Polycarbonate Multiwall Sheets Installation Intructions

General Guidelines


PC sheets should be stored to protect from weather conditions such as sun, rain, etc.

The sheets should be stacked horizontally to avoid any unsupported overhang and should be supported on timber bearers.


As with any glazing material, scratches and damage to sheet edges should be avoided during handling.


PC sheets can be cut easily and accurately with standard workshop equipment.  Use circular saws with a fine-toothed blade.  Blow away saw dust off the channels with dry, compressed air.  Take care to ensure that no saw dust is blown inside the sheet channels.


Holes can be drilled using a power drill equipped with a standard high speed twist drill bit.


Only use regular non-alkaline soaps, warm (not hot) water, and soft sponges.



Thermal Expansion

You should allow for thermal expansion both length and width wise.  In general, approximately 3 mm per each meter should be secured to allow for a temperature difference of 50ºC.

Sheet Edge Clamping Conditions

It is extremely important that the edges of the sheet are correctly secured.

In general the total rebate depth for each profile should include a min. of 20 mm sheet edge engagement and an allowance for thermal expansion.

Screws are not recommended.

Open End Sealing

The upper sheet end should be sealed with aluminium adhesive tape.  It is recommended that the lower end be sealed by a special aluminium tape with micro perforations ('vent tape') to avoid insects and dust from getting into the channels, while also allowing water vapour to get out.


Neoprene, TPE, or EPDM rubbers with an approximate shore hardness of A65 are recommended for their compatibility.  Silicone sealants are also generally not recommended.  When using other sealants check their chemical compatibility with polycarbonate.  DO NOT USE PVC gaskets as the softeners can attack the polycarbonate.


The sheet should always be installed with the channels sloping downwards.

Sloped roofing

For sloped applications a minimum slope of 5° (9cm/m sheet length) is advised to allow rainwater drainage.


Site safety

On roof constructions the sheet should not be used to support a person's weight. A temporary wooden beam or other device, supported by the roof members, should always been used.