Want a year round workshop, need advice!!

[JimDiGritz]

Hi guys, I'd appreciate any input!

I want a 12m x 3m workshop in my garden which can be used comfortably all year round. I'm in the North of England so temp ranges from -5 to 28 with lots of wind and rain.

Situation:
Firstly I'm on a budget of around £5k for a phase 1 which needs to get me a weatherproof (non insulated) structure. Extra doors, windows and electricity can be phase 2. So whilst I want a permanent and quality solution I may have to this in stages.

I've only got basic DIY skills and haven't done this type of thing before.

There are already 3, 30+ year old concrete slabs covering 13m x 3.5m in place. They are in decent condition, but are stepped with 1-2 inches height difference. I don't know how thick the slabs are.

Option 1: Traditional brick build
Get the slabs smashed out and get concrete foundations poured for a brick building.
Pros: Permanent, quality solution.
Cons: £5k might just get me up to a concrete floor! Probably at least £15k total cost. Importantly it would probably be £10k before I had a weatherproof structure...

Option 2: Convert a shipping container
Pros: Cheap, (a used 40ft goes for £2k delivered) I'll have a weatherproof structure immediately. Would only need to resurface the slabs to a uniform level surface. 'Easy' to modify steel for window/door apertures at a later date.
Cons: After looking into this it seems I would need a crane would to put in place which would cost thousands!! Doh!

Option 3: Wooden workshop
Pros: Relatively cheap (6k?), Would only need to resurface the slabs to a uniform level surface.
Cons: would need building regs signoff due to size and it's proximity to the boundary. Can only fit wooden framed glazing since the wood will expand/contract??

Option 4: Metal workshop
Pros: Very cheap (£3k), Would only need to resurface the slabs to a uniform level surface. Can cut apertures and get glazing units or doors fitted easily at a later stage
Cons: Insulation would require stud, rock wool and ply lining... not sure about floor

Are these the only sensible options?

Have I missed any obvious pros or cons?

Thanks in advance

Jim

 

[footprints]

I would certainly avoid metal sheds or containers they will run with condensation, problems like that are very common on these types of forum.
I would go wood after all you will need planning anyway for a brick structure and it will look less "industrial".

 

[theprinceofdarkness]

If the weight of your new structure can be accomadated on joists then just flatten out the base(s) where they are. Lines of paving stones on mortar (?).
Having built a 12' X 8' shed sheathed in marine ply that had lasted for over 30 years without any degradation, I am convinced this is the way to go. The only problem is that it is very plain. If one put battens on it then clad it with some light weight wavy panel (from fence paneling), it could be made more rustic. I recommend that the framing is made from secondhand 4" X 2" Douglas fir floor joists, much stiffer then the metric stuff (38 X 68 mm). I say this on the basis of having moved from my old shed to a new one which has a different house in the garden. This is a conventional commercial shed 14mm shiplap wapped in with a nail gun. its a shame that when the wood warps it pulls the nails out. Like wise there are knots and splits which needed to be attended to.
The sheathing needs only to be waterproof and withstand the impact of a kids football., so studs at 2' I reckon 6mm ply would do, using 18mm chipboard for the inner skin, so you can put up brackets anywhere. And as much insulation as you can afford.
Frank

 

[chappers]

I would go down the wood route, a couple of years ago I put together a garage, supplied by these guys. I am a carpenter/builder but it was simple and I would say was within the realms of a DIYer, their instructions were clear and easy to follow, with loads of info on their website, we came up against a couple of issues and their customer service was excellent. The hardest bit was sorting all the bits into order, before construction began.

 

[theprinceofdarkness]

I disagree with Chappers, my son in law has a shed of similar construction. The problem as I see it is at least three fold, one is that the bottom timbers will always get soaked so have a limited life, the other is that, because the timber swells when wet the overall structure gets higher/lower depending on its moisture content, so you are told not to fix any vertical battens to the inside of the building, so this goes for things like the back of benches, unless you want it to rise and fall with the weather. The other problem is that when you have a door and a window in the same wall, the pieces of timber that run between them are not fixed, they just rely on the weight of the roof, so they drift from side to side. This has led to a corner going all wonky and the door not fitting at all well. This is because the door frame is a wooden channel that surrounds the walls but is not fixed to anything. A possible cure would be to have robust metal straps on the inside with slotted holes, so the walls can only move about vertically and the planks can not move horizontally.
Frank

 

[bernardgreen]

I would recommend using a post and beam construction with the posts on the slabs, as per the Walter Segal self build method. Cut the posts to length to suit the slabs rather then levelling out the slabs. A sheet of lead between the end of the post and the slab will seal the end grain. Sadolin or similar will protect the surface of the post.

https://www.selfbuild-central.co.uk/construction/main-structure/post-and-beam/

Many houses have been built using this form of construction. We built a very large one in 1981 and it is still in very good condition inspite of the site being flooded twice but not as high as the ground floor.

 

[angelboy]

What type of workshop? If you're planning on putting a load of big machines in there and then you really need to think about a solid concrete base.