Frequently Asked Questions

Polycarbonate sheeting distributed by Alsynite is available throughout New Zealand from most hardware merchants and metal rollforming companies.

Polycarbonate

Do you cut polycarbonate sheets to length?

We have a full range of standard stock sheet lengths, but we can cut down sheet to suit your project requirements.
Standard lengths 1.8m, 2.4m, 3.0m, 3.6m, 4.2m
Special order lengths 2.1m, 2.7m, 4.8m, 5.4m, 6.0m, 7.2m

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

No, we will cut to length if requested, but it should be noted that cut-back sheet lengths will be charged to the next sheet increment.

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. Scrub down with a soft brush. 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 selection e.g. clear and antique bronze?

No. The cost that is quoted for a particular brand and profile will be the same cost across the range of colours.

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

The lifetime warranty varies between products. The Laserlite® brands (2000+ and 3000) are superior products with improved performance. The new Laserlite® 2000+ range has a light transmission warranty of 15+ years, whereas the SolarTuff® brand has 10+ years’ warranty. Laserlite® 2000+ and Laserlite® 3000 are the only products to have Australian Standard Certification (AS4256. 5). This means that the product complies with a set standard to meet the requirements for transparent, translucent and opaque polycarbonate sheeting intended for use as roof or wall cladding. It is important to check that products are 99.9% UV resistant if you are looking for sun protection.

What is recommended to complete the job?

Using Laserlite® One Shot fasteners and Laserlite® purlin 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 required to complete the 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.

DIY Installation Questions

  1. How many sheets of roofing should I purchase?
  2. What is my overall roof area?
  3. How many fixings/fasteners do I need?

Example scenario: replacing a veranda roof

1. I should purchase X roofing sheets

If I want to replace sheeting on an existing veranda that is 2.3m in length, then I need to purchase 2.4m sheet, as this is the next available sheet length, and 1.8m is too short.

2. My overall roof area is Xroof measurement

My veranda is 4m wide. I need to purchase 2.4m sheet lengths (2400mm) and the effective cover with side laps allowed for is .76m (760mm)

Calculation :
4m ÷ 0.76m = 5.26 sheets (round up to whole sheets, so we need six sheets at 2.4m lengths).

3. I should purchase X roofing fasteners

For each 2.4m sheet allow seven fasteners, then multiply by six sheets to cover area = 100.8. Round up to the next whole number, so 101.* [2.4m x 7 x 6]
*Note: fasteners come in different pack or jar sizes, so you will need to check with your retail store.

How do you prevent leaking?

A minimum pitch of 5° is recommended. Below 5° may result in the roof leaking. (88mm rise per lineal metre = 5° pitch). Also ensure that you have the correct side laps. For Corrugate/Roma profile, ensure a 1 ½ side lap, and for Greca and Trimdek 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, and people 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. If you use flashings and back channel tape instead, then this will make the job watertight. If you must use a sealant you need to use one that is compatible with the sheeting – Holdfast make one called Crystal Clear.

Fasteners

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?

There are special fixings available to purchase for high wind loads. It is recommended that you seek advice based on your high wind area as you’ll need to check profile washers, which is normally a low spreading washer.

Insulation

Do we install insulation?

Alsynite do not install insulation. We can provide you with a list of our recommended installers in your area/region. We recommend using a professional, approved installer, which will result in high safety and quality standards so the insulation performs properly and keeps your home warm.

There is funding available through the EECA Energywise government scheme Warm Up New Zealand: Heat Smart. If you are interested, to find out more go to www.energywise.govt.nz

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