The choice of roof sheet is often made last, while it is precisely the decision that shapes daily use the most. Light, sound in the rain, temperature in summer and how often you have to clean the roof: it all hangs on it.
Polycarbonate
Polycarbonate is light, relatively cheap and does not break. The hollow chambers in the sheet make it insulate better than single glass. The downside: it is less clear than glass, it yellows a little over time, and rain is clearly audible. For a canopy that mainly has to offer protection from sun and showers it is a fine choice.
Clear glass
Glass gives the most light and the calmest view: you look through the roof as if nothing were there. It is heavier, so the structure has to be calculated for it, and it costs more. Rain is barely audible. A glass veranda does heat up faster in summer, so sun protection is usually no luxury then.
Laminated safety glass is the standard here. Should it ever break, the shards stay stuck to the film instead of coming down.
Sandwich panels
A sandwich panel is a solid, insulated sheet: two metal outer layers with insulation in between. It turns the veranda more into an outdoor room than a canopy. It stays cooler in summer and warmer in spring, and you barely hear the rain.
De afweging is licht: een dicht dak laat geen daglicht door. In de praktijk wordt daarom vaak gecombineerd — een dicht deel boven de zithoek en een lichtdoorlatend deel daarnaast, of lichtstraten in het paneel.
How do you choose?
Ask yourself three questions. How much daylight do you want to keep in the room behind the veranda — a solid roof makes the living room noticeably darker. Will you use the space in spring and autumn too, or only in summer? And how much do you mind the sound of rain?
If you are unsure, it is worth seeing the sheets side by side. In the showroom they lie there at full size, and that works better than any description.