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Frequently Asked Questions

  • Polycarbonate
  • Installation
  • Fasteners
  • Insulation
Where can I purchase Alsynite One’s polycarbonate sheeting products?

Polycarbonate sheeting products are distributed by Alsynite One NZ Ltd and are available throughout New Zealand from most hardware merchants and metal roll-forming companies. Find our partners here.

Do you cut polycarbonate sheets to length?

Whilst we have a full range of standard stock sheet lengths, we will happily cut down sheets to suit your project requirements.

Our Standard lengths: 1.8m, 2.1m, 2.4m, 2.7m, 3.0m, 3.6m, 4.2m, 4.8m, 5.4m, 6.0m, 7.2m

Is there any additional cost to cut sheet lengths to specific requirements?

No, we will cut polycarbonate sheets to any length you require, but please note that cut-back sheet lengths will be charged to the next sheet increment i.e if you require a 2.3m length you will need to purchase 2.4m length.

In DIY projects, what is the best method to cut sheet to guarantee a smooth edge?

A fine-toothed handsaw or circular saw with a cut-off blade is suitable for plastics. Always wear eye protection when using cutting tools.

Can I walk on polycarbonate sheet?

No, never walk on sheeting or apply your load directly to it.

What can you clean polycarbonate or PVC sheet with?

Clean your roof with warm soapy water (mild detergent) and a soft sponge. First scrub down the sheet with a soft brush, then hose down thoroughly. Do not use a water-blaster as this will remove a layer of the UV cap and reduce the life expectancy of the product.

Does the cost vary between colour selections; e.g., clear and antique bronze?

No, the cost quoted for a particular polycarbonate sheet brand and profile will be the same cost across our range of colours.

What’s the difference between polycarbonate products, for example Laserlite® and Sunline®?

The lifetime warranty varies between products. The Laserlite® brands (2000+ and 3000) are superior products with improved performance. The Laserlite® 2000+ range has a light transmission warranty of 30 years, whereas the Sunline® brand has 15 year warranty.

Laserlite® 2000+ and Laserlite® 3000 are the only products to have Australian Standard Certification (AS4256. 5). These products comply with a set standard to meet the requirements for transparent, translucent and opaque polycarbonate sheeting, intended for use as roof or wall cladding. If you require sun protection, check that products are 99.9% UV resistant.

What is recommended to complete the sheeting job?

Using Laserlite® One Shot fasteners and Noise Stop Tape will ensure that the sheeting is properly fastened and allowed to sit on the purlins better, reducing expansion and contraction noise caused from varying ambient temperatures. Don’t forget the flashings, ridging and back channel.

How do I stop the sheet from creaking?

Laserlite® Noise Stop Tape is a foam product that goes between the purlins and the sheeting, which prevents any creaking.

How do you calculate how many sheets are required to complete a job?

Side laps need to be considered when calculating how much sheet you need. Calculate the number of sheets required based on the effective cover width (once fitted), as opposed to actual sheet width. For example, a standard 840mm sheet has an effective sheet cover width of 760mm.  Please see the example below and or see our roofing calculator.

How do you prevent leaking?

A minimum pitch of 5° is recommended. (88mm rise per lineal metre = 5° pitch). Below 5° may result in the roof leaking. Also ensure that you have the correct side laps. For Corrugate/Roma profiles, ensure a 1 ½ side lap, and for Greca and 5-Rib ensure a single side lap.

Can I use polycarbonate for a fence?

Yes, but make sure you orientate the UV protected side to the sun. Ideally, position the fence facing North.

What sealants can I use on polycarbonate?

We do not recommend the use of sealants on polycarbonate for the following reasons:

– they can damage the UV cap layer
– people often try to stick the side lap together, which prevents the sheets from expanding and contracting.

The life of sealant is short compared to the life you get from polycarbonate sheets. If you use flashings and back channel tape instead, you will ensure your work is watertight. If you must use a sealant you need to use one that is compatible with the sheeting. Holdfast make a sealant called Crystal Clear.

What sheet length should I purchase for replacing a veranda roof?

If your existing veranda is 2.3m in length, you need to purchase 2.4m length sheets. The 2.1m length sheet is too short.

What is my overall roof area if it is 4m wide by 2.3m deep?

In this example you need to purchase 2.4m sheet lengths (2400mm). The effective cover with side laps allowed for is 0.76m (760mm).

Your calculation would be worked out like this:

4m ÷ 0.76m = 5.26 sheets

Rounding up to whole sheets, you would need 6 sheets at 2.4m length.

How many roofing fasteners should I purchase?

For each 2.4m sheet allow 7 fasteners, then multiply by 6 sheets to cover the area = 100.8 (2.4 x 7 x 6 = 100.8). Round up to the next whole number, so you require 101 fasteners*. 

*Note: fasteners come in different pack or jar sizes, so you will need to check with your retail store.

How many fasteners do I need?

The general rule is to allow seven fasteners per lineal metre of sheet.

What spacing should each fastener have?

Screw every second rib on the end purlins and every third rib on the intermediate purlins.

What type of fixings do I need in high wind areas?

Special fixings are available for high wind loads. Please seek advice for your circumstances as you’ll need to check profile washers, which is normally a load spreading washer.

Does Alsynite One install insulation?

No we don’t install insulation, but we can provide you with a list of recommended installers in your area/region. Always use a professional, approved installer, which will result in high safety and quality standards, to ensure your insulation performs properly and keeps your home warm.

There is possible funding available through the EECA Energywise government “Warm Up New Zealand: Heat Smart” scheme. If you are interested in this insulation program visit

What is an R-value?

All insulation materials are rated for their performance in restricting heat transfer. This is expressed as the R-value, also known as thermal resistance or resistivity.  The R-value is a guide to its performance as an insulator – the higher the R-value, the greater the insulating effect. R-values are expressed using the metric unit’s m2/K/W, where:

  • m2 refers to one metre squared of the material of a specified thickness;
  • K refers to a one degree temperature difference (Kelvin or Celsius) across the material; and
  • W refers to the amount of heat flow across the material in watts.

Products that have the same R-value will provide exactly the same insulating effect as each other, provided they are correctly installed.

Still have an unanswered question?

If your question hasn’t been answered here, please get in contact with us and we’ll do our best to answer your query.

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