Suntuf Twinwall FAQ's


How important is it to follow the PSP Twinwall general recommendations on product usage?

Very important. Recommendations for the storage, installation and general treatment of Twinwall sheets are drafted to ensure that the product’s quality and serviceability is met to full extent, and following these recommendations ensures that product warranty isn't void.


Can I use silicone to seal Twinwall?

Silicone sealers and adhesives can be used if they are neutral cure, also check with the manufacturer if they are compatible with polycarbonate plastics.


How do I cut Twinwall sheets?

Twinwall sheets may be cut with either a circular saw (using a very fine blade, e.g. Irwin Marathon PVC blade.) or a fine bladed jig saw. For best results it is often better to cut a few sheets at a time to reduce vibration. Sheets may also be cut by hand by carefully using tin snips, heavy duty scissors or a utility knife. For further information please refer to the Twinwall installation manual.


What should I use to clean my panels?

Warm water with a mild household detergent should be sufficient to clean Twinwall sheets. Wipe off any remained dirt with a soft cloth and wash again. Low pressure water blasting is also suitable only when the nozzle is kept at least 500mm from the sheet. NEVER use a solvent based cleaner (ammonia, etc.). NEVER wipe the sheets when dry. Always test an unseen area first before a total roof clean.

AVOID using sponges or brushes that can scratch the sheets surface.


Is it OK to walk over roofing sheets while in storage, during or after installation?

No. For more safety information visit


How many fastening options are there? And what is best for my installation.

Use Twinwall screws and ensure to pre-drill a 6mm hole and fix at every 300mm along the edge of purlins/rafters and every 500mm of internal purlins/rafters


Do Twinwall sheets keep the "heat" out?

Twinwall also uses SolarSmart technology, reducing solar heat and glare, providing a comfortable outdoor area


How long is the Twinwall warranty?

We offer a 10-year limited warranty on our Twinwall products


Is it OK to fix screws by a power drill or screwdriver?

Yes, use Twinwall Stainless Fixings with rubber washers. Unsure not to over fix to avoid cracking the Twinwall


What is the weight of typical Twinwall panels?

A 4mm thick panel has a weight of 0.8kg/m^2


How should I store packed Twinwall sheets?

Store sheets in a protected, shaded, ventilated site, with no direct exposure to sunlight and winds. For outdoor temporary storage, cover with an opaque protective tarp, avoiding heat-absorbing materials.


Can these sheets catch fire?

Twinwall has a Group 1s Fire Rating. Please contact PSP for further details.


Do the sheets expand in heat?

Yes, polycarbonate sheets expand with heat, and contract with cold.


Do Twinwall roofing sheets really block UV radiation?

Yes, Twinwall blocks virtually all UV radiation


Should I paint the topside of structural rafters and purlins with any paint?

We do recommend that the topside of the purlin is painted a light colour to avoid heat absorption.

Product & Installation Information