fall to shed water and to keep itself clean. Below about 5° water sits, dirt accumulates in the low corners, and the seals stay wet — which is where almost every long-term rooflight leak begins.

We design to a minimum 5° wherever the roof build-up allows it, with a drained and ventilated glazing rebate so any water that does get past the outer seal is carried back out rather than accumulating against the unit edge.

Solar gain is the problem nobody prices for

A clear rooflight over an open-plan floor can add several degrees to the space in summer and produce glare that makes screens unusable. It is a bigger practical issue than the heat lost in winter.

Solar control coatings, body-tinted interlayers and fritted patterns are all specified at design stage and cost very little compared with retrofitting shading or extra cooling capacity afterwards.