COP v3.0:testing; specific-methods-testing-sheet-roof-and-wall-cladding

17.6 Specific Methods Of Testing Sheet Roof And Wall Cladding 

METHOD: RESISTANCE TO POINT (CONCENTRATED) LOADS

1. SCOPE

This Section sets out a test method for determining the resistance of sheet roof and wall cladding to point (concentrated) loads.

2. REFERENCED DOCUMENTS

The following documents are referred to in this part:
  • AS/NZS 1170 Minimum design loads on structures.
  • AS/NZS 1170.1 Part 1: Dead and live loads and load combinations.
  • AS 4040.1 Resistance to Concentrated Loads

3. SUPPORTING STRUCTURE

The supporting structure must be as specified in 17.3 General Methods Of Testing Sheet Roof And Wall Cladding.

4. LOADING SYSTEM

Concentrated load:

  • Concentrated load must be applied in a direction normal to the roof through a circular loading pad of rubber or similar material 100 ±2 mm diameter and 50 ±2 mm in thickness. The loading pad must have a Shore durometer hardness of 30 ±3.
  • The force must be transmitted to the rubber pad through a disc of steel, 100 ±2 mm in diameter and not less than 10 mm in thickness.
  • Where the dimension of the sheeting profile does not allow the use of a 100 ±2 mm diameter pad the shape must be spread over two ribs and not >0.01m² in area nor exceeding 200 mm in length.

NOTE: The 50 mm thickness of rubber may be made up of an appropriate number of layers 10 mm or greater thickness.

Measuring devices:
Deflections must be determined by means of a device capable of measuring to an accuracy of within ±0.05 mm. Pressures or loads must be determined to an accuracy of within ±2%.

5. TEST SPECIMEN

The test specimen must be as specified in 17.3 General Methods Of Testing Sheet Roof And Wall Cladding.

6. PROCEDURE

  1. Loads
    The loads and Variability factors must be those contained in 17.1.1A Variability Factors.
    To determine design loads (target load) for test purposes, the concentrated loads must be those contained in 17.1.2 Resistance to point load. The position of the test load must be determined by the type of test as prescribed in 17.3 General Methods Of Testing Sheet Roof And Wall Cladding.
    The target load must be increased by the variability factor determined by the number of tests according to 17.1.1A Variability Factors.
  2. A preload of 50% of the calculated maximum load must be applied for a period of 1 minute, before removing the load and zeroing the displacement transducer.
  3. A preload of 50% of the calculated maximum load must be applied for a period of 1 minute, before removing the load and zeroing the displacement transducer.

Measurements during serviceability tests.

Displacements of the test panel must be measured at a point on the specimen as close as practical to the load application.

If failure from buckling or other load discontinuity is evident prior to reaching the required load, the maximum force at failure must be recorded.

After not more than 1 minute following the removal of the load the residual displacement of the test panel adjacent to the load application pad must be recorded.

Strength limit state.

The part of the cladding furthest removed from the substructure and from the supporting members must be subjected to the specified concentrated load for a period of not less than 1 minute, applied to those parts of the cladding which will produce maximum deflection and maximum permanent deformation.

The behaviour of cladding, fastenings, supporting members and substructure must be observed and recorded. The maximum load is that which can be sustained irrespective of any permanent deformation.

7. REPORT

The following information must be supplied in the report:>
  1. The number of the report and the name of the client.
  2. The date and location of the test.
  3. The name of the testing officer.
  4. The type of test — Serviceability/ Ultimate.
  5. The test Procedure -reference to this section of the Code of Practice.
  6. Details of the material under test — Type/Profile/ Material/ thickness/ Spans.
  7. Substructure.
  8. Fastener type and fixing pattern.
  9. Mode and point of failure — Permanent deformation at fastener, mid span buckling.
  10. Deflection under maximum serviceability load.
  11. Residual deflection.