Technical Information
Fire
The thermoplastic glazing materials have been tested in accordance with the relevant British Standards with the following results:
| Test |
Polycarbonate |
Standard Acrylic |
PVCu |
| BS 2782: 1970 Method 508 A |
Flame retartant |
Not flame retardant |
Flame retardant |
| BS 2782: 1970 Method 508 D |
Very low flammability |
Flammable |
Very low flammability |
| BS 476: Part 7: 1971 Surface spread of flame (or 1987) |
* Class 1 (see note) |
* Class 3 |
* Class 1 |
| BS 476: Part 8: 1972 Fire resistance of elements of building construction |
** Less than 1/2 hour |
** Less than 1/2 hour |
** Less than 1/2 hour |
| BS 476: Part 3: 1958 External fire exposure roof tests |
AA |
DDX |
Not applicable |
| Building Reg. Appendix A Approved Document B |
TP(a)* |
TP(b)* |
TP(a)* |
* when tested in 3mm thickness and over ** Assumed results
Note: Materials which achieve class IY can be regarded as having an AA designation
Weight
3mm Polycarbonate - 4.5kg/m2 3mm PVCu - 4.5kg/m2
Relative Impact & Breakage Resistance
6mm Georgian Wired Glass 3mm PVCu - approximately 50 times stronger than the glass 3mm Polycarbonate - unbreakable within the limits of the test comparison
Thermal Transmission (U Value)
Polycarbonate Single Skin - 3mm 5.4w/m2/degree C Polycarbonate Double Skin - 3mm 2.6w/m2/degree C
Light Transmission (Based on 3mm)
Polycarbonate clear - approximately 82% Polycarbonate opal - approximately 50%
PVCu
Clear - approximately 85% Opal - approximately 72%
Cast Acrylic
Clear - approximately 92% Opal - approximately 78%
All Astrofade rooflights can be supplied in bronze to control solar gain and glare
| Material |
Light Transmission |
Total Solar Energy Transmission |
| Bronze Polycarbonate |
50% |
55% |
| Bronze PVCu |
60% |
69% |
