When ordering multiwall polycarbonate, you may see an option to have your sheets supplied with pre-taped edges. This means protective end tapes are applied to the open channels before delivery, saving you the job of fitting them yourself.
At The Polycarbonate Store, our pre-taping service uses aluminium sealing tape at one end and anti-dust breather tape at the other. These tapes have different jobs, so knowing which end goes where is important.
Which edges are pre-taped?
Twinwall and multiwall polycarbonate contain hollow channels, commonly called flutes, running along the sheet’s length. The tapes cover the two ends where these channels are open—not all four edges of the panel.
For a conventional sloping roof, the flutes run down the slope. The aluminium-taped end belongs at the top, while the breather-taped end belongs at the bottom, towards the gutter.
The upper aluminium tape closes the channels against dirt and water entering through that end. The lower breather tape helps filter out dust and insects while allowing ventilation and moisture to escape. Ordinary packaging tape is not a suitable substitute.
Should you remove the tape before installation?
Leave the correctly fitted aluminium and anti-dust tapes in place. They form part of the sheet’s end protection.
They are different from the temporary protective film covering the broad surfaces of the sheet. That film protects against handling marks and must be removed as directed during installation.
Temporary packaging tape is another separate product. If you are unsure what has been fitted, check with us before removing or covering anything. Manufacturer guidance distinguishes temporary transport seals from the permanent tapes needed for installation.
Do pre-taped sheets still need sheet closures?
Yes. End tape and a sheet closure perform different functions.
The tape protects the open flutes, while the closure fits over the taped end to protect and finish the edge. Pre-taping does not mean a rigid end closure has already been fitted or that the sheet is ready to install without the appropriate accessories.
We recommend closures at the bottom and top ends, with the correct flashing detail at a lean-to wall junction. Read our sheet closure installation guide before fitting.
What if you need to cut the sheets?
Our multiwall polycarbonate sheets are supplied cut to your ordered dimensions, helping reduce preparation on site.
If you subsequently trim a taped end, you will expose the channels again. Remove cutting debris and apply the correct replacement tape to the clean, dry end before fitting its closure. Use aluminium sealing tape for an upper end and suitable anti-dust breather tape for a lower end.
A curved roof where both open ends finish at the bottom needs a different arrangement, typically breather tape at both ends. Tell us about this when ordering so the preparation suits your project.
Ordering pre-taped sheets from The Polycarbonate Store
Our complimentary pre-taping service is available for 10mm, 16mm, 25mm, 32mm and 35mm twinwall and multiwall sheets. Select your preference when ordering, or discuss it with our team if the sheets are intended for something other than a conventional roof.
If you are unsure which option to choose, contact The Polycarbonate Store before placing your order.
FAQs
Does “pre-taped” mean all four edges are taped?
No. It refers to the two ends where the internal flutes are open. The long side edges are finished according to the glazing system.
Are anti-dust tape and breather tape the same thing?
For the lower-end tape supplied with our pre-taping service, these terms describe its combined filtering and ventilating function. It helps limit dirt entering the channels while allowing them to breathe.
Why is there a narrow line near the taped ends?
During pre-taping preparation, approximately 10mm of protective film is removed from each end. This can leave a visible preparation or score line, which the appropriate roofing accessories cover.
If the ends will remain visible in your intended application, request untaped sheets before ordering. If you see a crack or anything beyond the described preparation line, send us photographs before installation.
Does pre-taping prevent condensation completely?
No. Breather tape supports ventilation and drainage, but it cannot guarantee condensation-free channels. See our advice on condensation in polycarbonate sheets for more information.
Can I cover the breather tape with waterproof tape or silicone?
Do not block its ventilating function. Fit the appropriate closure and follow the installation instructions, keeping the required drainage routes open.
Is pre-taping the same as fitting flashing tape?
No. Pre-taping protects the open channels within multiwall sheets. Flashing deals with roof junctions, such as where a lean-to roof meets a wall. One does not replace the other.
