Alderly 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 Alderly Roof Inspection
- No underseal or fasteners to the flashing join, non-compliant to SA HB 39 refer 5.8.3.
- Eaves guttering with severe ponding in several locations, this will reduce the longevity of the guttering and is noncompliant to AS 3500.3 refer 4.5.3.
- No eaves gutter installed in the location shown.
- Apron flashings not installed behind the wall or without a pressure flashing, not watertight and non-compliant to SA HB 39 refer 8.2.
- Sheet here has had an overlap hand cut very poorly, it is open to debris and moisture to get trapped limiting the performance of the sheeting. Also note the large distance of 1100mm battens spacing.
- Roof battens have not been installed to manufacturer’s installation instructions, 90% of the battens have been installed at 1100mm centres where it is required at 900mm. Potential for loss of roof during an extreme weather event.
- Roof needs to be re-battened at 900mm centres as per manufacturer’s installation instructions.
- Gable roll to ridge capping transitions are heavily reliant on silicone which has no longevity due to breaking down under the suns UV rays, ingress likely in these areas. Dektite installation is non-compliant to SA HB 39 refer 5.8.3, no underseal and insufficient fasteners installed, also note the dektite straddles both the ridge capping and roof sheeting which poses potential for ingress as a positive seal cannot be obtained. No vent cap.
- Apron flashings incomplete, also note that there is likely old, galvanised or lead flashings still left on the roof and dissimilar metal contact can occur reducing the lifespan of the sheeting.
- Ridge capping joins not undersealed and with insufficient fasteners, non-compliant to SA HB 39 refer 5.8.3
- Screws missing to the ridge capping in location shown with potential for ingress through the screw holes.
- AC water condensed water outlet running directly into the eaves gutter will drastically reduce the lifespan of the gutter due to copper saturated water runoff, non-compliant to AS 3500.3 refer 4.4.2.
- No fasteners or underseal to gutter Join as shown in images, non-compliant to SA HB 39 refer
5.8.3. Also note the front entry gutter join has limited fasteners.
- Sheet pans not turned up(weathered) on the extension roofs as per manufacturer’s installation instructions, with ingress likely during wind driven rain events.
- It was also noted that these extension roofs were right on the pitch limit for the sheet profile, this will not likely affect the performance of the roof but should be monitored for potential ingress during extreme rain events.
- Ceiling space is quite hard to navigate around but it was evident several roof screws had missed battens in the small location I inspected, and it was noted during the roof inspection several areas where missing battens being loose under foot traffic. Non-compliant to SA HB 39 refer 7.2.
Building & Installation Code References from Alderly roof inspection report:
5.8.3 Fastening and sealing with sealants
Joints in aluminium/ zinc, aluminium/zinc/magnesium alloy-coated steel, prepainted steel flashings and cappings are to be fastened at intervals not exceeding 40 mm and silicone sealed with neutral cure silicone sealants.
Sealants are to be sandwiched between the laps of the joint to provide a positive seal and to protect the silicone sealant from exposure to ultraviolet radiation.
4.5.3 Eaves gutters
Eaves gutters shall be installed as follows:
(a) Gradients Deviations from nominal gradients shall be smooth and not cause
Where a building is likely to move due to reactive soils, gradients may need to be not flatter than-
(a) I :250 to achieve an effective gradient not flatter than I :500; or
(b) I :500 to achieve an effective gradient with no permanent ponding.
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.
Roof flashings and cappings are to be fastened as given in Table 8.2(A) and the following:
(a) Roof flashings and cappings to be fastened to withstand wind pressures and thermal
(b) Roof flashings and cappings to be tightly notched and fastened at the intervals given
in Table 8.2(8).
(c) Intersections, laps and mitres are to be fastened and sealed as per Clause 5.8.
(d) Joints in flashings and cappings other than straight joints to be accurately mitred,
fastened and sea led.
(e) Joints in flashings and cappings to be 25 mm and fastened at intervals not exceeding 40 mm. Joints are to lap in the direction of fall.
(f) All joints are to be watertight on completion of the installations.
4.4.2 Corrosion due to drainage
Metal roof drainage system components shall be designed and installed to prevent corrosion, erosion, or both, due to drainage from metal and non-metal roof drainage system components and, where applicable, cladding.
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.