The Shed Health Test

Read Quotes Like An Expert

The Golden Rules for Buying a Shed
  1. Always get at least 3 Quotes. The more, the better.
  2. Only accept quotes that pass The ShedHealthTest.
  3. Make sure each question's answer is in writing within the Quote.
  4. Get an example of the documentation you will receive. Ignore Brands, Logos & Brochures. Comparing the documentation, compares the actual products. See what you are really buying before deciding.
Region & Wind Code
End Portal
Internal Portal
Lateral Bracing
Roof Cladding
Wall Cladding
There are only 3 reasons why a Brand won't answer these questions in writing
  1. They are not doing the required calculations, which means they should not be selling the product.
  2. They are doing the required calculations, but the results are not National Construction Code, Building Code of Australia or Australian Standards® compliant, which means they should not be selling the product.
  3. They are not providing the type of steel they are advertising, which means they should not be selling the product.
  • Engineering audits indicate that there are more than 550,000 unsafe, non-code compliant Sheds in Australia. Supplying less Steel or inferior Steel means more profit. Do not become another victim of corporate greed & deceptive marketing. Make sure you & your family are getting a safe Shed.
  • We understand the importance of price, but it cannot be at the sacrifice of your safety. Spans, Centers, Deflection & Bracing are all critical, legal requirements for every Shed sold in Australia. If the manufacturer does not give you the information required to complete this test, then their product is most likely not compliant with the Australian Construction Codes & Standards.
  • You do not need to be an engineer or a builder. If your Shed's roof feels unsafe, it probably is. If you have any safety concerns about a shed you have purchased, send the engineering & documentation to for a free review. Get some peace of mind.
  • Extreme weather events are becoming more common. A light weight cold-formed steel Shed needs the strength of Heat Treated, Carbon Dense High Tensile Steel.
  • Unfortunately, many national Brands swap out High Tensile Steel for Mild Steel. This is a dangerous practice. Regardless of the Brand name, insist that they quote the Steel Grade in writing for each Structural Member required in your Shed, namely the Columns, Rafters, Purlins & Girts.
  • A reputable manufacturer will not hesitate in giving you the Grade of the Steel being used in writing.
  • As a baseline rule, do not accept any cold-formed Steel less than G450. G450, G500 & G550 are High Tensile Grades defined by The Australian Standards®. G means Grade. The number is the strength, eg. 450 MPa or MegaPascals.
  • To verify the Steel's properties, span capacities & suitability for your shed. Reputable Steel Manufacturers publish certified & tested data for their Steel. This information is critical for the Structural Engineers certifying your Shed.
  • Your Shed's engineering is invalid if the Engineer has done their calculations on & certified BlueScope® G450 Steel, but the manufacturer has supplied Chinese Q235 Steel. 450 MPa is much stronger than 235 MPa. It is a common practice in Australia, and difficult to detect as the Steel looks identical.
  • One Shed Brand is famous for displaying BlueScope® Steel coil at the front of their Sydney factory, but rolling Q235 at the back. It is a dangerous practice. Be careful. Remember, Steel is a commodity. It is priced by the Kilo. Beware of cheap Brands & their unsafe Sheds.
  • Deflection is the sag or bend in the Steel. Calculated deflection means a Structural Engineer has verified the size, gauge & grade of the Steel to be used. If the deflection complies with the Standards, then the steel is strong enough for your Shed's span.
  • The Australian Standards® limit Deflection as excess deformation compromises the Structural Integrity of your Shed's Roof & Bracing. That is very bad.
  • Deflection must be calculated. Get it in writing.
  • Lateral Bracing is the exact amount of bracing required to keep your Shed upright.
  • The Australian Standards® stipulate how it is calculated. A Shed cannot be sold in Australia if it is not structurally braced for its design wind speed.
  • The forces required by the Standards are quite large. As an example, a typical 6 x 9 x 3 Region B1 Shed's lateral bracing must be able to withstand 14.1 kN. That is approximately 1410 kg.
  • The Roof bracing must exceed 100% of the force required for your Shed. The Front & Back Walls share the work, so each must provide bracing that exceeds 50% of the total force required.
  • The Cladding or Cladding Diaphragm does not provide sufficient lateral bracing as required by AS/NZS 1170.2.
  • Absolutely. Top Hat is light weight, easy to install & perfect for small bays.
  • The Top Hat's Deflection will show you whether the Steel is strong enough for your Shed design.
  • It is important to get the Top Hat's Deflection value for the largest bay in your Shed.
  • No. Every Shed sold in Australia must have these calculations done. Get the values in writing, regardless of Brand, marketing, reputation or promises.
  • If the Brand can't or won't give you the information required to complete The ShedHealthTest, find another Brand.
  • In fact, we strongly recommend that you get at least 3 quotes. Shop around & use this free test to see if you are getting a safe, legal Shed.
  • Cladding is extremely thin, so it must be extremely strong. G550 gives that Strength. Colorbond® is G550.
  • One of the tricks in the industry is to provide cheaper, thinner or weaker cladding.
  • 0.42 BMT is 0.42 mm Base Metal Thickness. Paint adds another 0.05 mm. 0.42 BMT = 0.47 TCT or Total Coated Thickness. 0.42 BMT G550 Cladding is suitable for your Shed.
  • Use the Colour Drop Down to match the colours carefully. Colorbond® colours have all been trademarked. Classic Cream® is G550 Colorbond. Smooth Cream is not.
  • Non-Colorbond® cladding is inferior & tends to fade. Australia's Code & Standards are Strong because our Weather is Harsh & Extreme. Buy wisely.

The authors of this website are experienced engineers. They don't sell sheds, but they do have a passion for safe and Standards compliant shed design.

The authors are at the pinnacle of Australian cold-formed structural steel design technology.

They write the code and software solutions that engineers, structural designers and builders rely on for cold-formed steel. The technology and its engineering has been independently audited and verified by two of the most reputable engineering firms in Australia.

David Nan is the lead engineer. David has specialised in cold-formed structural steel design since 2008.

Mark Coorey is the lead programmer. Mark is a full-stack software engineer who has been developing technology solutions since 1996.

If you need any more information, call Mark on+61 402 746 964

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The Shed Health Test is a free quiz designed to help novices read & understand shed quotes. If you don't like it, don't use it.

The formulas and our calculations have been audited by independent engineers and are correct to the best of our knowledge. If you don't like the results, don't use the site.

Engineering is site & design specific. Take your quote, design specifications & site address to an Independent Registered Structural Engineer.

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