St Lucia 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 as well as any relevant Manufacturer’s Instructions. The report will also strive to provide recommendations to extend roofs longevity.
Findings & Recommendations In St Lucia Roof Condition Report
- Water ingress is event related due to the recent weather events. Bedroom and front entrance hallway have suffered water ingress resulting in damage to the internal ceiling and wall linings. This may be more extensive on the upper side of the ceiling.
- Evidence of numerous damaged, slipped roof tiles to the front valley, resulting from lack of tile clips being installed. Valley roof tiles have not been cut to leave 100mm to 150mm channels as per manufacturer’s instructions, if not rectified may lead to ingress. Information regarding installation of roof tile valley is shown below.
- Evidence of heavy debris build-up to roof valley blocking water flow, roof valley is showing signs of deterioration and is heavily corroded. This should be removed and replaced with new as soon as practically possible to prevent corrosion and further water ingress.
- Evidence of heavy debris build-up to eaves gutters blocking water flow, if not rectified this will lead to water ingress and corrosion. Also the bottom row of tiles have been cut roughly which in some areas has made the overhang less than the manufacturer’s instructions.
- Evidence of previous repairs to the broken roof tiles in the valley using silicone which has no longevity and breaks down under the sun’s UV rays. Silicone to the broken roof tiles is just a temporary repair and should be replaced as soon as practically possible to increase longevity.
- Evidence of numerous slipped, damaged roof tiles to the valley, resulting from lack of tile clips being installed. Valley roof tiles have not been cut to leave 100mm to 150mm channels as per manufacturer’s instructions.
- Debris build-up under the roof tiles and valley, blocking water flow, if not rectified this will lead to ingress. Information regarding installation of roof tile valley is shown above.
- Evidence of inadequate, non-professional tile repairs using silicone and waterproof membrane, this is likely to trap in water and lead to further ingress, this is just a temporary repair and should be replaced as soon as practically possible to increase longevity.
- Evidence of lead Dektites showing signs of deterioration and have not achieved the 150mm recommended coverage. Also, evidence of drop tiles producing gaps. Non-compliant to SA HB39 refer to 8.1.4, as shown below. If not rectified this will lead to future ingress.
- Debris build-up in water courses potentially blocking water flow and may lead to ingress.
- Excessive gaps between tiles and tiles out of position, although common with this design in extreme weather events, could lead to ingress. Evidence of heavy debris build-up to eaves gutter blocking water flow to the rear of the property, if not rectified this will lead to water ingress and corrosion. Also the bottom row of tiles have been cut roughly which in some areas has made the overhang less than the manufacturer’s instructions.
- Evidence that ridge caps and mortar throughout the property are in good condition; however, weep holes are not present, non-compliant to NCC refer 3.4 as shown.
- No evidence of tie-downs inside roof space.
- There is no evidence of sarking present, and the pitch of the main roof is approximately 30.95 degrees, as shown. The minimum roof pitch for this design of tile is 20-degree without sarking and 15- degree with sarking.
Conculsion Outlined In St Lucia Roof Condition Report
Water ingress was most likely caused by lack of maintenance, repairs and faults as highlighted in this report. These issues have been aggravated by extreme recent weather events. It would be beneficial to have these issues rectified to increase longevity.
Reference Images Used In Roof Condition Report
Building Code References
3.4 Bedding And Pointing
Bedding and pointing that is used to hold down, align, weatherproof, infill and decorate the verge, eaves and junction and accessories shall be in accordance with this Clause.
- Ridge tiles and fittings may be laid without bedding or pointing provided they can be adequately installed by other means.
- Bedding and pointing applied to horizontal ridge tiles should include the formation of weep holes to permit drainage.
- Structural movement may result in the cracking of bedding and pointing
Mix proportions for mortar mixes used for bedding or pointing shall be as follows:
Cement mortar for bedding (1:4) 1 cement, 4 ±0.4 san minimum by volume
Cement mortar for pointing (1:3) 1 cement, 3 ±0.3 sand minimum by volume
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.