Is there any need for 150mm

[2019]

As the title says. Is there any need for 150mm stone under a slab of concrete in a garage if it's solid ground with 50-75mm of broken limestone chippings that's settled 20 years.

Im thinking why the need to dig down 200mm to replace with 150mm of stone and 50mm of sand then roller it when I already have a settled area with good building ground with 50-75mm of stone already there. I use this area for parking cars and is solid.

The garage slab will be 150mm with stell mesh.

 

[Leofric]

Is it necessary to have steel mesh reinforcement in the slab ?

 

[Ian H]

I didn’t on my garage. The ground was solid so I put the concrete over a dpm straight on the top.

 

[2019]

Is it necessary to have steel mesh reinforcement in the slab ?

No, not the mesh. I am asking is there any need to dig out solid ground to replace with 150mm of hardcore and sand. Sure I I could just put 50mm of sand down.

 

[Dereekoo]

If you were laying the concrete on rock you wouldn't consider taking that out would you so if you are sure you have a well compacted sub base go with that. Hit it with a sledge hammer and see how big a dent you put in it. Pointless putting any sand down. Re the mesh I assume Leoric was just questioning the need for that, whichever way you went. You don't need it from a structural point of view as the concrete will be in compression and not tension although it will help control shrinkage cracking if placed in the top face of the slab.

 

[2019]

It's

If you were laying the concrete on rock you wouldn't consider taking that out would you so if you are sure you have a well compacted sub base go with that. Hit it with a sledge hammer and see how big a dent you put in it. Pointless putting any sand down. Re the mesh I assume Leoric was just questioning the need for that, whichever way you went. You don't need it from a structural point of view as the concrete will be in compression and not tension although it will help control shrinkage cracking if placed in the top face of the slab.

The mesh will be 6mm or 10mm and for a large area, it'll help with the shrinking.

As for the base, will decide between now and next week will I dog it out.

 

[Mottie]

Is there any need for 150mm?

That's what I keep asking the wife!

 

[Ian H]

Is there any need for 150mm?

That's what I keep asking the wife!

Is she ok sticking to your 75mm?

 

[Leofric]

So wouldn't your garage floor level be 150mm above ground level if you put 150mm concrete on top of your existing limestone chippings base ?
Garage floors are usually at or 25mm above ground level.

 

[2019]

So wouldn't your garage floor level be 150mm above ground level if you put 150mm concrete on top of your existing limestone chippings base ?
Garage floors are usually at or 25mm above ground level.

My garage floor will be level with the dpc. The floor will be 150 above ground level. It'll have a small slope(ramp) of concrete when finished. If and when I get tarmac level with my footpaths, it'll bring me up close to the 25mm as you mentioned.

 

[2019]

Is she ok sticking to your 75mm?

If size didn't really matter, why isn't there no 3 inch dildos.