Shed Cyclonic Regulations

Posted on : January 31, 2012

Shedeye Investigator – The Australian Story

Introduction

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 www.eng.jcu.edu.au/cts .

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?

Summary

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!

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Innovation Award Submission 2

Posted on : October 28, 2011

Corrugated – a New Revolution

Shed Roofing Profile Innovation Submission 2

This entry to the Shedeye Innovation Award is slightly different to the others entries regarding new products in many ways. This product involves the cladding of sheds, residential & commercial roofing and also is an innovation in the rollforming industry. This is not the site to explain the importance of this new release of a profile sheet and its implications to the roofing, heritage, architectural and other areas of the steel roofing and cladding industry. Almost a reinvention of an iconic corrugated iron from as early as 1829 to the present, this product actually provides a new release of an old product but with superior spanning capabilities being produced on a uniquely designed current rollforming line based in South Australia. The technology utilised and patented by Revolution Roofing will return the “common” corrugated iron roof sheeting back to a rounder, fuller, shapely and deeper profile based on the original 19th century Walker “Gospel Oak” profile.

Once again the supplier and innovator of this product has had a difficult time in choosing which of the three new TRUE OAK designs to enter in the Shedeye Innovation Awards?  Their choice was between three of these revolutionary new profiles, True Oak Mid, True Oak Deep and True Oak ‘5’ and details available on their website REVOLUTION ROOFING.

True Oak Corrugated

But of the three – True Oak Deep was selected because of its ability to be used in sheds as a 0.35BMT product as roofing as it is the only roofing rollformer that has span tables (not cyclonic) for this gauge of roofing.  With the same cover as everyone else, and still  at a cover of 762mm – it offers a product for the shed industry without change to the sheeting layout in regard to the cladding and roofing. The only adjustment will that have to be made is flashings (only minimal), as the depth of the rib is 21mm which is the very reason for the increased strength.  The features of True Oak Deep are 40% deeper and 40% stronger than standard corrugated with the ability to go down to 3 degree pitch in roof. The profile is much stronger underfoot than standard corrugated and less susceptible to denting by foot traffic.

Here are the Span Tables for True Oak Deep:

True Oak Deep Span Tables

The best explanation as to the details of this profile is best explained in the diagram below with the comparison of True Oak Deep and Standard Corrugated.

Comparison

That’s the technical stuff in brief – but a photo paints a thousand ribs or less and deeper!

To top this new innovation off, Revolution Roofing is offering a True Oak 20 Year Watertight Installation Guarantee. This back to back material, corrosion warranty is only available when the product is installed by a Revolution Roofing Licensed Contractor. Not only will this benefit shed suppliers, but also shed erectors once they become an approved Revolution Roofing Licensed Contractor and supplier. New roof photo of church here in SA.

 

True Oak being installed

 

Of all the aspects of this exciting design re-invention is probably the foresight of the founder (Mr. J. Easling) to undertake LCA of this product which is a first in the rollforming industry. This is now the only roofing profile to be under review for the GREEN TAG certification (by Ecospecifier) and will be available to all architects and engineers.  

The details for information from Revolution Roofing on this submission is available at www.revolutionroofing.com.au  

 

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Strange Shed – Balancing Barn?

Posted on : September 9, 2011

The shed/barn house is 100 feet long and only 50 feet of the base is on solid ground? There’s even a window in the floor to look down to the grassy area below.

Balancing Barn - Would you feel safe?

This is a holiday home that you can rent that is a few miles inland from the Suffolk Coast in the UK.  Some renters of the property worry if too many people go to the end it will tip! Maybe only a few too many meat pies for lunch could tip the scales of balance. You can rent this  “The Balancing Barn” (www.living-architecture.co.uk) that sleeps up to eight people and costs from £638 for a four-night midweek stay. The house was designed, built and owned by the not for profit group Living Architecture – whose co-founder designed this, Mr. Alain de Botton. Very different Alain.

Heres another view of the amazing Balancing Barn:

Strange Shed? For Rent

 They say as soon as you enter and walk across the threshold of the balancing point – you feel strangely in danger of it tipping! The floor window above the swing would also add to this.

Don’t think our portal frame sheds could delve into this magnitude of architecture?
 

 

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Shedeye reaches 100 Shed and Garage Designs

Posted on : January 15, 2011

We are really happy with the progress that this site is making and we are getting some extremely positive feedback with some great constructive criticism.

We are well ahead of our expected usage of this site; in fact we are quite surprised that anyone can find it! There have been some great, quite unique designs that have come out of the site already.

You will find two crazy designs nestled away in the site, created without my knowledge from my twin 6 year old boys. They found the site based on my conversations and proceeded to create their own designs. I only found out when they proudly insisted that I come and see them! Goes to show that it is child’s play to design a shed and request a quote, literally, using Shedeye.

Check out Caleb and Harrisons designs here :

Calebs Crazy Shed Design

Harrisons Crazy Shed Design

We are hoping for 2000 designs by June this year, once this is achieved this will make us the largest online steel shed and garage design and image library in the world.

Shed used as an Office

Double Garage with tool and workspace

Standard Double Car Garage

Single Caravan Garage

Thanks for using the site.  If you think of anything that could make it easier or more useful please let me know.  Over the next 2 months there are some exciting new features being introduced.

Russ Condick

Shedeye Founder.

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10 of 10 – Things You Must Know Before Buying A Shed or Garage!

Posted on : September 6, 2010

Remember That Shedeye Can Help You Design Your Shed

Save up to 2 hours in shed and garage research, and filling out quotes by using the innovative web tool, www.shedeye.com.au100% free, always.

Shedeye was designed to allow you to visualise your shed, making it as close as possible to reality.  It also saves you hours by taking out the hassle of trawling through numerous shed sites, individually replicating the details of the shed your required.  A great online resource for designing, getting quotes and comparing sheds and garages.

www.shedeye.com.au

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8 of 10 – Things You Must Know Before Buying A Shed or Garage!

Posted on : August 30, 2010

What Type Of Look Do You Want In Your Shed or Garage?

For custom built sheds there are over 500,000 different colour combinations using the standard Colorbound(TM) colours.  Combine the different materials and components and you have millions of unique configurations.

The number one biggest problem with new shed purchases is the colour selection, either incorrectly ordered, or incorrectly researched.  Choose wisely and triple check you are getting what you want as you’ll have to live with the colour once the shed arrives

The cladding you choose can be a standard corrugated (curved) surface, a square look or a combination of the both.

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