The different types of Polycarbonate Sheet

Where polycarbonate is used as a roof sheet it is nearly always “multiwall” (the only major exception to this is where solid polycarbonate sheets are used for Overdoor canopies). Multiwall sheets are extruded to produce a number of internal walls which create chambers within the sheet. The number of chambers differs depending upon which sheet thickness you are using.

4mm, 6mm and 10mm thick polycarbonate sheets normally have just two walls and are refered to as twinwall

16mm polycarbonate sheets have three walls, creating two chambers and are known as triple wall

25mm Polycarbonate comes in a variety of designs but the most popular has an “X” type structure with 7 internal walls and is simply called multiwall

32mm and 35mm Polycarbonate sheets tend to have 7 horizontal walls and again are known as multiwall sheets

What thickness of sheets should be used for which projects?

Replacement Glazing

4mm, and 6mm Polycarbonate sheets tend to be used for small scale glazing jobs such as replacing broken glass in Greenhouses or for providing an insulated cover for Koi fish ponds. It is light easy to handle and can be cut to size using a sharp knife.

Carports or Lean to Roofs

Polycarbonate is commonly used as a replacement for PVC corrugated sheets that have reached their life expectancy and have begun to degrade and break down. In such situations the old glazing is normally replaced using 10mm or 16mm Polycarbonate sheets. These will need to be fitted using some form of Glazing Bar system where the glazing bar will screw down onto the existing timber supports. The two common methods are using a PVC Rafter Bar or an Aluminium Rafter Bar. You can also use self supporting bars if you use 16mm.

Conservatory Roofs

Multiwall polycarbonate became popular with the rise in sales of conservatories. During the 1980’s Wickes and B&Q (and others) produced cheap conservatories which had polycarbonate in their roofs. These were initially glazed with 16mm polycarbonate (some even had 10mm polycarbonate) in the roof but as the industry matured thicker versions of polycarbonate were used, the most popular being 25mm polycarbonate and then 32mm and eventually 35mm sheets.

If you are replacing panels on an old conservatory then you need to make sure theu glazing you have chosen matched the glazing bars you will use. Where you have a Victorian, Edwardian or P Shaped conservatory the panels will need to be cut into shapes. Unless you feel confident measuring the panels (they will need to be removed from the conservatory and placed on the ground to measure) then it would be wise to seek the help of a professional.

The reason the conservatory industry moved to using thicker polycarbonate sheets was because the thicker sheets with their increased number of internal walls gave better sound and heat insulation. If you want to upgrade your own polycarbonate sheets to thicker versions then the whole roof may need to be taken off and replaced with a new conservatory roof as your existing glazing bars may only accommodate the size of polycarbonate used. Thicker sheets soemtimes require different glazing bars. This is obviously a more expensive option to replacing like with like but can result in an “as new” conservatory.

Other Glazing Applications

Because polycarbonate is so light, strong and versatile there really is no end to the type of use it can be put to. The thinner sheets (4mm, 6mm and 10mm) are light and easy to cut and handle so are as useful for internal glazing jobs as they are external ones. The thicker polycarbonate sheets 25mm, 32mm and 35mm tend to be used externally for roofing applications, the thicker the sheet the better the heat and sound insulation. 16mm polycarbonate is light enough to be used for small jobs but also is also useful for certain roofing jobs.

At the end of the day if you are unsure which sheet you should use in a particular application then call us on 01536 446395 or email us on where our experienced staff will be pleased to advise you.