1. What is Venetian polycarbonate?
Lexan Thermoclear Venetian is a multiwall sheet which has been screenprinted with white stripes on the non-uv coated side. The white stripe should always be installed facing inwards, the other side, clearly identified as protected against UV, being installed facing outwards. The white stripes are primarily there for decoration but they also help in reducing glare and heat build up inside a room.
2. What is the minimum pitch for a polycarbonate roof?
Never install polycarbonate flat. Our standard glazing systems require a minimum pitch of 5° to ensure water can run off the roof and to eliminate ‘puddling’. Our Multi-Link-Panel modular system should be installed with a minimum 10° pitch. Contact us if you require clarification.
3. Can you walk on polycarbonate sheet?
Polycarbonate has been tested against UK wind and snow loads and we can supply you with recommended glazing centres for each thickness of polycarbonate. However you should never walk directly on polycarbonate sheet. A crawling board or similar should be placed across at least two structural supports of the roof. We can manufacture aluminium framed polycarbonate panels which have been tested for non-fragility to ACR(M)001:2014 – this does not mean you can walk on the polycarbonate but gives added resistance to accidental falls.
4. How do you cut multiwall polycarbonate sheet?
Multiwall polycarbonate can be cut easily and accurately with standard workshop equipment including common circular, hand and hacksaws. When cutting multiwall polycarbonate saw dust should be blown out of the flutes using dry compressed air. Circular saws should have fine-toothed blades. If you are cutting with hand or power hacksaws always make sure the sheet is clamped to a worktable. After cutting and blowing air through the sheets, the flutes should be taped with an anti-dust breather tape at the eaves (lower) end of the roof and with a blanking tape at the ridge (upper) end.
5. How do you fix multiwall polycarbonate sheet?
We can supply you with glazing systems to secure the polycarbonate to your roof depending on the type of roof you have. We have rafter gasket systems for fitting onto rafters or structural systems to fit across purlins and even systems that can span up to 4 metres between fixing points. We also carry the accessory trims and profiles needed to finish the roof of as well as many of the fixings needed to secure the glazing system to the supporting structure.
6. How much allowance do I leave for expansion and contraction?
Thermal expansion of the sheet is 3mm per linear metre. When you talk to us about your application, we will quote you the recommended glazing centres and quote you the cut width of the polycarbonate sheet which allows for the expansion and contraction.
7. How do you clean polycarbonate sheet?
Gently wash the sheet with a solution of mild soap and lukewarm water, using a soft, grit free cloth or sponge to loosen any dirt or grime. Rinse over with clean water to remove any residue. NEVER use a proprietary glass cleaner.
8. What is the life span of multiwall polycarbonate sheet?
The manufacturers of multiwall polycarbonate sheet offer a ten year written limited warranty on the product which covers discolouration, loss of light transmission and loss of impact strength due to weathering. That does not mean that after 10 years the sheet will fail, we have installations that have been in situ longer than 10 years with no obvious detrimental affect either in appearance or performance.
9. How much light does multiwall polycarbonate let through?
Taking 16mm triplewall polycarbonate as an example, clear sheet has a light transmission of 74%, opal has 62% and bronze has 30%
10. What is the fire performance of polycarbonate?
Polycarbonate has good fire behaviour characteristics and receives high ratings in several major European fire performance tests including EN13501. Always check with the Twinfix sales office for current classification, at the time of writing most variants achieve a class1Y when tested against BS476 part 7 surface spread of flame.
11. How does UV affect polycarbonate?
Solar radiation has a particularly harmful effect upon materials that are not protected. Many variants of multiwall polycarbonate have a unique proprietary UV-protected surface on one or both sides, giving excellent resistance to outdoor weathering. This unique protection ensures long-term optical quality under intensive UV exposure.
12. What centres should I be using when glazing multiwall polycarbonate on a roof?
Although it is made in very wide panels, multiwall polycarbonate is only lightweight and as such there are maximum widths it should be glazed at, based on UK wind and snow loadings, as follows:
10mm = 700mm wide panels
16mm = 1000mm wide panels
25mm = 1250mm wide panels
13. Polycarbonate is virtually unbreakable, so isn't polycarbonate glazing non-fragile?
No, in many canopies that use multi-wall or solid polycarbonate glazing, the glazing is simply clamped into a glazing bar system that just holds these sheets in place. Whilst the sheet itself might not break, a falling object, (and in some cases even a strong wind), can flex the sheet and force it out from between the glazing bars. If someone were to trip on such a roof, they could fall through, endangering themselves and anyone underneath. Remember..... just because it doesn't break doesn't make it non-fragile.