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Tricks used by some shed companies



How to
shed quotes















Shed supplier tricks & tips


Open Bays - An Open Bay is a shed wall that is left un-sheeted. This is a popular option for rural sheds as it provides easy, and economical access to a partially enclosed area for tractors/hay etc.


What to watch out for - Make sure that you can face the sheds Open Bays into any direction. believe it or not, some companies have their sheds engineered or designed so that the Open Bay or Bays can only be faced towards the leeward of the prevailing wind. Sometimes they can be referred to as the dominent openings in the fine print.


What does this mean? - It means that the entire shed is likely to be weaker than one designed to face all of the cardinal wind directions. It's a an engineering trick or loophole that brings their shed up to the same wind rating as others while supplying less steel. It may have the same wind rating on it as a competitors quote (provided you face it away from the prevailing wind), it may  get approved by council etc but its actually be a weaker shed that could potentially blow apart if not positioned in the correct orientation or if the wind ever changes direction.


What to do about it? - "Can the dominent openings of the shed be faced into the prevailing wind?" is a good question to ask any shed supplier. Get them to put the answer in writing for you to make sure. Ask them if they are a registered member of the Australian Steel Institute (ASI), this is a voluntary body that more reputable shed companies can sign up to, it's cheap to join, ensures minimum standards are applied - there's really no reason not to be a member. The ASI has many reputable members and you should prefer to buy from one of those.


This shed has two (2) Open Bays and one (1) Closed Bay.



If high winds were to blow directly into the Open Bays of this shed it would not blow apart because it has been designed correctly. International Engineering Standards -

What to watch out for - Companies sprouting anything other that Australian standards. While the word international sounds impressive, the last time we looked, this is Australia and our building standards are better than most other countries.
What does this mean? - It may mean that they do not have the relevant certifications done for the buildings here in Australia. The sheds may be imported  and not Australian made
What to do about it? - Ensure that the buildings being considered for purchase comply with all Current Australian standards and is endorsed by the Australian Steen Institure.


Help if and when you need it.

Not all kit shed suppliers offer free help when your building your kit.

Many kit shed suppliers actually charge per minute or per question for technical assistance. It is advisable that you ensure that help is on hand and free when you need it from your supplier.
Some major kit shed suppliers are now sub-contracting building assistance out to a third party. This means that you, your concreter or builder can't even talk to the company who sold you the shed kit. Any questions have to be submitted via fax or e-mail with your credit card information and charged at $100 per question!


All we can say about this one is watch out!


Don't believe us? Below is one such example from an established shed manufacturer. P.S. You wont get this until after you've bought the shed!



" 2. The second and any other requests will be charged at $100. To take up this option, please complete the form overleaf, sign it and send it back via fax or email to the address on the form and a technical help advisor will contact you. "


Quoting Tricks:

Windows -

What to watch out for - Make sure that your shed or garage quote actually includes the windows; Openings, jams & flashings does not actually mean that the windows are included. The quote may imply that there is some type of provision for windows which leads you to believe that they were included, after all that is what you asked for when you rang up, right? A single window can cost $200 or more so 4 windows in a shed may add $800+ to the quote depending on size and wind rating. Also, you should ensure that if the windows are included, that they are available in all Colorbond colours, some suppliers only have 3 or 4 standard colours available. The shed company should also provide an individual wind rating for the windows as they have their own set of standards for water penetration etc.

What does this mean? - It means you have to read your quoted very carefully to insure that all inclusions have been quoted upon.

What to do about it? - If you not sure just ring back and ask "are the windows included, are they wind rated  and if so are they available in my colours".


Delivery -

What to watch out for - Make sure that your shed or garage quote actually includes the delivery destination in the final price. Some quotes may say something like 'delivery to ............... if on standard route".

What does this mean? - It means you have to read your quote very carefully to insure that all inclusions have been quoted upon.

What to do about it? - If you are not sure then just go with a company who includes delivery of the shed.





Steel Thickness - BMT & TCT - 0.51?

What to watch out for - Some unscrupulous companies are misleading consumers about the thickness of the steel that they are quoting.
There are 2 guages of Blue-Scope Steel commonly used for roof and wall cladding on sheds in Australia.


These are:


0.35BMT = 0.40TCT

0.42BMT = 0.47TCT

Where BMT = Base Metal Thickness (the thickness in mm of the "raw" steel) and TCT = Total Coating Thickness (the thickness including galvanising but not colouring).

Either of the above is acceptable for comparitive purposes as long as the it is stated which measurement has been taken.

So whats happening?
Some companies are stating a TCT of 0.51mm on their quotes instead of 0.47TCT. Make no mistake that this is the same steel as comapanies who quote 0.47TCT or 0.42BMT!


The companies quoting 0.51mm TCT have allowed for fluctuating tolerences with scant disregard to industry standards (metricated imperial tolerences)or the Blue Scope Steel Technical Data (below). Some other companies also claim a "thicker" steel because it is imported and of a lower quality or strength and is made thicker to compensate for the softness or grade of the steel. Australian made steel sheeting  is 550MPA (Grade G550).


Blue-Scopes own website states: "0.42mm BMT is the same as 0.47mm TCT."



Blue-Scope Steel technical Bulletin TB-14


What does this mean? - If you are unsure its best to ask the company what the BASE METAL THICKNESS (BMT) of the steel is and what the MPA of the steel is.
What to do about it? - We suggest that you stay well clear of these types of businesses who attemp to decieve you.






peed that the Shed was quoted for. This should be clearly written in Meters Per Second. E.g. "Site Wind Speed is 51ms-1" A few metres per second makes a huge difference because the scale is exponential. RULE NO. 3 Ask Questions! If you're not sure about something, ring the shed company and just ask them. For example, your shed is $5000 dearer that XYZ Company, perhaps there is a good reason why? or Can you please change your quote for me so that it has the same inclusions as the other shed quotes that I have? Nothing should be too much trouble for a reputable dealer. The only dumb questions are the ones that you don't ask. RULE NO. 4 Look at the materials you are getting and try to compare them as best you can. A reputable supplier is happy to give you a "material specification" on your quoted shed. This is a list of materials that your shed is made out of. If you don't understand it just ask your salesperson to explain it to you. Or if you have a friend who knows about this stuff why not enlist their help before making your decision? Some less reputable shed suppliers will ask for a deposit before they tell you what your shed is to be made out of. This is because they know that their frame member sizes are lighter. At the end of the day you are buying thousands of dollars worth of steel so make sure you understand what you're buying. RULE NO. 5 If you're still not sure, someone else may have done the work for you! To help shed buyers get a properly designed shed, the Australian Steel Institute issues ShedSafe™ accreditation to suppliers that submit their engineering for scrutinizing by their panel of engineers. You are more likely to get a properly designed shed if you choose one from a ShedSafe™ accredited dealer. Many government bodies are now insisting on only using ShedSafe™ accredited suppliers. The experts at the Australian Steel Institute have already had a good look at the shed companies plans and said yay or nay to them so why not take advantage of the free service?



Help to Choose the right shed for your site.


When it comes to shed design, Australia is divided into four main Wind Regions based on the maximum wind speed expected during peak storm activity.


The four main wind regions existing in Australia are as follows.


Region A :

The most common wind region encompassing the vast majority of the southern region coastal areas and Australia's expansive inland areas.


Region B:

Mainly encompassing areas above 30° latitude and generally greater than 50 km from the coastline, but within 100 km of the coastline.


Region C:

Extends along the coastline, within a distance of 50 km from the coast, for regions above 25° latitude. Classified as a cyclonic region.


Region D:

Covering a smaller region that is only specific to the west coast of Australia between 25° and 20° latitude, within 50 km of the coastline. Classified as a cyclonic region. For more specific determination of wind regions reference should be made to AS1170.2, Figure 3.1.


The region associated with a particular building locality can be found from:

  1. The local Council for that area, or
  2. A structural engineer, building surveyor or certifier.

The following map shows the approximate location of the region boundaries. It should be taken only as a guide and the region verified by one of the above methods.




It is very important that all considerations of your particular building site are considered when choosing a shed. If your shed does not have the appropriate wind rating for your site it could become dangerous during a weather event. or if it is overdesigned, you end up throwing away good money that could have been spent elsewhere.


Your area of the Australian continent might well be a general wind rating as shown above, but your block may either be on the high, middle or low end of that general wind rating, depending on local topographical influences and then your actual site might may or may not be shielded from surrounding buildings and hills. The point is, that there are more localised influences to consider and if you don't take these into account you may over-design your shed you end up paying more than you have to and if you underdesign it its not going to last very long.


Here is a good example: This shed has to be stronger at the top of the hill than it does at the bottom. The boffins at the Australian Steel Institute (ASI) and James Cook University have done tests which prove it.





Here's another good example: The shed in between the houses is not going to have to be as strong as the one in the paddock because the winds or storms will hit the houses to either side and deflect over the top of the shed, its a bit like aerodynamics with a car or plane.





So what does this mean to you? The council will tell you what you need, right? Well, not always, They may tell you something like W41 or N3 or N2 which is a general rating that we spoke about at the start, and is more appropriate to houses than to shed (structural steel) design. Some councils are quite good and are up to date with the latest standards while others, sadly are not. The latter seem to pass just about anything as long as it has a general wind rating on it which won't help you when your shed ends up in the lounge room during a storm and your shed contents are ruined and the insurance company won't pay out. It can only takes a gust, or a  short blast of wind to blow something apart and it can come without any warning.


So what can you do about it? For a start, you should stay clear of any shed company who only gives you a quote with a "N" or a "W" value on it. The values are now out of date so it means nothing. That's what we at Dinky Di call old school. The design and therefore the written quotation must list the Terrain and Topography value used that we mentioned above, as well as the Shielding and Importance Value. All of those things go into a mathematical enginering calculation that produces the correctly designed shed for you. A good company will be happy to help you with these considerations and also provide a full set of individual calculations to prove how they arrived at the engineering outcome for your shed.


E.g. Determine site wind speed:



Make sure that you tell your salesperson about your building site and how exposed or shielded it is from the general elements. If the companies salesperson does not care about that, or supply those details on the quote then you should probably  not consider that one for purchase.

Below is some literature released by the Australian Steel Institute regarding proper shed design.

Further information can be found on the ASI website at

How to  choose the right shed for your site

Wind Speeds for Steel Sheds & Garages

ASI Wind Action
Design Guide




Roller Door Installation Video

Residential Roller Door
Installation Guide

(generally less than 3.0m height)



For More Information visit

Industrial Series 2 Roller Door
Installation Guide

(generally greater than 3.0m height)



For More Information visit

Eltrak Sliding Doors General Assembly
*Please note that a comprehensive manual is supplied with your shed.



Steel Sliding doors can offer many advantages over traditional roller doors including:
Full Door Height Openings, Unlimited Door Opening Width,  Unlimited Cladding & Infill Options, Easy On-site Repairs, Add a Window or P.A. Door, Open Only as Wide as You Need. No Centre Mullions.


For More Information visit



Sand/Rock, good for foundations, however problems may be encountered wth site excavation and trenched  etc.



Stable site - generally the lightest footing design is applicable.



Moderatley Reactive. The majority of clay sites fall into this category.



Highly reactive clay sites requiring heavier than normal footing designs. Most "Black Soil" areas are at least a "H" class soil.



Extremely Reactive clay sites. These are not common, however results in very expensive  footings.


Problem Site. This may be Mine Subsidence, uncontrolled or controlled fill greater than 400mm in depth, landslips, or soft bearings/collapsing soils and trees near the construction  area.



A  sub-classification had been introdiced to indicate deep seated movement. The sub-classification is required for reactive sites, classes M, H and E and is symbolised by the addition of D. The full classification for these areas would simply be M-D, H-E or E-D.



Are you shopping around for a shed? does it need to be rated for a Cyclone region? You will probably have noticed the big price difference between the Reg. A sheds you see in shiny adverts with smiling fellas splattered with a little grease and those wind-swept fields with photo-shopped sheds advertisements and the reality of the dollars you have just been quoted for cyclone region rated sheds. HUGE!


Why should I pay so much more for cyclone region sheds? This is a very common questions and the simple answer is this:

  • Properly designed and engineered cyclone rated sheds from ShedSafe accredited dealers have a lot more steel in them than region A or even B sheds and so you have a shed that for 360 days a year is way over rated and when you need it to be...rated for very strong winds.


To help illustrate the differences we ran two different buildings through our engineering and take a look the differences in specifications.


First up we look at a

  • 6 x 9 x 3 enclosed 3 bay shed with 3 roller doors in Region A ,
  • Terrain Category 3, Topography 1, Shielding 1. Importance level 1,
  • with a site wind-speed of 34m/s.
  • Typical usage, enclosed storage not near the home, well sheltered amongst existing substantial buildings.



and at the other end of the scale with the same shed for

  • Region C, Terrain Category 2,
  • same topography and shielding,
  • Importance level 2,
  • with a site wind-speed of 62.22m/s.
  • Typical Usage , exposed, domestic car garage near home.




In a nutshell Looking at the table we see that the structural steel goes way up, as a guide the weight of the steel in the kit goes up by about 600 kg and on top of that there's 18kg more fasteners in the kit. That's an overall increase of structural weight and thicker wall cladding of 50%.


BIG SHED? Let's have a look at what happens when we make the Shed four times bigger and pull the front wall off it making it into a Open Front Farm shed 12 x 24 x 4.2 with 6m bays.


First up shed is a 24m x 12m span with 4.2m walls, open front farm shed 4 bays

  • Region A, terrain Category 2. (Open exposed farm land)
  • Sheilding and Topography :1,
  • Importance level 1 (Isolated Farm shed)
  • Site wind speed 37.3m/s



Then we place the same shed in Region C, a 24m x 12m x 4.2m open front 4 bay farm shed.

  • Region C, terrain Category 2. (Open exposed farm land)
  • Sheilding and Topography :1,
  • Importance level 1 (Isolated Farm shed)
  • Site wind speed 60.16m/s




In a Nutshell we find that there is over 3000kg more steel and an extra 60 kg of fasteners in the Region C. farm shed. That's over a 50% increase in Structural material and Fasteners when compared to the Region A shed.


What's this mean in layman terms? If your offered a cheap shed for Region C or D then watch out. It's likely to be under designed using engineering for the wrong district or old engineering that would'nt pass a decent inspection today using new guidelines produced after Cyclone Larry and proven by Cyclone Yasi. If you want to give your investment the best chance of standing after the next "big one" then expect to make a sound investment decision shed that will cost a bit more but be worth it in the long run.

Would you like a quote for a shed to go into Region C or D?

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Dinky Di Sheds Pty Ltd

Trading as Dinky Di Sheds

ABN 75 164 746 639


1800 785 224

Head office 226 Campbell St

Toowoomba 4350


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