Small studio in garden

[DodgySailor]

Dear all, I have disassembled the shed in my garden which was on top of a concrete floor about 3 x 2 metres and would like to build a small studio there. Is there any way I can make the studio a bit bigger by "overhanging" a bit over the concrete base so that I do not need to make the concrete floor wider? If this is possible what is the technique?

 

[mrrusty]

If the base is sound and solid, you could supplement it with easypads https://easypads.co.uk/ and then build a timber sub-frame supported by both. However, is it really sound? or is it just 2" of concrete on top of topsoil? - depends what you are going to build, but if it's substantial it needs substantial footings whether that's traditional strip foundations, easypads, screw piles.....

 

[DodgySailor]

It is quite solid but I need to investigate further how deep down it goes, These easy pads look like a good idea for this. Thanks!

 

[mrrusty]

If it helps with inspiration, here's my fairly recent build https://community.screwfix.com/threads/garden-room.256842/

 

[Ivor Windybottom]

Or you could do it right and extend the concrete base.

You should put some screw-in wall ties into the edge of the existing and concrete them in, to hopefully prevent differential movement between them.

 

[DodgySailor]

No way I am doing something like that!

 

[mrrusty]

No way I am doing something like that!

Maybe not, but simplysips do kits for smaller buildings which might be useful to you. The advantage of SIPs is you get both the insulation and the structure in modules that go together like lego (well nearly ) https://www.simplysips.co.uk/product-category/kits/

 

[Ivor Windybottom]

Build one of those tudor houses that gets wider as it goes upwards...

 

[Deluks]

Build one of those tudor houses that gets wider as it goes upwards...

They're designed like that so you can empty your ****epot out of the window and not mess up your walls.

 

[Ivor Windybottom]

Thanks, I always wondered why the old lady in the flat below always looked a bit annoyed with me.

 

[ToolboxTalks]

You can overhang a little, but only if the floor framing is strong enough and you keep the overhang small. Most people use cantilevered joists for this, but it has limits and you need the right spacing and length. If you want more than a small bump out, it’s usually easier to pour a bit more concrete or add proper footings beside the slab. It keeps the structure solid and avoids problems later.

 

[Ivor Windybottom]

The vast majority of the weight of any building is in its walls, they weigh lots plus they also hold the roof up.

If you dangle them off the slab then almost all of the weight will be over fresh air. Your existing slab won't really be holding anything up - you're basically building on soil so should treat it as such. i.e. build a proper foundation.

Or you could use slabs or sleazy-pads on top of the soil, in which case it will look great for a year then will sink, buckle and collapse over the following years and you'll wish you'd paid a bit extra to do it properly.

It would be a really silly thing to do. Proper foundations extend beyond the outer wall, to spread the load. If there really was a good way of building for less then every housebuilder would already be doing it. There's an obvious good reason why they don't.