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25mm Polycarbonate Sheets

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25mm polycarbonate sheets are perfect for use in conservatories due to their strength and excellent insulation properties. 25mm polycarbonate is a very high quality glazing material. Including high impact resistance and built in UV protection to protect the sheet from sun damage. Suitable for high end canopies or those jobs requiring bigger spans than 16mm can offer. 25mm polycarbonate sheets from the Glazing Shop come with a 10 year Warranty.

Colours: Clear, Opal and Bronze tints.

25mm polycarbonate is also available in Heatguard and Bronze Opal for even better insulation against heat and cold. Follow this link for information and pricing for these dual-tinted 25mm sheets.

TOTALLY FREE CUT TO SIZE SERVICE - no need to cut on site.

July Savings! -  get a 10% discount off all glazing bars through the whole of July when you buy your polycarbonate from us. Just use the discount code BAR10 at the checkout.

 Please choose your colour then input the length and width you require below :

Availability: In stock

25mm Multiwall Polycarbonate Sheets

This amazing glazing material is manufactured from damage-resistant polycarbonate. 25mm Polycarbonate has excellent insulation values and very high impact resistance. This sheet thickness provides fine optical clarity and has high performance in respect of fire. We recommend the sheets are a maximum of 1050mm width between supports. The UV absorption layer is built into the sheet when it is extruded meaning it has a longer life. Also this layer prevents yellowing of the sheet and loss of strength over time. 25mm Polycarbonate offers excellent protection against vandalism and accidental damage Thereby an impact resistance up to 200 times greater than glass. The Glazing shop 25mm polycarbonate sheets are of the highest quality. In line with this we offer a 10 year warranty for your peace of mind.

Main Benefits

       . Saves energy
       . Lets in plenty of natural light
       . Lighter weight than glass and much more easy to fit
       . Very high level of thermal insulation
    . Impact & Damage resistance
    . Weatherable Longlife UV protection
    . Fire resistance - Class 1 surface spread of flame when tested to BS476 Part 7       
    . Excellent fire performance


       . Conservatories
       . High End Canopies
       . Industrial Rooflights
       . Covered Walkways
       . Swimming Pool Coverings


Tints: Clear, Opal, Bronze

There are also dual tint options available for better thermal insulation. These include 25mm Heatguard and Bronze Opal options.

Glazing bars for 25mm multi-wall polycarbonate

25mm polycarbonate can be used with rafter supported and self-support glazing systems.

Rafter bars need to be screwed into supporting wooden rafters along their length. Self-supporting glazing bars do not need rafter support and are fixed via the eaves beam and the wall plate.

We have a wide range of rafter bars for 25mm polycarbonate sheets with PVC or aluminium capping. We supply these in a range of colours and lengths.

Our self-support glazing bars are also available in a wide range of lengths and colours. These and all the other profiles needed to build a self-supported lean to roof can be found in our self-support system area of the site.

Here are our full range of glazing bars.

Other parts needed for a 25mm polycarbonate roof

Rafter supported roofs require rafter glazing bars as above with a choice of PVC capping or aluminium capping. Your roof will start and end with glazing bars and you will have additional joiner bars between each sheet. With PVC capped bars you will add a universal edge trim to create your end bars and with aluminium capped bars you will need an aluminium F section.

These trims will balance up the empty outside of the first and last bars where there is no glazing. They will also neatly cloak off the ends of your roof. Finally you will need sheet end closures which fix over the antidust tape at the bottom of your sheets to keep out any moisture.

For a 25mm self support lean to roof you will need glazing bars. Self support end bars will be used for the left and right hand sides of your roof, and self support main bars will be needed between each sheet to join them.  You need a wallplate at the back, high end of the roof and an eaves beam for the lower, front end of the roof where your gutter will be attached. You will need sheet end closures to enclose the bottom ends of the polycarbonate sheets. These go on top of the anti-dust tape and prevent moisture from getting into the sheets. If you will be cutting your polycarbonate sheets down on site you will need  anti-dust tape to retape them.


For extra information about all of the thicknesses of structured polycarbonate, their colours, applications and prices, or to place an order, have a look at the polycarbonate sheets pages. Alternatively have a read through our Polycarbonate Buyers guide.


Should you have any questions or need any help at all please call us on 01536 446395 and we will be very happy to help you.

25mm Polycarbonate Technical Information Summary

25mm Polycarbonate Sheet Thickness
  Clear Opal Bronze
U-Value 1.4 1.7*Sunlight 1.4
Light Transmission 62% 20% 15%
Weight (kg per sqm) 3.1 3.1 3.1


Sheet Structure:

25mm multi-wall in an ‘X’ structure.


BS476/7: Class 1

UV Protection:

Yes co-extruded on the top of the sheet. The sheet must be installed the right way up. The bronze side of the bronze-opal sheet faces the sky; the silver-grey side of the heatguard sheet faces the sky.

Cutting Tolerance:

Length & Width: +/-5mm


10 years manufacturer's limited warranty for Clear and Bronze 25mm polycarbonate

10 years manufacturer's limited warranty for Opal 25mm polycarbonate


Additional Manufacturers Technical information 


Please open or download the following pdfs

25mm Opal tint

SUNLITE Polycarbonate Data Sheet SUNLITE Installation Guide Polycarbonate Care and Maintenance - Palram


25mm Clear & Bronze tints

Marlon 25mm Clear Bronze Specification sheet X wall  


Frequently Asked questions

What is 25mm ‘multi wall’ polycarbonate?

Structure of 25mm twin wall polycarbonate

The term multi-wall polycarbonate refers to the structure of the sheet itself. The sheet is made up of many walls and cavities otherwise known as flutes. In 25mm polycarbonate this is known as an ‘X’ structure due to the pattern the walls form through the sheet. The structure makes it lighter weight and easy to handle. It also traps air to make it insulating. This sheet is most widely used for conservatory roofs and other projects where thermal insulation is desired.

Which are the length and width of a twin wall sheet?

Length and width of 25mm polcarbonate sheets

The upper surface of the sheet has a co-extruded UV protective layer, this reduces the penetration of the sun’s rays and prevents discolouration. The sheet must be installed the right way up. Generally, the upper surface of the sheet will have writing on it. Occasionally there is writing on both sides, but one will be marked 'this side up'.

Is there a correct way up for 25mm polycarbonate sheets?

The upper surface of the sheet has a co-extruded UV protective layer, this reduces the penetration of the sun’s rays and prevents discolouration. The sheet must be installed the right way up. Generally, the upper surface of the sheet will have writing on it. Occasionally there is writing on both sides, but one will be marked 'this side up'. 

Do 25mm polycarbonate sheets need to be taped?

Yes, if the sheet will be used in an external location, the open ends always need to be taped to prevent dust and insects getting into the flutes of the sheet. All our 25mm sheets are taped for you at no extra cost. If you need to cut them down on site you will need to buy additional 25mm anti dust tape to retape them.

What colour of 25mm polycarbonate sheet should I choose?

25mm polycarbonate is available in clear, opal and bronze tints. It is also available in dual tints of Heatguard Opal and Bronze Opal.

25mm clear polycarbonate has 62% light transmission allowing plenty of light to shine through. Clear polycarbonate will allow a diffused view of the sky but will show dirt on the roof more clearly than other tints.

25mm opal polycarbonate has a translucent white look quite like that of an opal light bulb. With a light transmission of 20% it allows a softer light through it. The translucency offers excellent privacy from above. It is excellent if you have a canopy that will be overlooked and you wish to obscure the view. This opacity also helps to mask the appearance from below of any leaves or debris that might form.

25mm bronze polycarbonate has a brown / bronze tint. Often used with brown glazing bars and accessories to match brown windows or conservatories. With a light transmission of 15% bronze polycarbonate will give the most shade of the three single tint colours.

25mm heatguard polycarbonate is a dual tinted sheet with a silver-grey upper surface and an opal lower one. Perfect for conservatories where thermal insulation is important, the heatguard surface reflects the sun’s rays to reduce heat build up by up to 50%. It also helps to keep the heat in on colder days. The opal inner surface helps to bounce light around keeping the room lighter.

25mm Bronze-Opal polycarbonate is a dual-coloured polycarbonate sheet with a bronze upper surface and an opal tinted lower one. The bronze surface reflects the sun’s rays and the opal one gives reflective inner light. This dual tint gives excellent  thermal insulation.

What projects is 25mm polycarbonate sheet suitable for?

25mm polycarbonate is suitable for conservatories as it offers more insulation than thinner sheets. It is more cost effective, light weight and easier to handle than glass. It is sometimes used in high end canopies.

The maximum recommended unsupported span is around 1000mm on a rafter supported roof. On a self-supported roof you need to be guided by the bar structural abilities so this may be reduced. The 25mm polycarbonate sheets from the Glazing shop are excellent value - does that make them lower quality?

The 25mm polycarbonate sheets from the Glazing shop are excellent value - does that make them lower quality?

Absolutely not! Our 25mm polycarbonate sheets are from the highest quality extruders. We have been supplying sheets for many years and the amount that we sell allows us to buy economically – we pass theses savings on to our customers. Our 25mm polycarbonate sheets all come with a 10-year manufacturer’s limited warranty.

Is there a warranty with 25mm polycarbonate from the Glazing shop?

All the polycarbonate sheets from the Glazing shop have a 10-year limited manufacturer’s warranty giving you peace of mind.


If you have any other queries that aren't answered here, please give us a call on 01536 446395 and we will be happy to help you.