New concrete garage floor - depth at entrance

[kingandy2nd]

Hi all,

Hope everyone is well in these strange times. I'm continuing with my slow extension build, and I've finally started laying the foundation blocks. I've now come up with a question which I'd like some advice on regarding the garage door opening, and how to design the floor.

My plans just say: "150mm concrete slab, 1200 gauge DPM, sand layer, 150mm well compacted hardcore". Although not spec'd, I have ordered 7mm A193 mesh for this too.

Around the rest of the walls I have a single layer of 140mm high 7nm foundation blocks, but I am unsure what to do at the entrance to the double garage. I could:

1. Continue the run of foundation blocks, which will effectively hold the hardcore in place, and then concrete on top of the blocks. Meaning a continuous 150mm concrete floor, on top of the foundation blocks at the entrance.

2. Stop the blocks at the opening, slope the hardcore down to the foundation, add additional mesh, and shutter the opening and effectively have a 300mm think edge to the concrete floor which is all the way down to the foundation.

I have seen a diagram somewhere showing option 2, but I can't for the life of me find it now! So apologies for the crudely drawn pictures, but I hope it helps explain!

Any views on which is better option? I think 2 will give better strength but don't know if it's over-kill for a domestic garage. Garage door will be 4.8m wide if that makes a difference.

Thanks
Andy

 

[23vc]

Think you’d normally just shutter it, that’s how I did mine. Why have you got a foundation across under the door though?

 

[kingandy2nd]

Think you’d normally just shutter it, that’s how I did mine. Why have you got a foundation across under the door though?

Thanks for your feedback.

The foundation was designed by the engineer at the piling company. It's basically an E shape with the 3 tips of the E against the existing house/foundation...I guess this bit under the garage door provides some support to the outer parts.