Which Polycarbonate Sheet Do You Need?

Since introducing our Clear Amber roofing sheet range in March, the most popular option by far are the polycarbonate sheets. We know that with the different options, thickness, colours and styles you can easily be overwhelmed by choice and not know where to start. So we are going to cover common questions about choosing polycarbonate for your project, comparing alternatives, installing polycarbonate and more!

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So whether you are building a lean to roof, pergola roof or car port, polycarbonate sheeting will likely be one of the top roofing options you will consider and after reading this blog, you will (hopefully) know the best option for you. As a lightweight, stronger and arguably safer alternative to glass, polycarbonate is a cost-effective roof glazing solution that is easy to install whilst also creating stunning finish and so we will go over what it is, why it is good (and sometimes bad) and how to choose the correct roofing sheet for your upcoming project. 

What is a polycarbonate sheet?

Polycarbonate Sheets are popular compared to other lower grades of plastic sheets due to their durability and incredibly easy to install properties. As such, they are confidently used in millions of installations every year. 

Where can polycarbonate be used?

There are numerous uses that you may have already encountered today. Whether in a residential or commercial setting, it offers the flexibility to be utilized in a variety of applications such as canopy glazing, lean tos, carports, and protective barriers in public spaces. Its main purpose, and likely the reason you are reading this blog, is as a dependable roofing material. From lean tos and pergolas to greenhouses and orangeries, Polycarbonate reigns as the top choice for a diverse range of structures.

What types of polycarbonate sheeting are there?

The two types of polycarbonate sheets that Dry Verge & Roofline Direct offer: solid polycarbonate and multiwall polycarbonate.

Dont be put off by the amount of styles in the multiwall range. You can choose between Twinwall polycarbonate sheets and multiwall polycarbonate sheeting. These are the same thing, it's only the number of internal walls that set them apart.

Both solid and multiwall sheets boast durability and ease of installation, so your decision should be based on aesthetic appeal, budget, and strength.

What is Solid Polycarbonate?

Being 200x stronger than regular glass of equal thickness, solid polycarb sheets are virtually unbreakable, yet weigh only half as much. With a range of thicknesses from 2 to 12mm, including popular 6mm, solid polycarbonate sheets come in a variety of tints for all your needs, such as clear, bronze, opal, black, and patterned.

Have a look at the helpful Clear Amber Video below for more info:

What is Multiwall polycarbonate sheeting?

Multiwall polycarbonate sheets are made up of layers that create a honeycomb structure. This type of sheeting is widely used and is the most cost-effective option for polycarbonate, as well as providing excellent thermal insulation. Similar to Solid Polycarbonate sheets, multiwall polycarbonate is available in a variety of tints including clear, bronze, and opal. The most commonly used thickness for multiwall polycarbonate is 16mm.

What is Twinwall Polycarbonate?

Twinwall Polycarb sheets come in 3 thicknesses - 4mm, 6mm, and 10mm - providing a range of strength options for any roofing project/need. With just two layers, Twinwall polycarbonate offers the same quality as multiwall sheets but with just two layers- as the name suggests and is primarily used for smaller projects.

It is worth noting that 4mm & 6mm polycarb sheets are not recommended for roofing projects. Instead they are preferred as cost-effective plastic sheeting for smaller garden applications like cold frames.

So What is the difference between Twinwall & Multiwall?

Twinwall Polycarbonate Sheeting is extruding with two external layers and internal connectors. On the other hand, multiwall polycarbonate sheets have two external layers and then multiple internal layers, ranging from 3 layers total upwards.

The thicker the sheet the more walls they tend to have. 4mm, 6mm and 10mm thickness are considered to be Twinwall and 16mm, 25mm and 35mm are Multiwall. Thicker gauge sheets have better thermal insulation (lower U Value) Also thicker multiwall sheets tend to have greater sound reduction compared to the thin 6mm and 10mm, although this is less of a factor.

Benefits of Polycarbonate Sheeting

• Virtually unbreakable
• Lightweight
• Easy to cut & drill into
• Long-lasting clarity due to UV Protection
• Insulating
• Fire-resistant

Virtually unbreakable: A key benefit of polycarbonate sheets is their robustness and impact resistance which means they are virtually unbreakable!

Lightweight: Ease of installation is key when you are choosing a roofing sheet to use and a big part of that is weight. Heavy options like glass can cause handling challenges, especially when high up on a roof.

Long-lasting clarity: UV protection is important on clear roofing sheets to ensure long lasting clarity and light transmission. All of the Clear Amber polycarbonate sheets are UV protected on one or two sides to give a great roof lifespan! UV protected sheets are not to be confused with UV stable or UV resistant which are seen on some sheets (like PVC) and aren’t as effective.

Insulating: Polycarbonate naturally retains heat very well and so has great thermal insulation qualities. Multiwall polycarbonate in particular provides great levels of thermal insulation.

Sustainable: Polycarbonate roof panels are fully recyclable!

Fire-resistant: Polycarbonate is fire resistant and (unlike acrylic) is self-extinguishing.

Easy to cut and drill: Another area polycarbonate shines in is how easy it is to cut and drill. 

What are the disadvantages of polycarbonate?

Polycarbonate sheets have minimal drawbacks, making them a highly sought-after roofing option. The only drawback is their potential for scratching if not treated with care. However, this can be easily avoided with the use of protective film on both sides of the solid sheets during installation. Once installed, the protective film can be conveniently removed.

Can you bend polycarbonate sheets?

Yes, polycarbonate sheeting can be bent and installed on a curved roof. It is quite easy to install with curved glazing bars. As a rule of thumb, the thinner gauge sheets bend more easily.

What thickness of polycarbonate should I use?

When choosing a polycarbonate sheet thickness there are two main factors to bear in mind; strength & insulation. Quite simply, the thicker the sheet the greater the strength & higher thermal insulation. 

See below the common uses for each thickness as inspiration:

Solid Polycarbonate

2 mm – Wall protection, Secondary glazing

3 and 4mm – Screens, Bike shelters, curved dugouts, shed windows

5 and 6mm – Oak Pergolas, canopies, lean tos, gazebo glazing

8,10 and 12mm – lean tos, verandas

Multiwall Polycarbonate

4mm – cloches and temporary glazing (not suitable for roofing applications)

If you want to learn more, please visit our website 4mm solid sheet.

6mm - cold frames and greenhouses (not suitable for roofing applications)

10mm – potting sheets, pergolas

16mm – lean to, gazeboes, canopies, carports

25mm – lean to extension, garden buildings

35mm – conservatory roofs, orangeries, extensions

When choosing the correct sheet for your roofing project, it is always dependent on YOUR project’s factors, such as the location, wind, exposure, structure and so on.  So you are always best to make a judgement based on your project! 

Check the Clear Amber overview tables below for a complete comparison of colour types to further support your decision.

Polycarbonate is an extremely versatile type of plastic that can be used in a wide variety of applications. More specifically, in terms of composition, polycarbonates are a group of thermoplastic polymers that contain carbonate groups within their chemical structures. Polycarbonate is a strong material, yet because it's comparatively lightweight, it's straightforward to transport and install. Naturally transparent, polycarbonate is also available in a range of colours. It is easily worked, moulded, and thermoformed.

The history of Polycarbonate

Polycarbonates were first discovered in by Alfred Einhom, a German scientist working at the University of Munich, however after 30 years' laboratory research, this class of materials was abandoned without commercialization. Researched resumed in , when Hermann Schnell at Bayer in Germany patented the first linear polycarbonate and subsequently the brand name "Makrolon" was registered later in . Up until Polycarbonate was produced with a brownish tint, however after significant improvements in the manufacturing process it became possible to produce glass-clear polycarbonate which led to far greater commercial demand for the material. 

The properties of Polycarbonate

Polycarbonate's many positive properties are the reason why it's so often chosen over other forms of plastic sheeting. First and foremost, polycarbonate is tough and highly resistant to impact. Polycarbonate is up to 200 times stronger than glass, and is considered to be almost unbreakable, which makes it a much safer and more secure option for high-traffic areas. It is also particularly suitable in both commercial and residential glazing applications. In addition, polycarbonate’s durability translates into excellent longevity, which in turn makes it a great long-term investment.

Lightweight and malleable

Despite its strength, polycarbonate is lightweight, so it's cost-effective to ship, easy to handle, and needs less support than heavier alternatives to hold it in place. These properties illustrate why polycarbonate is an excellent option for greenhouses, secondary glazing and a variety of other glazing applications.

Another big positive of polycarbonate is that it's one of the easiest types of plastic sheet to process – unlike many other plastics, polycarbonate can be easily cut, drilled, and formed without cracking or breaking. It can be shaped or bent at room temperature, however typically in a commercial environment it would be cold formed/bent and then heated to ensure that the material doesn't spring back to its original form. These properties make Polycarbonate suitable for a wide variety of fabrication processes and applications.

Clarity and insulation

Polycarbonate offers superb long-lasting clarity and excellent light transmission that's comparable to traditional glass. However, while it lets the light through, it keeps the elements out. That's because polycarbonate is an effective thermal insulator. It retains more heat than both traditional glass and its acrylic counterpart – a quality that makes it particularly suited for use within secondary glazing, home extensions and conservatories.

Polycarbonate's K- and U-values are a useful indication of its insulation properties. A material's U-value measures heat loss through a given thickness of a building, roof, wall or floor. In general terms, the lower the U-value, the better the material in question is as a heat insulator. A material's K-value refers to its ability to conduct heat. A low K-value is advantageous for insulating materials, as this means heat energy cannot easily pass through. As the table below illustrates, polycarbonate out-performs glass in both regards. Traditional single pane glass has an average K value of 0.96 whereas our Polycarbonate sheets have a K value of 0.21 which demonstrates why Polycarbonate provides superior insulation to traditional glass, in addition to being cheaper and easier to install and maintain.

UV and fire resistance

Yet another advantageous property of polycarbonate is its UV-resistance. In addition to withstanding all sorts of harsh weather – even snow and heavy rain – polycarbonate filters out a large proportion of harmful UV rays that glass allows through. This is good news for greenhouses, as it prevents plants from UV damage. Like most UV polycarbonate material, our Palsun Solid Polycarbonate Sheets are UV-protected on one side, which significantly improves long-term weatherability. A comparison of the UV protection offered by PALSUN and that offered by sunscreen cream 15 is depicted in the graph below.

100% recyclable

In contrast to single-use plastics which contribute significantly to plastic waste, our Palsun Polycarbonate portfolio is 100% recyclable, to help create a more sustainable environment. Furthermore, each sheet contains up to 30% recycled content.

What can polycarbonate be used for?

The multipurpose properties of polycarbonate mean it is a highly versatile material that can be used in many different ways. It's most commonly used for roofing and glazing (both primary and secondary), and especially for greenhouses, conservatories and orangeries. More recently, during the COVID epidemic, polycarbonate was also used for sneeze screens and safety guards. Other typical applications include:

• Sky lights
• Construction
• Automotive and aircraft components
• Security components
• Signage
• Vending machines
• Street furniture
• Machine guards
• Lighting 
• Roof domes
• Bicycle racks

The different types of polycarbonate

We offer four main types of polycarbonate – solid sheet, prismatic, multi-wall/twin-wall and Georgian wire.

As its name suggests, solid clear polycarbonate sheet looks just like glass but, is stronger and lighter. It offers 89% light transmission and is available in a range of thicknesses, from 1mm to 12mm. We also stock Opal Polycarbonate which is available in 2mm, 3mm and 5mm gauges.  The maximum sheet size available is mm x mm.

Prismatic polycarbonate sheet incorporates a textured pattern on one side, which is optimised for both light transmission and diffusion, making it a popular choice for lighting applications. Its aesthetic appeal also works well within interior and exterior decoration, and exhibition displays. The maximum sheet size is mm x mm and it is available in a 3mm thickness.

Multi-wall polycarbonate sheet features multiple layers which form a honeycomb-like structure. It offers superb thermal insulation (and relatively good sound insulation), making it a popular choice for conservatories, greenhouses, carports, and lean-to extensions. Twin-wall polycarbonate is similar to multi-wall, except it has just two layers instead of several. It is a popular choice for smaller projects such as cold frames and cloches. Both products are available in clear, opal and bronze.

Frequently asked Questions

- What is the lifespan of Polycarbonate?
With proper care, polycarbonate should last at least a decade. The polycarbonate we supply is guaranteed against discolouration for 10 years.

- Which is better: polycarbonate or acrylic?
It depends on the intended usage. These materials share many similar properties. Polycarbonate is much stronger and more flexible than acrylic – but it's usually more expensive. In terms of appearance, acrylic is glossier and marginally more transparent. Polycarbonate also scratches easier than acrylic.

- What is the best thickness for polycarbonate?
Again, it all depends on the intended application. For example, thicker sheets (25mm, 32mm and 35mm) of twin/multi wall are the best option for external roofing applications. For greenhouses, cold frames and secondary glazing thicknesses of 3mm, 4mm and 5mm are the most popular choices.

- Does polycarbonate discolour?
Because they are resistant to temperature extremes and UV light, polycarbonate panels should not fade or discolour for many years. Cheaper versions may yellow over time.

- How do you clean polycarbonate?
Polycarbonate should be cleaned gently, with warm water, a few drops of liquid detergent, and a microfibre cloth.

- What are the disadvantages of polycarbonate?
There really aren’t many! It can scratch if it isn’t handled carefully, and it can’t be laser cut.

Contact us to discuss your requirements of 5mm solid sheet. Our experienced sales team can help you identify the options that best suit your needs.

Why choose us for your polycarbonate needs?