Narangba Roof Inspection Purpose:
Provide a roof condition report to AS 1562.1 AS 1562.3 And SA HB 39 2015 The Installation Code for Metal Roofing and Walling Provide recommendations to extend longevity.
Inspection Site Gallery
Findings & Recommendations Report For Narangba Roof Inspection
- Downpipe spreaders flowing onto flashings is non-compliant to SA HB 39 refer 5.7.7.
- Widespread swarf is evident across the lower roof areas, non-compliant to SA HB 39 refer 3.6.
- Minor ponding is occurring in several areas of the eaves guttering upper and lower roofs, non-compliant to AS 3500.3 refer 4.5.3.
- Screws missing to tray flashings in several areas, non-compliant to SA HB 39 refer 7.2.
- Valleys not turned down with potential for ingress from water drawback, noncompliant
to SA HB 39
- 2 Sheets in location shown have random screws installed, unknown reasons.
Building & Installation Code References from Narangba roof inspection report:
(d) No spreader is to discharge roof water onto or over ridge tiles, mortar joined tiles, flashings, timber fascia or a roof sheet side lap.
SA HB 3.6 Cleaning Up
Normal installation practices such as drilling and cutting usually leave offcuts and metallic swarf on or around the roof area. These materials and all other debris, including blind rivet shanks, nails and screws are to be cleaned from the roof area and gutter regularly during the installation process as unsightly staining of the surface due to oxidation of the metal particles will result, leading to corrosion and possible failure of the roofing material or futtering. Where practicable, the entire installation should be cleaned down with a blower vax, swept or, alternatively, if a water supply is available, hosed down at the completion of work.
AS 3500.3 4.5.3. Eaves Gutters
Eaves gutters shall be installed as follows:
Gradients: Deviations from nominal gradients shall be smooth and not cause permanent ponding.
1) Where a building is likely to move due to reactive soils, gradients may need to be not flatter than:
1:250 to achieve an effective gradient not flatter than 1:500; or
1:500 to achieve an effective gradient with no permanent ponding.
2) Light condensation will not generally cause permanent ponding, whereas heavy condensation, particularly in conjunction with retained silt, can reduce the design lifetime of the product.
SA HB 39 refer 7.2. Roof Sheet Span Information
The roof sheet support spacing for the various profiles are listed in the typical span information of the manufacturer’s product literature. This information varies depending on whether it is an end span, internal span or overhang.
The typical span charts are based on the ability of sheeting to withstand the wind loads specified in AS/NZS 1562.1 and the NCC. All sheeting is to be fixed to each and every roof support unless otherwise approved by a structural engineer.
SA HB 39 refer 5.4 Valley Gutters
(b) Valley head to be securely fastened at the ridge and turned up against the weather.