Conservatory roofs

3 Facet Victorian Roof

There is a lot of confusion relating to polycarbonate and glass roofs, for that reason we have tried to give an unbiased opinion of the two to try and help you make the right decision when purchasing your conservatory.

Initially the roof structure remains to a large extent the same for either polycarbonate or glass.

Structural aluminium rafters and tie bars form the skeleton of the roof these rafters may be bolstered (made deeper) to avoid any deflection (bending) to accept the heaver weight of glass plus rain and wind loads.

Polycarbonate roof:
Polycarbonate roofing sheets are manufactured in various thicknesses and 3 colours. For the purpose of this chapter we have only referred to the more commonly used.

As always there are varying factors.

• With the 10 mm and 16 mm you will hear the rain, I have found that some people like to hear the rain others do not, and it’s a matter of choice;



• 25 mm you will only hear the rain during a heavy rain storm;



• As polycarbonate is always opaque when you look up at the roof you will not see the bird’s poo or dirt from the inside and that’s a big plus.

10 mm twin wall polycarbonate. This specification is very basic whilst cheap, because of it's thickness it is very noisy when raining, and has poor insulation properties.

• 10 mm Clear twin wall polycarbonate Light transmission approximately 80%. U-factor approximately 3.1
• 10 mm Bronze twin wall polycarbonate Light transmission approximately 45%. U-factor approximately 3.1.
• 10 mm Opal twin wall polycarbonate Light transmission approximately 40%. U-factor approximately 3.1.

16 mm, triple wall polycarbonate. This specification is middle of the road whilst cost effective, because of it thickness you will still hear the rain, and has medium insulation properties.

• 16 mm clear twin wall polycarbonate Light transmission approximately 80%. U-factor approximately 2.4.
• 16 mm Bronze twin wall polycarbonate Light transmission approximately 50%. U-factor approximately 2.4.
• 16 mm Opal twin wall polycarbonate Light transmission approximately 45%. U-factor approximately 2.4.

The lower the u-factor the higher the insulation.

25 mm, five wall polycarbonate This specification is one of the best on the market at present and is cost efficient, because of it thickness you will only hear heavy rain, and has good insulation properties,

• 25 mm clear five wall polycarbonate Light transmission approximately 75%. U-factor approximately 2.4
• 25 mm Bronze five wall polycarbonate Light transmission approximately 45%. U-factor approximately 2.4
• 25 mm Opal five wall polycarbonate Light transmission approximately 40%. U-factor approximately 2.4

60 mm twin wall polycarbonate This polycarbonate is very strong and normally used with a low pitched lean-to-roofs of around 2.5 degs, and is light blue in colour, it's specification is one of the best on the market and is cost efficient, because of it thickness you will only hear heavy rain, and has excellent insulation properties with a U-value of 1.9.

The lower the u-factor the higher the insulation.

The 3 colours manufactured are suitable for use in the following conditions:

Opal Polycarbonate Sheet Opal: Its properties are very good for protection from the sun and are ideal for conservatories facing south or south west. It also has another benefit in being opal this make your conservatory light even on cloudy days and will also reflect the light back into your conservatory at night from your lights, clear polycarbonate and bronze will allow light to filter through into the night sky.
Bronze Polycarbonate Sheet Bronze: Its properties are very good for protection from the sun and are ideal for conservatories that are facing south or south west. But its worth remembering that it may make your conservatory a tad dark on overcast or cloudy days if used on north facing sites. However it looks good with uPVC mahogany and hardwood conservatories.
Clear Polycarbonate Sheet Clear: The name is a bit misleading as it is not clear like glass but slightly obscure, and is probably the most used of polycarbonates. If it is used in south or south west positions you may find that the conservatory is very bright and you may need roof blinds also the solar gain will increase making the conservatory warmer.

Glass Roofs

A glass roof is properly the highest specification for your conservatory, and considerable advances have taken place over the last few years as you will now observe

The glazed sections of the roof are made up in what is called sealed units and are exactly the same as the double glazed units in the windows of your house or conservatory, normally these are 25 mm in thickness and can be filled with argon gas to increase the thermal insulation and have a special invisible coating to reflect the heat away from your conservatory some times known as Pilkington solar glass therefore keeping it cool, and for any of you who just hate cleaning windows wait for it. Self cleaning glass, impressed!

Conservatory glass roofs

The sealed glass units are much heavier than the polycarbonate sheets mentioned above. Therefore the glazing bars may have to be deeper to avoid any deflection of the bars.

Around 15 years ago when glass was first used for conservatory roofs there a few teething problems.
These were.

• Conservatories got very hot during the summer and chilly during the winter
• Due to the transparent glass roofs, conservatories were found to be very bright to the eyes on sunny or light cloudy days
• The roofs were not easy to get to so they often stayed grubby unless you had a friendly window cleaner.

With to day's next generation of glass we have now overcome all of these problems.

Conservatory too hot?

The reason conservatories get hot and uncomfortable during the summer is mainly from solar gain, even a bright cloudy day will warm up your conservatory, also it can damage and fade your soft furnishings but with solar reflection glass you will not experience this as it reflects up to 75% of solar heat from conservatories.

Conservatory too Cold?

Conservatories can also be cold if the insulation is inadequate making your conservatory uninviting during the winter months. But imagine looking at the frost and snow on the trees in your garden from a warm cosy conservatory you will think you have been transported to Nania the only thing we can't provide is the lion and wardrobe. All of this is possible with high insulation argon gas filled sealed units plus low E glass which reflects heat back into your conservatory and gives you with a U factor of 1.1 remember the lower the U factor the higher the insulation.

Conservatory too bright?

Brightness can be a problem in conservatories there is nothing worse then sitting in a conservatory when the sun is out or even on a bright cloudy day you find that you are constantly turning away from the light or reaching for your sun glasses. With Cervoglass it's possible to reduce light transmission by up to 53%, so you can sit comfortably without squinting to read the Sunday papers.

Window Cleaning

One of the nice things about a glass roof is that you can look up and see the canopy of trees, the sky, moon and stars at night but regrettably, also the birds poo and dirt until now, for all of you who just hate cleaning windows there's self cleaning glass, it's not the best of jobs trying to climb onto the conservatory roof to wash off the bird's poo or dirt. So now we have Bio glass a special coating is applied to the glass which uses daylight and rainwater to wash away organic dirt from the roof making it ideal for roofs of conservatories produced by the very cleaver people from Pilkington glass. This wasn't about in George Formby's days either.

4 features in 1 glass roof

As you have read glass roofs have many features, you can have one or all four of these options.
You have as many choices of extras in a conservatory today as you have when buying a new car.

Please note these statistics have been taken from Cervoglass of Liverpool who have allowed us to print this data.