Roof glazing: what are my choices and what should I search for?

What is roof glazing? This is an important question which leads to lots of others.

What type of roof do you have and what type of roof glazing do you need to specify or to buy? Please remember not every roof is capable of using, or compatible with, all types of roof glazing.

The following questions should help you through the process of deciding what roof glazing is suitable for your own purpose.

Type of roof

Do you require a product for a traditional pitched roof (tile or slate), a traditional flat roof (bituminous membranes, GRP or single-ply applications) or is it a commercial roof (standing seam or metal roofs)? Perhaps you require a totally glazed roof (mono-pitch, duo-pitch, bespoke shaped, conservatory or an atrium). Are you considering a green or ‘upside-down’ roof? Is your chosen waterproofing lead, zinc, copper or similar?

What is the pitch of your roof? How will the water run off the roof and will this work with the products you wish to purchase or install.


Do you want glass, polycarbonate or GRP? All these are fit for purpose but each has its own good and bad characteristics. What about the clarity of glass versus the strength of polycarbonate versus the economics of GRP.

Roof glazing security

Do you need to consider security issues with an obscure/diffused roof glazing product? Is the roof glazing accessible to vandals, do you need integral burglar bars or extra security fixings or features.

Insulation & Solar Gain

Do you need to achieve a thermal value – Wm2K? Does your property come under Part L1 or Part L2 of the building regulations? Are you replacing like for like or upgrading to new roof glazing? Is this a refurbishment or a new build project?

Do you need to think about solar gain and will you require a tinted option? Will the sun shine through the roof glazing and discolour the internal furniture and decoration?

Rooflight style

Do you want a modular, off-the-shelf, style rooflight; a tubular, tunnel type, skylight; or perhaps a larger area system that will include glazing bars? Perhaps you are looking for a totally individual bespoke option or something that is contemporary with a slimline look.

What aesthetic look do you require? Do you want something that is flat (either in or out of plane), dome shaped, pyramid shaped, ridge light or something more architectural?

What size roof glazing do you need? Is there a minimum or maximum? What is a good rule of thumb?

Roof glazing support

Do you purchase a ready-made upstand or if not how do you perform an upstand to support the roof glazing?

Access and ventilation

Do you need ventilation trickle vents, manual or electrical ventilation? Would you like a remote control roof glazing system, perhaps rain sensors and thermostatic control options? What about condensation and can you expect it to form or even design it away.

Do you need to consider an automatic opening smoke ventilation (AOV) for fire regulations or perhaps a roof access hatch for maintenance and leisure activities on the roof itself. These too can be used in combination with roof glazing.

Does the roof glazing need to achieve a particular type of fire rating?