Building a Home Workshop, Part 1

However much you enjoy working on cars (or even just working with your hands), if you have no facilities in which to do it, life is hard. Sure in a mild climate - like that existing is most parts of Australia - you can work under an open-sided carport; I’ve even seen people doing major jobs like engine swaps on the road outside their house. But for convenience, security, safety and weatherproofness, a decent workshop is a must.

For the last eight years, I’ve worked beneath my house (the house is elevated) in an open-sided, concrete floor area. There have been three major problems with this: there is little security from theft; in wet, windy conditions moisture blows right through the workshop; and the limited height makes things squeezy for storage. The floor area is also smaller than desirable. (In the mild climate of SE Queensland, the lack of heating and cooling haven’t been problems.)

So I’ve decided to bite the bullet and build a proper workshop.

Size, Shape and Construction

The first decisions that need to be made are size and materials.

Here in Australia, the cheapest workshops to have built are sheds made from galvanised sheet steel. Normally called ‘garages’, a typical one is a “double garage” – 6 x 6 metres with a wall height of 2.3 metres and a shallow pitched A-shaped roof. Because they are produced in large quantities, the pre-cut materials are cheap, the erection is straightforward and the cost of putting in a concrete slab floor is kept well under control. Council (or planning) approval will also normally cause no problems.

However, while - as the name suggests – it’s big enough to park two cars inside, a double garage is actually pretty small. For example, if you want to work on your car in your workshop, a double garage is the absolute minimum space you need. The car will fit in the middle (but might need some pretty good manoeuvring to get it there!) and then you can work around it. But if you have a workbench, some machine tools and plenty of storage shelving, things start to get tight.

Of course, if the 6 x 6 metre shed is going to house just your tools, storage shelves and workbench, things get lots better! If you live in a mild climate, you might consider a 6 x 6 metre garage fronted by an open-sided carport – or even a large paved or concreted area covered perhaps with shade cloth sails. There you have a safe place to put a car up on stands, pull out suspension, etc, while the garage is used to do fine work and operate bench tools like a drill press.

If you’re on a very tight budget for money or space, you can take the above approach but use a single garage for your bench and tools, with the car parked in front of the shed, again on a hard surface.

However, it’s a lot better to budget for a double “double garage” – in other words, a 12 x 6 metre shed. It sounds huge, but it lets you park a car in the shed, have plenty of space to work around it (including for panel work) and have space for a proper workbench, machine tools and storage shelves. For major work, like restoring a car, this size of workshop will make an enormous difference to how quickly jobs will be done – and how well they’ll be done. If the workshop also has to do duty at times for car storage, you’ll also be able to organise a shed of this size so that two cars can be parked at one end when work isn’t being done on a car.

Like a 6 x 6 metre shed, a 12 x 6 metre shed is a standard size and so is commonly available. The metalwork is likely to be a little less than double the price of a 6 x 6 metre shed but note that other major costs like the concrete floor and required earthworks will in fact still be double the 6 x 6 metre shed. A 12 x 6 typically has four doors arranged along one side, or two doors located at one end.

If you want to make the most of the available space, consider having a non-standard size shed erected. Some shed manufacturers and agents have computer software that allows them to quickly and cheaply design sheds to pretty well any width and length.

For example, I have decided I want a 14 x 6 metre shed – 2 metres longer than ‘standard’. That might sound a trivial change, but the extra length is sufficient to have, for example, a bench across the full rear wall of the shed – and have room to work in front of it! When you put it that way, the gain is obvious.

A wall height of 2.3 metres is standard – but again many shed suppliers will allow you to specify a higher wall.

A workshop with higher walls has some major advantages.

Foremost is the extra storage space that is created – even in a 6 x 6 metre shed (with one wall taken up by two roller doors), an extra metre in height gives you 18 square metres of extra wall storage space! Another advantage is that a higher shed allows you to install a hoist – however, a hoist is an extravagance for most people with home workshops. A shed with a high roof is more easily illuminated as very powerful industrial lights can be placed high up, spreading the light broadly and evenly. Finally, going higher does not increase the cost of the concrete floor and earthworks, and often has a minimal affect on the erection cost.

When specifying a shed also consider:

• Ventilation (eg rotating wind-driven ventilators, opening windows)

• Insulation (eg foil insulation placed under the roofing sheets during construction)

• Natural lighting (translucent roof panels, windows)

• Presence or otherwise of a personal access door

• Required wind rating for the location

Location

Many people will have few options for where a workshop of the desired size can be placed. But before getting too carried away with mental pictures of where it will be, talk to your local council (or relevant planning authority).

Aspects that may be dictated by the authority include the minimum distance the shed is from the road, from boundaries, and from existing dwellings. There may be pipes, cables or easements over which the shed cannot be placed. Your neighbours may have a right to object if it blocks their view or shades them. There may be maximum floor areas and wall heights, and the shed may need to be coloured.

You’ll want easy car access to the workshop – not only for working on a car but also so you can move goods into the shed and also have the floor concreted without requiring the service of an expensive concreting pump.

Almost certainly the area where the workshop is to be placed will require some earthmoving. At minimum the area should be cleared of grass and other vegetation; at maximum, major earthworks including retaining walls may need to be built.

My Workshop

• Earthworks

I live on a steeply sloping block, so the location of the shed was always going to be problematic. My initial location required no less than a 3-metre high retaining wall and plenty of fill. That didn’t worry me much – until I got my first quote for earthworks.

“The wall will need civil engineering,” said the earthworks man. “And I don’t see much change out of six grand [AUD$6000] ”.

Since the total budget for the workshop is $20,000, that had me gulping. So I mentally moved the shed forward six metres. This required installing a new driveway entrance and still-substantial earthworks. The bill was going to be similar.

I then radically revised the workshop’s provisional location. In the new location the required earthworks consisted of a cut and fill – that is, scooping out part of slope and building it up at the lower level to form a flat pad. Also required was a 20 metre long, 1 metre high retaining wall.

I then realised that in order that really good access could be gained (access that would allow a concrete truck to back in, and that would allow me to easily move my machinery into the workshop), I’d need to have the driveway widened. This involved laying a storm water pipe and then having compacted fill placed on top.

The total bill for earthworks was about $5000.

• Concrete

Unlike the last large shed I had built in another Australian state, it is normal practice in Queensland for the concrete slab to be poured first and then the shed built on top of it. That means that the concrete slab forms the full foundation for the shed. (It also means that the slab must be dimensionally accurate.)

On my site, with half the shed on fill, the slab needed piers cast into place to support the area of concrete that’s been built-up. These piers needed to go down to the natural soil level.

This all seems straightforward, but it is not. Firstly, the local council must approve the plans for both the shed and the concrete slab. These plans are provided by the shed seller, but – as I found out – the plans are predicated on the site being flat and level, and not having any built-up areas of soil fill. When asked what changes the shed vendor would make to the concrete plans to make the slab suitable for my location, the shed guy just shrugged and said: “I’m not a concrete engineer!”

So then I got concreters in to look at the site. They suggested that more piers be used than had been deemed necessary by the shed vendor, and that furthermore, the piers on two sides of the shed be linked by a long L-shaped concrete beam cast into place.

Quotes for this work varied from around $6000 - $7000; I settled on one at $6950 – knocked down to $6500.

• Shed

I then started chasing final quotes for a 14 x 6 x 3 metre shed, complete with two roller doors in one end, two translucent roof panels and two spinning ventilators. The walls were to be in Colourbond and the roof in natural galvanised finish. The quotes were for supply and errection.

I found the whole process an eye-opener – primarily because the quotes varied so much. At the bottom end was a quote for $10,800 and at the top end, one for $14,600! I got the quotes by simply dropping off a specifications list for the shed and then asking that each company email me.

As it happened, I was back in the area of the $14,600 vendor the next day and I decided to visit. I wandered in and asked in a completely neutral tone if he could show me the features of his shed that made it worth 35 per cent more than one of his opposition.

I actually thought he might be able to show me better quality construction, higher grade steel, etc – but instead he simply got out the quote and said: “Hmm, perhaps I made some mistakes!”

And he did find ‘mistakes’ – enough to immediately pull the quote down by nearly $3000! What a scam...

In the end I settled on the cheapest quote, asked for a few design changes (bolting the main beams, rather than tek screwing them, for example), got another $300 knocked off the price and agreed to buy it at $10,500, including errection. Note that this shed manufacturer uses the same Bluescope steel, meets the same legal requirements and has a similar warranty as the most expensive shed maker....

Conclusion

If you’ve been keeping count, you’ll have seen that the cost of earthworks and the concrete slab will make up about half the price of the whole construction. Even on ground requiring minimal earthworks, the slab would still form a significant part of the overall cost.

However, the more I thought about it, the more I realised the slab is really important. Not only will it have to support the tools, machines and benches in the workshop, it also has to be rigid and strong when vehicles are being jacked-up on it. It must also stay level and not sink as any soil compacts over time. Finally, one day I’d like to build a car in this workshop and that requires a smooth and level floor, providing a datum from which to take measurements.

Think of it like this – the slab provides the working surface and the rest of the shed just keeps out the weather!

Next: in detail - earthworks, concreting, materials delivery

Go here for the next in this series.

Interested in home workshop projects and techniques? You’re sure then to be interested in the Home Workshop Sourcebook, available now.

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