Part block part timber build?

[ILikeDIYS]

Hi. Still confused on whether I want timber vs block build for a summer house.

Had the idea of doing the back wall in thermalite blocks and all other 3 walls in insulated timber... would this be a bad idea? Reason being is that the back wall of the old shed was totally rotten.

Also would this foundation hold up blocks well enough:

That's what I got so far. The footings all the way around range from 200-250mm depth to where you see; then on top of that will be a 200mm slab.

Also, is it OK to put an additional DPM on top of the 200mm slab after it is poured/set?

Also x2 I want to build a block perimeter, then have the timber sit on top of that, would I have to fold all the DPMs (external and internal) to go on top of the blocks and held down by the timber walls?

Feel free to point out any issues so I can rectify before it's too late lol

Thanks in advance.

 

[noseall]

Feel free to point out any issues so I can rectify before it's too late lol

Thanks in advance.

Yes, why don't you build up a few courses of engineering brick to get out of the potentially troublesome ground first? You have designed it similar to a raft but without the benefit of the external concrete height reduction that comes with a raft.

Me - I'd hoof out all the reinforcing, lay say three courses of engineers, lay a new DPM inside and lap it onto the bricks, re-fit the mesh (probably not needed) and pour the slab.

The I'd decide whether to lay anymore masonry (perhaps two courses) to get me above floor level before starting any timber structure.

 

[^woody^]

If blocks are going around the edge, it needs a reinforced edge detail to prevent it shearing

 

[noseall]

If blocks are going around the edge, it needs a reinforced edge detail to prevent it shearing

It looks to me like he has a foundation in place. Hence my reference to a raft.

 

[ILikeDIYS]

If blocks are going around the edge, it needs a reinforced edge detail to prevent it shearing

You mean the concrete might slide/crumble down at the edges under the weight of the blocks? What does edge reinforcing look like and can it be applied after the concrete is poured (but before the blocks)?

Me - I'd hoof out all the reinforcing, lay say three courses of engineers, lay a new DPM inside and lap it onto the bricks, re-fit the mesh (probably not needed) and pour the slab.

Man I wish I read your post first because that seems like a good idea but unfortunately the concrete is down already lol

And to make matters worse I ran out of ballast so have to continue with the rest of it today (hopefully won't cause issues) it's about 80% filled.

As for the ground around I'm planning to scrape some layers of the mud off to lower it to below the concrete and level out the garden a bit.