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I'm about to build a sturdy 7x10 shed. Planning to build it with suspended floor rather than concrete (for practical reasons and cost) and basing structure on 2x4 and 2x3 quality joist timber with 9 or 12mm external ply walls. Although this sounds expensive purpose built sheds are often weak, not durable and likely require a concrete base.  
It struck me that scaffolding poles would have strength, durabilty and possibly overall time advantages over a wood framework. A quick google tell me that inc delivery 12 10ft scaffolding poles  £187 and 12 2x4" 3m regularized, preserved timber £77 (not looked at cheaper/second hand materials or costed joining accessories). Choosing 12 of each just for discussion because that would be the basis of a stable cube. Obviously a lot of extra timber would be required in either case.
Major practical difficulties might be in joining square edged timber wall etc to the round scaffolding poles and to conceal them ( Mrs oldie wouldn't accept sticky out bits at scaffolding joints).
Any thoughts, please? I emphasize I wouldn't make a large, complex structure as the thought of being caught in collapsing scaffolding doesn't appeal.  
  

You could also consider uni-strut.

I'm about to use some of these to screw some ply to scaffold for mounting a fingerboard

https://www.scaffoldingsupplies.co.uk/products/details/3273.html

If you need to hide all of the scaffolding junctions then you will need to make the distance between outer walls and the scaffold uprights quite significant. For such a small shed this doesn't seem very practical, most of your internal space would be filled with metalwork!

As far as attaching a wooden skin to the scaffold goes, I can't even begin to think of a suitable solution, I've a feeling it would involve so much extra bracketry and secondary bracing that you'll end up buying a whole shed-worth of wood anyway...

As long as you put a good roof on it, there is no reason why a timber framed shed wouldn't last for decades. Keep it off the dirt and keep the rain out and it should outlast us all.

My shed is concrete foundations, blockwork dwarf wall, timber frame and OSB3 + tongue and groove timber cladding.  The money saved going to strand board over ply just about covered the timber cladding which looks pukka painted in black barn paint.  The up front cost is offset against the shed being likely to outlive me with minimal maintenance.

Scaffolding poles - how would you join the ply on etc?  If you start drilling it you’re going to put holes in the protective galvanised layer.  Having timber studs inside has been very useful because I can just screw on bits of timber for the distribution board, switches and sockets.  Light fittings just screw on, nails for pictures etc, all no problem.  It also leaves open the ability to trivially add insulation and plasterboard down the line.

I look forwards to some pro scaffolding post from people with more experience or imagination than me!

If you want to go down that road you could avoid having sticky-out bits, but keep the convenience of joining tubes with clamps by using 'Kee Klamp' or similar instead of pressed fittings.

Friend of mine built a pretty solid shed as a workshop by buying a good quality "normal" shed and lining it with plywood - pretty sure he put insulation behind the plywood for good measure.

2x4, even 2x3, timber would be overkill and heavy for a shed of that size, except, possibly, as a ridge pole, although depends what you want to use it for.

I personally wouldn't go down the scaffolding route for a shed, unless you're planning on taking it with you when you move house.

Sounds an appalling way to do it when you can by galvanised thin-wall rectangular profiles cheaper, they are made for the job.

Thanks.  I've been thinking I'd have to check out right angled section stuff first if if I seriously considered using tubular material. 

Thanks. I think that's mainly conduit type strength but I may well look at similar profiles.

You're right that self-building from scratch will be better and stronger than a ready-made one, assuming you use half-decent materials and that you design and construct it well. Yes, it will cost a bit more than buying off-the-shelf but these shed companies have economies of scale to buy materials and, as you say, aren't usually interested in producing something of high quality and with a long life.

As for using scaffolding poles to save a few quid, I'd agree with all on this thread who say keep it simple and don't make it harder than it needs to be and use wood for the whole job. As Dandan says, there's no reason why it shouldn't last for decades if well-designed and made.

On looking up these and similar fittings giving a nearly flush fitting with boards I see that there are possibilities if I did use galvanised tubes. In fact one firm offers multiple free cuts so using these and joining and angled fittings I could order a complete ready made framework if price was OK! 

I'll need to think carefully about all this though it does appear possible to avoid the "sticky out bits" and to attach ply etc with appropriate fixings (to might prove possible to back up these with timber offcuts and building adhesives for more strength and less expanse. As I've said I definitely need to look at square section material as well before deciding on timber vs metal frame.

youtube.com/watch?v=LP67MAoihZk&

He's a bit annoying, but it's a fine shed.

I'd watched that one, thanks. It was useful. I think he was building it over an underground bunker!

Apart from the lack of underfloor heating that’s my gold standard for a shed.  I skimped on money by going for OSB3 and asphalt roof shingles over ply and slate.  Oh, and I skipped the underground bunker part sadly.

If you wanted to expand, you could always dig down. Home wall?

Could always try cladding a market stall. Drill holes through bars to bolt timber cladding on. 

https://www.apexmarketstalls.co.uk/walk-in-stall?gclid=EAIaIQobChMI29XeuID9...

Just found a thread on the subject: Attaching timber to scaffolding shed frame ?

www.mig-welding.co.uk/forum/threads/attaching-timber-to-scaffolding-shed-frame.57947/

The ways of attaching timber seemed expensive or time consuming eg saddle clamps (possibly home made) or drilling large holes for the poles in timber studs.

When I built a shed of similar dimensions a couple of years ago I considered the scaffold idea.

It sounds like a good idea but it isn’t.

Building a wooden shed is far more labour intensive and costly than it would first appear.

Adding a scaffold structure would only add to the amount of labour involved and would present you with a whole set of new problems.

If it was a good idea then companies would be doing it - the fact that they’re not should tell you all you need to know.

Good luck with your build.

I once was a  scaffolder.  I'd certainly not use scaffolding at all.  Yes its strong and will never collapse even if its lost its galvanising.   A shed built out of scaffolding will need two braces.  Scaffold will flex and bend without braces.  Thats why you see diagonal braces on all scaffolding. These will go either outside the framework or inside.  That will destroy any notion of a flat surface to screw any timber on.   But you don't need scaffold for a shed.  Wood is used for sheds and buildings around the world because:-

Its light, long lasting (kept dry), extremely strong, flexible,  very easy to join using cheap nails or screws, or joints.  Easy to alter if you change your mind or make an error. 

Mass produced sheds are cheap & cheerful. .  Because they are generally made of cheap wood cut to the smallest possible dimensions - thats why they don't last as long as you may wish.

You've & others have already mentioned "special fittings", - extra work & money.Screws and nails are probably cheaper.

Concrete base is quite cheap.  Dumpy bag of sand will cost around £35 +plus a few bags of cement, but you could do away with that and use a suspended floor and the timber rested on pads or as one suggested, on  concrete block foundation.  The blocks cost on a pound or two each at the most.

It is also possible to make a shed in prefabricated form quite cheaply.  Make each side panel on the ground.  Cheap OSB on the inner side, a simple frame of timber around the perimiter and better timber/ply or whatever on the outer side.  That stood up won't move anywhere - its how many prefabricated wooden structures are made.  Erect the panels, screw or nail them together - and there's your shed.  No special fixings needed.

It will last for donkey's years if you keep the wood out of the damp and off the ground and make sure it has a good roof with plenty of over hang/guttering to keep the majority of water off the sides.

I would consider old scaffolding boards though.  These could be used as floor and/or walls or roof structure. Most scaffolding companies will sell off cheaply ones that have been declared unfit for safe use.  These will be perfect for sheds, unless you intend holding raves or whatever.

Scaffolding might be better than wood when you come to add that second floor extension

We’ve got stables which are timber built, and I think are about 70 years old. Timber frame with decent joints clad in 3/4 planks, and still solid after all this time. 

What am I missing, scaffold is at least 3x the price (after connectors are priced in) harder to work with and harder to fix cladding to than timber?

Most of the choices you need to make derive from what the shed is for, does it need to be secure against more than curious children, does it need to be draft-proof or just keep rain off, how will it be secured to the ground, how bad is the weather where you live...

jk

You're not missing anything of course. It does seem impossible to justify in terms of price and perhaps more important practicality. A really good quality wood shed commercially installed or in kit form might still prove more expensive however (haven't done the sums). One point: most sheds are not secured to the ground and many simply rest on the base and the weight of their contents is probably a major factor. 

I liked the theoretical idea of a strong  frame put together like Meccano where all the angles were automatically sorted but of course there would still be an awful lot of timber needed even it could be easily attached. As Jim Titt said it would be far better to use rectangular section metal if going down that route, but after a quick look at some used for warehouse shelving I don't think I'd go there either. I suppose that's why everyone makes wooden sheds! (some metal and plastic ones around but these seem to have many limitations in use and not necessarily outlast wood). 

You can easily secure the frame to the ground with metal strapping bars, or if using a concrete base you simply bed in several threaded rods, bolt them down through holes drilled through the framework at the bottom.  

We have a small summer house & a very cheap purchased shed.  Neither are secured to the ground and they've never moved.  And i live next to the coast.

Thanks for the detailed reply.

In fact my number one intention has always to been to prebuild sturdy panels. (I plan to build a suspended floor and use a couple of long concrete lintels, which I already have, as main support for this....I didn't want to muddy the waters about it in the discussion).

With perverse curiosity I suddenly thought of scaffold (or thinner poles) as they are strong and almost indestructible, but it's really obvious from replies that there is no way to render it practical.  Since the height would be only about 7ft I had wondered if one could get away without diagonal braces, and  just use 2 horizontals on each side (not at base) but from your reply this would be inadequate.

If you have a four sided structure made from ridged plywood.  It cannot, or should not flex - if you think about it the square or oblong material already has bracing built in.  Once four of these panels are joined together with a framework of 4" sq. or even less timber in each corner and screwed together they will all support each other.  If you are making panels insulate them between them, if you wanted you could use much cheaper OSB fo the inside, which will allow you to screw into it for shelves or whatever.  

Scaffolding or meccano is not solid that is why it needs bracing.

If you make the shed the same dimensions as the OSB or other panneled material such as marine ply (which is a bit expensive), you won't have to do much cutting and will have little if any waste.  these panels are normally  4ft X 8ft wide.    So to get a shed 8ft long and 6ft high at the eves you'd only need two whole sheets down each side and a third one cut down the middle - thats the side panels cut, and much the same at the ends and for the roof panels,  which most people cover with bitumen felt.

Thanks. Useful info. I had planned to have exterior ply running full height with vertical joins for best protection against water ingress, but now I'll probably use a good adhesive/sealer on horizontal joins at 4ft (the bottom 4ft will presumably get the bulk of the water anyway if the eaves are sufficient). I'll still need some vertical support on two sides as I want a 10ft shed. Our local timber merchant provides free board cutting which saves a bit of effort. No waste as offcuts will be used for shelves.

Scaffolding is a work platform not a building material. Although it may seem like a good idea believe me it isn't. I have built temporary fences using scaff boards and tubes, not to much of a problem as you can use board clamps to hold the boards to the tubes. Finding a way to fix boards to the inside and outside of scaff tubes to make a sealed building would be more trouble than it's worth. you would be better using structural steel which can have holes drilled in to it for attaching timber. Also scaff tubes are a bit more expensive than your google search would leave you to believe. For new tube you are looking at £1.50 per foot plus vat minimum. You might get used tube cheaper, but there is always the risk that if a scaffolding company is selling it then it is no longer fit for use. On the other hand you could get lucky, but you won't really save much money as anyone selling new or used scaffolding will know exactly what it's worth and how much someone is prepared to pay for it.