Canterbury Bankstown Roof Inspection Report Purpose:
Provide a roof condition report to N.C.C 2016 Vol.2, AS 1562.1, AS 1562.3, SA HB 39 2015: The installation Code for Metal Roofing and Walling and Manufacturer’s Instructions. Provide recommendations to extend longevity.
Inspection Site Gallery
Findings & Recommendations In Canterbury Bankstown Roof Inspection Report
- Tile bedding has been used to stop ingress around the back side of the chimney area. It is flat and prone to ponding. Below is a diagram from the manufacturer of a proven way to make the chimney water tight.
- Damage from hail events is still present on the tile shown in image. Remedy required.
- A cracked ridge tile presents on the front corner of the main roof. It has been sealed but silicone has no longevity due to breaking down under the sun’s UV rays.
- It has been noted that the pitch on the main roof is below 15 degrees and is noncompliant to NCC 2016 188.8.131.52 (b) Appears to be untouched and likely not part of the scope of works.
- On the main house, gaps in the front of eaves gutters are present because the rivets exceed 40mm. This is non-compliant to SA HB 39 5.8.1 below.
- Screws have been missed on horse stables and are non-compliant to SA HB 39 7.2.
- It has been noted that screws on the horse stable have rusted on the tops already. This should be referred back to the manufacturer.
- Screws have not been installed in the top purlin of the horse stable. This is noncompliant to SA HB 39 7.2 above.
- No screws in purlin shown. Ridge cap on carport has screws missing both sides and is non-compliant to SA HB 39 7.2 above.
- Barge caps on carports have insufficient fasteners and are non-compliant to AS 1562.1 table 4.2 below.
- It has been noted that the bedding is broken and, in some spots, missing on barge ends of granny flat.
- A broken barge tile still presents on granny flat and has been sealed with silicone which has no longevity.
- Barge cap tile is missing on granny flat.
- A large dent on the Trimdek rib is present on the patio of the granny flat. Ponding and ingress likely here. Non-compliant to SA HB 39 B6 5.1.
- Roof connection of the patio and granny flat does not have a flashing and is solely reliant on the turn up of the sheet. Non-compliant to SA HB 39 refer 8.1.4.
- It has been noted that nails from battens have protruded through rafters and batten join has not been cut on a 45-degree angle for optimum fixing.
- It has been noted that the front of the gutter onto the patio roof of the granny flat has been cut to discharge water.
- Ridge cap join on the shed has not been under sealed, non-compliant to SA HB 39 5.8.3 below.
- Ridge cap screw on shed roof has not been tightened correctly and a gap in the lap of sheet now presents.
- Screws in the shed roof have been missed and are non-compliant to SA HB 39 refer 7.2 above.
- Barge caps on the shed are only screwed top and bottom and are non-compliant to AS 1562.1 table 4.2 below.
- Ridge cap pointing on the granny flat has no weep holes.
Building Code References In Canterbury Bankstown Roof Inspection Report
NCC 2016 184.108.40.206 (b)
Roof tiles on roofs with a pitch of not less than 15 degrees and not more than 35 degrees must be fixed in accordance with Figure 220.127.116.11
Soldered or silicone-sealed joints are to be flush and lapped 25mm in the direction of the fall, with one row of rivets or other approved type fastenings at spacings not exceeding 40mm. This applies to all joints in flashings, cappings, eaves, gutters, box gutters, soakers, penetrations and all general sheet metal joints in roof plumbing.
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.
AS 1562.1 – Table 4.2
Flashing Type: Flashing edge to material other than metal cladding (e.g. barge flashing edge fixed to concrete wall)
Non-cyclonic Wind Regions: At the same or less spacing as the fastener spacing on the other flashing surface (e.g. roof or wall cladding)
SA HB 39
B 6.5.1 Surface Damage
Badly damaged panels should be replaced and the manufacturer consulted for the best way to remove and replace the panels. Minor damage can often be repaired in situ.
B 6.5.2 Sheet Damage
A dent, split or puncture in the external skin should not be left untreated as it will accelerate corrosion and, in some insulated products, absorb water into the insulation core. On a roof, it is sometimes possible to repair by over-skinning with a matching profiled skin. All edges are to be sealed to prevent moisture getting between the two skins. On a wall, it is not usually possible to over-skin and in this instance replacement of panel is generally the preferred option. The panel manufacturer should be consulted as to the preferred option.
8.1.4 Sizes and Covers
The minimum cover over other materials and structures for roof flashings and cappings is given in Table 8.1.4 For jointing, see Clause 5.8
5.8.3 Fastening and sealing with sealants
Joins in aluminium/zinc, aluminium/zinc/magnesium alloy-coated steel, prepainted steel flashings and cappings are to be fastened at intervals not exceeding 40mm and silicone sealed with neutral cure silicone sealants.
Sealants are to be sandwiched between the laps of the joint to provide seal and to protect the silicone sealant from exposure to ultraviolet radiation.