Planning to make a 12x24ft workshop in my garden on blocks and seeking feedback on current plan

[Wernahoppa]

Hi,
This is my first post, I hope it's in the right place.
I want to make a 12x24ft workshop roughly based on Leo's from Hand-i-craft youtube channel.
Concrete blocks will support treated 6x2"s at 16" centres floor with celotex in and joins taped with alu tape and 18mm hardwood ply on top.
Walls will be 12mm ply, 3x2 or 4x2 studding with rockwool in, breathable membrane, batons thenbarn style feather edge cladding.
Pent roof at 5 degrees,made of 80mm insulated roofing panels, maybe with 75cm hangover at the front and 50 at the back.
I have bought upvc french doors and 4 windows already.

My first query is regarding the amount of blocks, spacing of blocks and the design of the floor.
I've drawn out my initial plan and attached it.
Are there enough blocks? Is using 6x2 overkill? Perhaps there's a better way to do it?

I look forward to hearing from you

 

[Jameshow]

I'd put in more blocks say 3 front to back and 5 side to side. Reducing spring in the floor

 

[__jvc26]

[Ed] Was a query about building regs application — may have misremembered!

 

[Wernahoppa]

24’x12’ won’t that require building regs?

Small, detached buildings less than or equal to 30m2​

These must be single storey – a roof mezzanine or loft floor would not be permitted, and:

• The internal floor area must not be greater than 30m2 (for example 3m x 10m, or 5m x 6m), and
• The building must be constructed substantially of non-combustible material unless it is 1m or more away from any boundary.

It will be futher than 1m from the boundary, and no taller than 2.5m.

 

[Wernahoppa]

I'd put in more blocks say 3 front to back and 5 side to side. Reducing spring in the floor

In my picture i've drawn 3 front to back and 4 side to side, which aligns with the 3 floor parts sitting on them where they join. If 5 blocks were used, I presume a different floor design would be called for?

 

[Housey210]

celotex, i take it in joist spacings. be wary if the underside is exposed, rodents will soon eat that.

 

[Jacob]

IMHO Rockwool not good in walls as it will sag slightly and leave cold bridges.
Needs to be solid Celotex, Kingspan, etc very well fitted tight between studs plus mastic/foam/tape sealing all gaps and joins.

 

[Mr Christopher]

Hi,
This is my first post, I hope it's in the right place.
I want to make a 12x24ft workshop roughly based on Leo's from Hand-i-craft youtube channel.
Concrete blocks will support treated 6x2"s at 16" centres floor with celotex in and joins taped with alu tape and 18mm hardwood ply on top.
Walls will be 12mm ply, 3x2 or 4x2 studding with rockwool in, breathable membrane, batons thenbarn style feather edge cladding.
Pent roof at 5 degrees,made of 80mm insulated roofing panels, maybe with 75cm hangover at the front and 50 at the back.
I have bought upvc french doors and 4 windows already.

My first query is regarding the amount of blocks, spacing of blocks and the design of the floor.
I've drawn out my initial plan and attached it.
Are there enough blocks? Is using 6x2 overkill? Perhaps there's a better way to do it?

I look forward to hearing from you

Consider pitching the roof at a greater angle. In my opinion it will look better, shed water better, give you a better feeling inside and greater scope within. Check planning though as I think anything more than 3m at the tallest would require planning, unless of course for some other reason it already does.

 

[AndyMc]

What are the concrete blocks standing on/in? Depending on the load and vibrations they're likely to subside. You should also think about the internal loading - do you have any heavy equipment going in?

 

[MikeJhn]

For the foundations of sheds I have used concrete fence posts instead of pad foundation, spreads the load on the ground better, the only need for DPC is to level the joists running across them.

For the walls, look up "Canadian rain wall"

 

[trvlr]

This company in Kent has a good range of sheds etc.; as do many others.. If you go their website and lookk for the "bases" link (top menu) you can see the various methods, including the concrete posts method:

https://www.kentleisurebuildings.co.uk/copy-of-garage-roof-refurbishment?lightbox=dataItem-jsd82m9k
Treated wooden supports are half the price of concrete - with 20yr life; concrete obviously a lot longer... The advantage of both post systems is that they allow to create a level base/foundation for the building.

At the least their illustrations may give you some idea of how/where to locate whichever posts?

 

[Recky33]

My shed's 12ft x12ft and stands on 12 pillars (3 rows of 4) it's been used for many things in the last 20+ years, at the moment it's carrying a half ton 12" Robinson planer and a one and a half ton Harrison lathe plus everything else life brings you over the years, Still solid as a rock

 

[2sheds]

I've used QuickJack spikes from Shed Base Kits - Plastic Shed Bases | Foundation Solutions.

Bit more expensive but work really well, you don't have to do any digging unless you'ver got a lot of height difference in the ground, andvery easy to fit and adjust.

You can also look at their standard designs and see how many spikes you need. If you decide on blocks, I guess you could just use a block everywhere they suggest using a spike, and add a block at every intersection in between?

https://shedbasekits.com/product/quickjack-kit-3m-x-4m-heavy-duty-log-cabin-or-garden-building-kit/
Cheers
Steve

 

[Housey210]

Hi,
This is my first post, I hope it's in the right place.
I want to make a 12x24ft workshop roughly based on Leo's from Hand-i-craft youtube channel.
Concrete blocks will support treated 6x2"s at 16" centres floor with celotex in and joins taped with alu tape and 18mm hardwood ply on top.
Walls will be 12mm ply, 3x2 or 4x2 studding with rockwool in, breathable membrane, batons thenbarn style feather edge cladding.
Pent roof at 5 degrees,made of 80mm insulated roofing panels, maybe with 75cm hangover at the front and 50 at the back.
I have bought upvc french doors and 4 windows already.

My first query is regarding the amount of blocks, spacing of blocks and the design of the floor.
I've drawn out my initial plan and attached it.
Are there enough blocks? Is using 6x2 overkill? Perhaps there's a better way to do it?

I look forward to hearing from you

personally I would dig out the ground and pour 10 - 12 inches concrete, celotex can go in if needed and wood can go on top inside. Every home workshop i have built in wood have required ongoing repair work, rotten timber be it cladding or door frames. I have now turned to plastic, finding free or cheap conservatories on fb or gumtree,timber and felt roof. good units out there as enclosed.

 

[Sachakins]

I'd put the blocks onto concrete pads that can be easily levelled that way.
Spacing for blocks I would suggest no more the 600mm centres. In each direction, ideally I would have them under each joist and at 600m centres along each joist.
It's overkill at the outset, but the benefit is you can place heavy machinery where ever you want in your workshop. Nothing worse than finding the ideal position for your machine, only to find the floor sagging due to insufficient floor support.
On my last build of 24' x 8' I went for a solid foundation, more expensive, but easier to level at only 8' 6". TBH at 12' width id go the pad and block route, with them under each joist and at 600m centres along each joist.
Massively cheaper and almost as good as a solid foundation

 

[Mr Christopher]

What are the concrete blocks standing on/in? Depending on the load and vibrations they're likely to subside. You should also think about the internal loading - do you have any heavy equipment going in?

The concrete blocks are cemented upon a reinforced concrete base/pad. It was designed so as to take a Massey Ferguson 135 plus other lighter machinery and the inevitable 'stuff'