Technical Notes 66 & 67 produced by the Centre for Window and Cladding Technology (CWCT), are recognised as the only glass specific performance guidelines, covering the design and destructive performance testing of low pitch glazed roofing.TN66 & TN67 require each individual application to be assessed, and SkyLight Solutions can design rooflights to be fully compliant with Class 2, and certifed by project specific independent testing when required.
Rooflights complying with CWCT TN67 Class 2 are designed to protect people walking adjacent or undertaking maintenance work on the glazed roofing, from falling through.
Unlike the ACR[M]001:2005 test, designed for thermoplastic rooflights, the CWCT test includes both soft and hard body tests, on both the outer and inner panes of glass, followed by a static load test of up to 180kg for a period of 30 minutes. CWCT TN 66 & 67 Test Sequence. Test Stage No. Details of Test Roof Class 2 1 The test sample is prepared to the specified conditions. The test is carried out at the maximum service temperature of the installation. 2 A soft body test is undertaken on the outer pane of glass This is to simulate a maintenance operative accidentally falling onto to rooflight from a standing position. This test is carried out with a 300mm sand bag weighing 45kg, dropped from a height of 1.2m. The glass is allowed to break, but the impactor should not fall through. 3 A hard body test is undertaken on the outer pane of glass. This test is to simulate tools or equipment falling onto the rooflight. This test is carried out with a 100mm diameter steel ball weighing 4.1kg, dropped from a height of 1.2m. The glass is allowed to break, but the impactor should not fall through.View video of stage 3 of the test - Hard Body Impact test If the above tests do not break the outer pane, then it should be broken prior to proceeding to Test 4. This is undertaken, as the glass could still break in a real situation. 4 A soft body test is undertaken on the inner pane of glass, as previously undertaken in Test stage 2. The glass is allowed to break, but the impactor should not fall through.View video of Stage 4 of the test - Soft Body Impact Test. 5 A hard body test is undertaken on the inner pane of glass, as previously undertaken in Test stage 3. The glass is allowed to break, but the impactor should not fall through. 6 This stage is only applicable to single glazed applications. 7 Any unbroken plies of glass should be broken. A static load weighing up to 180kg is applied to the glass, and left in position for 30 minutes. The actual weight is to be determined by the competent person overseeing the testing. This test is to simulate the weight of a person (90kg) who has fallen onto the rooflight and become injured. Depending on the design of the rooflight, the weight of a second person (90kg) giving assistance should be allowed (180kg) total weight. The 30 minute period is to allow for assistance to arrive to rescue the injured person. 8 Any glass fragments that have fallen during the testing are assessed. The glass fragments should not exceed 50mm in any direction, and the total weight of al fragments should not exceed 50g. 9 Repeat the test sequence on any glass units still to be tested. 10 Repeat the test at different specified temperatures.
CWCT TN 66 & 67 Test Sequence.
Test Stage No.
Details of Test
Roof Class 2
1
The test sample is prepared to the specified conditions.
The test is carried out at the maximum service temperature of the installation.
2
A soft body test is undertaken on the outer pane of glass
This is to simulate a maintenance operative accidentally falling onto to rooflight from a standing position. This test is carried out with a 300mm sand bag weighing 45kg, dropped from a height of 1.2m. The glass is allowed to break, but the impactor should not fall through.
3
A hard body test is undertaken on the outer pane of glass.
This test is to simulate tools or equipment falling onto the rooflight. This test is carried out with a 100mm diameter steel ball weighing 4.1kg, dropped from a height of 1.2m. The glass is allowed to break, but the impactor should not fall through.View video of stage 3 of the test - Hard Body Impact test
If the above tests do not break the outer pane, then it should be broken prior to proceeding to Test 4.
This is undertaken, as the glass could still break in a real situation.
4
A soft body test is undertaken on the inner pane of glass, as previously undertaken in Test stage 2.
The glass is allowed to break, but the impactor should not fall through.View video of Stage 4 of the test - Soft Body Impact Test.
5
A hard body test is undertaken on the inner pane of glass, as previously undertaken in Test stage 3.
The glass is allowed to break, but the impactor should not fall through.
6
This stage is only applicable to single glazed applications.
7
Any unbroken plies of glass should be broken. A static load weighing up to 180kg is applied to the glass, and left in position for 30 minutes. The actual weight is to be determined by the competent person overseeing the testing.
This test is to simulate the weight of a person (90kg) who has fallen onto the rooflight and become injured. Depending on the design of the rooflight, the weight of a second person (90kg) giving assistance should be allowed (180kg) total weight.
The 30 minute period is to allow for assistance to arrive to rescue the injured person.
8
Any glass fragments that have fallen during the testing are assessed.
The glass fragments should not exceed 50mm in any direction, and the total weight of al fragments should not exceed 50g.
9
Repeat the test sequence on any glass units still to be tested.
10
Repeat the test at different specified temperatures.
Compliance is achieved through a combination of upgraded outer and inner glass within a high performance fully thermally broken extruded aluminium framing system.