Roof – Glass or Polycarbonate

Glass Polycarbonate
Light Transmission Gives a clear view of sky, trees and stars Opaque transmits only 80% of the light transmitted by glass when new, deteriorating to 70% over 10 years – a difference which will be noticeable in low light conditions such as evenings or winter days.Bronze tinted polycarbonate is available, but this will darken the conservatory and adjoining room considerably, and will not have any cooling effect – blinds will still be required in most south facing conservatories.
Does not deteriorateSurface can be cleaned much more easilyDecorative patterns and solar reflective panels available. Surface is soft and easily scratched by birds, fine grit in strong winds etc.Green algae and mold can form outside and within units.Stains easily, and cannot be cleaned using certain cleaning agents
Sealed double-glazed units.Low E Coating can be offered. Units cannot be sealed and therefore cannot provide the same heat and noise insulation as glass double glazing.
Double glazed units reduce the amount of outside noise getting into the building and escaping from within. Reduced noise insulation (see above)Very noisy when it rainsCan emit loud bangs or cracks with expansion or contraction during temperature changes.
Withstands storms and heavy snowfalls better because it is stronger.Could shatter if struck by a sharp object – NB. will shatter into many small pieces NOT long shards. Easily cut or prised off by burglars.Can be torn out in high windsCheck insurance policies carefully – may not cover damage to polycarbonate roof sheets from fireworks, bonfire sparks etc.Very dangerous to stand on.
More expensive to install and replace.If fitted to a poorly constructed conservatory, a glass roof will increase costs considerably, as the conservatory will not have the strength to support the additional weight.However, if fitted to an architectural aluminium conservatory, which will be some 25 times stronger than a upvc equivalent, the additional cost will be low. Cheaper.There are many different qualities of polycarbonate – it may not be easy to know the quality you are fitting without expert independent advice.
Very heavy to liftConservatory must be much more substantial to withstand weight. Lighter, easier to fitCan be fitted to cheaper, more lightweight conservatories.
Enduring quality appearance over many years.Sealed units can breakdown if not manufacturerd to a high standard (should be to BS 1279/2) Limited lifespan – deteriorates under normal weather conditions.Ultra-violet degradation can occur, leading to possible penetration by hailstones.Some manufacturers offer only 5 years guarantee, or no guarantee against hailstone is some cases.