Are you prepared for the cyclone season?

Cyclone YasiNow is the time to secure your roof

There is an abundance of information about how to secure your roof and make sure the roofing screws you use comply with council codes.

Over the last 5 years particularly in north Queensland it has been taken very seriously.
After the impacts of both Larry and Yasi many reports were complied about the affect they both had on the building envelope for pre 80’s and post buildings.

These reports are readily available online for all to read.

What about your metal roof?

That brings us to the question, have you prepared your home or business for this years cyclone season?
Is your metal roof secure and in good order? Even though you may not have suffered any damage at the last event this doesn’t mean that your roof can withstand the next cyclone.
The cyclone season is only a few months away, officially starting 1st November to April a period of six months, so half of every year has the potential for a cyclonic event.
Do the roofing fasteners or cyclonic assemblies comply with local building codes?

Major insurance companies advise their policy holders to do the following…

Colours available in Storm-Tite

  • Check the condition of your roof regularly
  • Make sure that your home has been built to withstand a cyclone
  • Windows are secure and are fitted with shutters
  • Trim any trees or branches overhanging your house etc.
  • Repair any loose tiles, eaves or roof screws that might need repairing or replacing
  • If a metal roof has already been through a cyclone, the fasteners can exhibit weakening, consider replacing the roofing screws to ensure they won’t fail when the next cyclone hits

This is good advice to follow and also suggested by a report from James Cook University. Findings in a survey conducted are quite insightful and offer some practical advice for homeowner and business owners preparing for the next cyclone.

James Cook Report TR57

A limited survey was conducted by JCU during the recover period you can read the full report by accessing the link at the bottom of this page, this report brought out some good advice that we should all consider, a quick breakdown:

  • If you are repairing or conducting maintenance on your roof make sure you get the correct advice and technical expertise to do the job correctly.
  • Roof space inspections should be performed to detect any partial failure of batten to rafter connections. It is of paramount importance that these inspections be conducted on all buildings that have experienced high winds, whether damaged or not.
  • Installers should make sure screws penetrate both to the purlin or batten so their full load capacity can be achieve.
  • Buildings should be compliant with current Codes, Standards.
  •  Install roofing profiles and fasteners in accordance with manufacturer’s recommendations.
  • Use the right cyclonic assemblies or roofing screws for use with the given wind classification.

Another area that was extensively reported on was the windows and doors and how they performed during an event. It is a real concern that the locks and hinges on front doors may not be strong enough to withstand a cyclone. Food for thought, I encourage you to prepare your home or business, read the full report below for complete details.

Map of Australia Which is the most cyclone prone state?

In Australia the most cyclone prone area is Western Australia between Broome and Exmouth, however with Cyclone Larry and Yasi crossing the coastline in North Queensland, we can’t become complacent anymore about location.
If you do any research online about preparing for a cyclonic event, you will find mentioned many wind events like super thunderstorm cells and Hybrid cyclones that don’t fit into the main stream category system.

Cyclone Larry was a Category 4 bordering on Cat 5 in some readings, Yasi was a Category 5, both events caused catastrophic damaged to property, crops and the coastline.
Around 4.7 tropical cyclones per year have some impact on the Queensland coastline records tells us that since 1858 there have been 207 known impacts along the east coast.
Some of the regions involved

  • Cardwell
  • Brisbane
  • Tully
  • Bathurst Bay
  • Innisfail
  •  Althea
  • Mackay
  • Cairns
  •  Whitsunday Islands
  • Port Douglas
  • Rockhampton
  •  Mission Beach
  • Gold Coast
  • Southern Queensland
  •  Townsville

 

Category Wind definition table

Category Sustained Wind (km/h) Strongest Gust (km/h) Typical Effects
 1 Tropical Cyclone  63-88  Below 125 Damaging winds Negligible house damage. Damage to some crops, trees and caravans. Craft may drag moorings
 2 Tropical Cyclone 89-117  125 – 164  Destructive winds – Minor house damage. Significant damage to signs, trees and caravans. Heavy damage to some crops. Risk of power failure. Small craft may break moorings.
 3 Severe Tropical Cyclone  118-159  165-224  Very destructive winds- Some roof and structural damage. Some caravans destroyed. Power failures likely. (e.g. Winifred)
 4 Severe Tropical Cyclone  160-199  225-279  Significant roofing loss and structural damage. Many caravans destroyed and blown away. Dangerous airborne debris. Widespread power failures. (e.g. Tracy, Olivia)
 5 Severe Tropical Cyclone  Over 200  Over 280  Extremely dangerous with widespread destruction. (e.g. Vance)

Reference http://www.bom.gov.au/cyclone/faq/index.shtml (requires updating)

Check your roof and the roofing screws

Now is the time to prepare your property for the coming season, check the roof to make sure your fasteners are secure and don’t need replacing. The roof space should be inspected, and that no fixings have come adrift.
If your metal roofing has performed well during the last season, it is imperative you still check it for any loose fastening screws and replace them.

Storm-Tite tick all the boxes

Storm-Tite is a cyclonic roofing screw that has had an outstanding performance record and one that complies to all the codes, with it’s large domed washer that molds to the roofing profile it will give you peace of mind that water ingress will not be a problem through screw penetrates and you have a Cyclone Assembly that has been tested for a Category 5 event.

References – Check out JCU Report

Excerpt from Tech Report No 57 (www.jcu.edu.au/cts/publications/technical-reports)

3.2.1.4 Options for improvement

Some of the repairs inspected were made by the owners, and some by registered builders. Data from discussions with owners and neighbours indicated that owner repairers had lower success rates than registered builders. This indicates there may be a need for more information and training. A number of owners who repaired their own homes made reference to using their “mates” for help with the more technical aspects of the job. Where the “mates” were well versed in the requirements for buildings in this area, they became part of the information path.

3.2.2.4 Options for improvement

Roof space inspections should be undertaken to detect partial failure of batten to rafter connections. These inspections should be performed on all buildings that have experienced high winds even if they appear to be undamaged.

3.2.2.4 Options for improvement

The main reasons for the failure of the Pre-80s buildings at loads less than the current design load can be addressed by inspection, maintenance and upgrading of these buildings:

Roof space inspections should be undertaken to detect partial failure of batten to rafter connections. These inspections should be performed on all buildings that have experienced high winds even if they appear to be undamaged.

Where there has been deterioration of connections or members, this should be detected during the inspections. For example, whenever the roof cladding is removed (e.g. for replacement), the whole roof structure should be inspected and members or connections in which deterioration is found should be replaced.

3.2.6.4 Options for improvement

Failures of incorrectly installed roofing systems, indicates that there is a continuing need for education of installers and certifiers. For example, increasing the spacing of fasteners by 50% increases the tributary area of a single fixing by the same amount and reduces capacity by more than the factor of safety. Installers must be sure that all fasteners penetrate the purlin or batten properly so that they can be relied on for their full capacity.

3.2.8.1 Batten to rafter connections

Nailed batten to rafter connections have been identified as potential weak links in Pre-80s buildings in Section 3.2.2.2. In many of these cases it was clear that a failure had occurred as the roofing with battens attached had been separated from the rest of the building. However, Figure 3.43 shows a case in which the loads had started to lift the battens from the rafters (hidden damage). This connection would not be capable of providing its full capacity in another cyclonic wind event. It is only by conducting inspections inside the roof space that the extent of this type of failure can be determined.

Tech Report No 57 check out the full report at this link (www.jcu.edu.au/cts/publications/technical-reports)

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