Shed Cyclonic Regulations

Posted on : January 31, 2012

Shedeye Investigator – The Australian Story


This discussion is broken into two points regarding LHL testing. The first is with a rollforming perspective, and the second from a shed manufacturing perspective.

The main aim is to generate discussion to educate and learn from the current regulations concerning LHL Standard Cyclic Test Method for Cyclonic Areas. It was officially phased in on the 30th April 2009 to meet the Building Code of Australia Specification B1.2.

Interpretation of Low-High-Low Cyclic (LHL) Testing

 Basically it is simulated wind conditions (cyclonic) method using low, the high, then low pressure sequence to test the wind loads on metal roof cladding in cyclonic conditions. This LHL test is considered better to represent typical cyclic regime on metal roof assemblies than the DABM test method that was in the Northern Territory and the Australian Standard AS4040.3:1999 test method previously used in Queensland and Western Australia. The test involves includes the roof assembly including the roof sheets, fasteners and the battens and their support fasteners.

From April 2009 all cladding and batten manufacturers need to demonstrate that their metal roofing assemblies specified for cyclonic areas of Australia have been tested using the LHL test method. More details are available in Technical Alert No 08/1 at .

Rollforming Manufacturer Perspective

So to understand the basic test of the roof assembly – each manufacturer must get their roof sheeting (all profiles specified for cyclonic regions) tested under LHL. There are numerous testing stations in Australia and the one chosen here for example only is the James Cook University Cyclone Testing Station. Also in this discussion the roof cladding type is corrugated – produced by all of the rollforming companies in Australia and also used in cyclonic regions in Australia. The LHL stipulates that for a company to sell corrugated roof sheets in cyclonic areas – it must undergo LHL cyclic testing. The BRAND corrugated roofing is sold by some of the big multinational rollformers throughout Australia. The Company here is Company ZZZ, and to comply it sends it corrugated roof sheeting to the cyclone testing centre to meet compliance to the LHL test. This sample is rollformed on one machine that converts the coil (flat sheet) to corrugated roof sheets. This is assembled with battens and fasteners then tested under LHL. Once the LHL tests have successfully completed Company ZZZ can then supply corrugated roof sheeting to all cyclone areas in Australia. Company ZZZ has numerous corrugated rollformers as well as the one that supplied the sheets for LHL testing and yet all the corrugated roof sheets are compliant to LHL.

By stipulating that the company brand of corrugated has to be LHL tested, they are accepting that all the corrugated rollformers held by that company are identical. For another company to provide corrugated roof sheets to cyclonic areas – they too have to complete LHL testing. This assumes that the profile and rollform machines are different from company to company. Those in the rollform industry know that this is not the case, and apart from some minor variations between machines it is the profile of corrugated (along with the feed coil properties) that determine the strength and its ability to undergo LHL test compliance. Yet Company XXX has to undergo LHL testing even though all its machines are identical to Company ZZZ machines. This is the only industry where identical products are testing not the manufacturing process.  The LHL testing should in fact be the responsibility of the rollform machine provider – and most of these (especially Australian and New Zealand machines) would all supply compliant corrugated roofing sheets. There should be compliance for these rollform machines to be registered to conform to LHL testing. Yet Company ZZZ who has gained LHL compliance for its rollform machines can buy a new corrugated rollformer from China that may not meet the standards previously obtained from its original sample material. It is the machine that makes the corrugated roof sheet and so testing of one machine from a multinational company will allow inferior product by the company utilising untested machines.

Shed Manufacturers Perspective

From a roll former’s point of view, if it can be demonstrated that structural roll formed products with the same girth and BMT thickness such as roof sheeting and top span that is identical in profile, and manufactured from the same coils of origin that have undergone the LHL testing criteria, what is the real purpose of having the product tested while there remains a question regarding the safety of the total structure? For example, the manufacturer of roll forming materials may argue that while the LHL testing applies only to the roof cladding and “immediate members” that support the roof cladding, failure to include the importance of the connections at the apex, knee, and tie downs, begs the question; how does the manufactured product miraculously become only when the supplier has had the immediate members tested in a wind tunnel that simulates cyclonic conditions?

It is in the real world where actual wind tunnels exist, moreover, regardless of whether the product has been endorsed by shedsafe, structures will continue to fail even before completion.  So concerned are the self appointed gatekeepers to the shed industry, they have aligned themselves with the BSA and other bodies in conducting seminars across the country, advising erectors how to construct sheds so as to avoid the structure  collapsing during construction.  Shed erectors are playing roulette at the hands of shedsafe’s smoking mirrors illusion, hence, the shed erector will be potentially at fault if it can be shown there was a failure on the erector’s part in failing to use his skills in making sure that the whole shed was acting as a diaphragm in order to hold it together in the event of a storm or freak wind that often collapses the frame during construction. In other words, wherever there is an accident on site during construction resulting in person(s) injured or killed, the shed erector, rather than those who endorsed the shedsafe product, will be liable.

Now for a comedic look at the situation.

 A recent inspection of a 3x3m garden shed is an example of the hypocrisy within the industry.

A Building inspector was recently surprised to notice that a garden shed structure was actually made from a .75 mm stud frame with 12mm tie downs at each stud, along with two extra 12mm tie down’s at each corner. He was further surprised to notice bracing on each wall and three 64mm top spans on the roof fastened with 12x 14×20 tek screws with 0.42BMT cladding properly secured to the top span, yet while he was surprised at the extent of the structure, given that most 3x3m garden sheds don’t have a frame at all, he nevertheless failed the inspection because the shed manufacturer had not stated on the plan that the cladding had a reference to the LHL testing.

When the customer advised the supplier, who in turn asked the building inspector to explain the problem, the building inspector advised the supplier to read the literature provided by the ASI’s shedsafe endorsement.  Interestingly, the booklet showed a reference to the LHL endorsement, but no reference to the safety of the entire structure.

Getting back to the manufacturer’s point of view, there is clear evidence that the only guarantee and endorsement of ShedSafe may offer is the customer will have no idea of the origin of the actual material used to manufacture the product or if the product has been tested.

Therefore if the structure is endorsed by an incompetent engineer who has compromised his or her ethical standards, nevertheless signs a FORM 15, there will be no recourse unless the company that has hired the engineer replaces the product. The replacement is usually conditional that the incident be kept confidential.

Besides this, as already pointed out, if one single LHL endorsement can be used as a blanket cover for an entire corporation regardless of the corporation’s many separate roll forming outlets with differing profiles, or whether the origin of the coil is Australian or Imported, how does the building inspector know the difference without authentic documentation? Does the material in question have a specific test certificate stating the origin of the material along with an endorsement from the testing facility given that what he is inspecting explicitly refers to the cladding and top span required on the approved plan, or does he really care about the weightier issues that he may be forced to confront?


The main reason of this viewpoint by two very different members of the shed industry supply chain is to generate discussion that will enable shed purchasers to be confident that all the factors & PROMISES made by the industry groups are capable of being produced in the supply & erection of their shed.

 To finalise, there is an instance of a well known shed supplier who sold (supply) only to a customer that collapsed during construction. This occurrence was exploited by others in the shed industry to their advantage by giving this as an example of a non-compliant shed industry member. Very far from the truth, the particular shed supplier warned the shed erector constantly regarding construction techniques – all advice was ignored. Subsequent investigations resulted in the shed manufacturer being involved – but of all the parties involved – the shed manufacturer supplied and erected the shed for no charge. This is the type of example of pride in this industry we need. The investigating bodies had no idea of what had occurred – only guesses.

Many thanks to the contributions of the rollformer and the shed manufacturer for this valuable insight into only two areas of the industry. Hopefully more to come from these two gurus of the industry!


8 Responses to “Shed Cyclonic Regulations”

  1. The Roofer said...

    Go for it!

    Another classic article!

  2. Dave said...

    ASI & Shedsafe are slowly passing away into the past. Their original idea (if they kept to the charter) was great until it became a marketing tool for the worshippers of ASI and its sponsors. Along with BlueScope, and it’s shocking management team – all of these groups will be a memory!

  3. John said...

    Wow! A mature industry with immature regulations, what a joke.

  4. The Roofer said...

    The industry is fine – but the fools that are running this new fail safe method of accreditation are the big worry – no answers, no response, no idea, because they are the mouthpiece of the ASI and its sponsors. I would recommend Fletchers (Stramit) get back to basics with this ASI group.

    Either that – or haul in the free marketing guff that ShedSafe is spreading around like a $2.00 milk promo!!!!!!!!!

  5. Phil NQ Sheds said...

    Was going to join, but what do they actually do?
    Guy came up and just wanted money for guaranteed sales
    told him where to go

  6. SHED ERECTION said...

    They been here as well in WA
    Not really value for money

    They said same thing! your sales will only grow with us Why i asked
    because of our marketing campaign on ShedSafe website.

    Didnt know what it was until they arrived here

  7. Paul CSB said...

    Guys, this is a one sided argument. I suggest you take a look at the flip side; at the all the things they are doing right in helping to guide our industry.
    They are training engineers and certifiers on how to design and assess buildings so they meet the code. They are trying to lift the standard by way of education within the industry, with a small budget. They may not get everything right, but they are heading in the right direction. I agree with you criticism of companies who use 0.35 BMT product as roofing, but holding this against ASI is not the way to fight it.
    You might be interested to know that Rio Tinto will not accept a quote from you if you are not Shed Safe Accredited, and some Qld insurance companies will only replace a shed with a “shed safe” shed. It is worth us being accredited just for the help and support we receive from The Shed Group.
    Paul McLoughlin
    Capital Steel Buildings

  8. The Roofer said...

    Hi Paul,
    While I agree in principle to your comments – the big factor is a statement that appears on your own website:
    “The Shed Manufacturer has assured their compliance.

    •This means that, the Shed Manufacturer has signed and submitted documentation confirming that all of their shed designs are in accordance with the Australian Steel Institute Design Guide Portal Frame Sheds and Garages (2009).

    WOW: What about ASA, BCA etc – it seems like a manufacturing body is dictating the design and engineering rules -too much power in some hands could be dangerous!

    A lot of the news and events on your website is also over 3 years old – there has been numerous new reports from the JCUNQ Cyclone testing facility, Australian Standards, BCA – so “ShedSafe” as a group or authority should be ensuring that all information (including websites) is kept up to date.

    What will happen if BlueScope (ASI main driver) fails over the next year? ASI and ShedSafe will become history and just be bought out for minimal dollars for the brand name alone!

    Hope Shedeye lets this comment through, as my industry is the steel cold rollforming and the shed industry is capable of self regulating without all these extra commercial bodies expressing themselves as authorities of the shed industry!

    Rio Tinto has obtained quotes, supply and materials for their sheds from China, independents from Darwin, India and even steel stud frame modules from New Zealand.

    “some Qld insurance companies will only replace a shed with a SHEDSAFE shed” – can you name one Queensland Insurance company that stipulates this?

    Sorry to be so negative Paul – but I feel ShedSafe is a good brand – but it should not dictate ASA and BCA standards – it should be implementing them. Look at the 0.35BMT quotes coming through from ShedSafe accredited suppliers going on roof areas!!!! Not Good!

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