Robina 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.

Findings & Recommendations In Robina Roof Condition Report

Flashing joints are not undersealed and have insufficient fasteners, non-compliant to SA HB39 refer 8.2 and 5.8.3 as shown. This will also reduce longevity as moisture from condensation gets trapped between the flashings leading to corrosion and future ingress.
Evidence of gaps present between flashings; this will also reduce longevity as moisture from condensation gets trapped between the flashings leading to corrosion and future ingress.
Due to the design of the barge cap and the height of fold down, it has raised the apron flashing out of position. This has creased the flashing and gaps are present, non-compliant to SA HB39 refer table 8.1.4 as shown. Also resulting from the barge cap being installed tightly against the roof sheets, if not rectified this could lead to scratches, corrosion, and future ingress.
Evidence of apron flashing being installed with the gutter in place, resulting in the apron flashing being notched around gutter brackets and gaps are present. Rectifying these issues will stop future ingress and will increase longevity.
Evidence of original fasteners holes present to the roof sheets, resulting from the ridge caps being reinstalled. Rectifying these issues will stop future ingress and will increase longevity.
Roof flashings and cappings need to be tightly notched (scribed)and cut to suit the profile of the sheet, as shown above in 8.2(b), it is important that this is done correctly as it prevents wind driven rain from entering the roof space and is a requirement for all roofs in QLD.
Numerous over tensioned and under fastened roof screws/split neoprene washers to roofs have been identified. If not rectified may lead to ingress, noncompliant to SA HB39 refer 4.4.2 as shown. Rectifying these issues will stop future ingress and will increase longevity.
Barge cappings have sharp edges pointing out, making it impractical for cleaning, non-compliant to SA HB 39 refer 5.6(f).
Flashing joints are not undersealed and have insufficient fasteners, non-compliant to SA HB39 refer 8.2 and 5.8.3 as shown. This will also reduce longevity as moisture from condensation gets trapped between the flashings leading to corrosion and future ingress.
All ridge capping connection joints are not undersealed and gaps between flashings are present, non-compliant to SA HB39 refer 8.2 and 5.8 as shown above. This will also reduce longevity as moisture from condensation gets trapped between the flashings leading to corrosion and future ingress.
Roof flashings and cappings need to be tightly notched (scribed)and cut to suit the profile of the sheet, as shown above in 8.2(b), it is important that this is done correctly as it prevents water and wind from entering the roof space and is a requirement for all roofs in QLD.
Ponding occurring on the roof transition flashings, non-compliant to AS 3500.3 refer 4.4.3, total drainage required of all roof components. Rectifying these issues will stop future ingress and will increase longevity.
Evidence of ridge cap flashings which have not achieved the 150mm of effective coverage, non-compliant to SA HB39 refer Table 8.1.4 as shown. Rectifying these issues will stop future ingress and will increase longevity.
Exposed copper piping and dissimilar metal water runoff is evident. If not rectified this will lead to possible failure of the roofing materials, and could lead to ingress. Copper piping needs to be taped/covered to prevent corrosion from occurring. Also, evidence of Dektites being sealed
with silicone and not fastened. Information about installation of Dektites are shown below.
Tray flashing has not been provided with 150mm of effective coverage, noncompliant to SA HB39 refer 8.1.4 as shown. Also, Dektite has not been sealed around the flue. Rectifying these issues will stop future ingress and will increase longevity.
Risk of aerial cable being cut by ridge flashings. Rectifying this issue will increase longevity.
Due to the barge cap being made too small to fit the profile of the sheets, it has raised the apron flashing out of position and water is flowing down the side of the property. Rectifying this issue will stop future ingress and will increase longevity.
Numerous over tensioned and under fastened roof screws/split neoprene washers to roofs have been identified across the whole of the roof, also fasteners installed on an angle and missing roof battens. Rectifying these issues will stop future ingress and will increase longevity. Non-compliant to SA HB39 refer 4.4.2 and 7.2 as shown.
The roof pitch is approximately 3.95-degrees as shown. The recommended pitch for this design of roof sheet is 5- degrees. Rectifying this issue will ensure the roof is compliant and increase
longevity.

Conculsion Outlined In Robina Roof Condition Report

There are many non-compliant issues as noted in this report and it would be beneficial to rectify these to ensure the roof is compliant and increase longevity.

Reference Images Used In Roof Condition Report

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Building Code References

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

4.4.2 Pierced-fastened Cladding

Fasteners in valleys or crests shall be tightened to compress flexible seals without deforming the cladding or damaging any washers.

Where nails are used, any local distortion shall not extend beyond the area covered by the washer and seal.

NOTES:

Compressed washers should be used to minimise water leakage and provide cladding performance as per design documentation.

Care is to be exercised to prevent the entrapment of swarf between the seal and the cladding for both crest and valley fasteners.

4.4.3 Corrosion due to crevices

Metal roof drainage systems and support systems shall be designed and installed to achieve
complete drainage or drying. Shielded areas capable of causing permanent ponding shall be
avoided to prevent the possibility of intense localised corrosion known as crevice corrosion.

NOTE: This type of attack results from contact of metal with moisture and slats under oxygen-deficient conditions in which trapped moisture cannot readily evaporate. It can be caused by lap joints, absorbent gaskets, holes, crevices under bolt or rivet heads, or surface deposits, including non-metallic materials such as elastomeric materials, plastics, fabrics, lifted paint films or accumulated solids.

8.2 Fastening

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
movements.

(b) Roof flashings and cappings to be tightly notched and fastened at the intervals given in Table 8.2(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.

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.