New concrete onto old concrete help!

[Mark Lewis]

My barn has a concrete slab floor - as you step into the space the area just inside the door slopes up to the main area of flooring that is 90mm higher.

This means I lose useable floorspace over the sloped zone - So I want to add a step up (where the pink line is) of 90mm and fill in the sloped zone back to where the red line is. As the space is not vast and only taking footfall....can I just make a form to retain the concrete and fill that space with new stuff? If so, should I add someting to the current floor so the new bit stays where its should? Fix some ground bolts into the floor for the new pour to hold onto???

Any advice would be good - and talk to me like I'm an idiot at this stuff (i am)

Edited by Mark Lewis on Monday 27th January 13:53

[Mr Pointy]

There's no picture showing but the minimum step height for stairs is 150mm so maybe that's why they put a ramp in.

[Mark Lewis]

Mr Pointy said:

There's no picture showing but the minimum step height for stairs is 150mm so maybe that's why they put a ramp in.

Pic added! Good point about stairs - I'll put up a mind the step sign ! ))

[wolfracesonic]

To help mechanically fix the new concrete to the old, screw some expanded metal lathing to the old floor, s/s ideally if the floor is damp; alternatively a slurry of SBR/cement on the old concrete with some SBR in the new mix. The biggest I see is that it looks like the new concrete will have to finish to a feather edge where it meets the edges of the ramp, which is not possible with concrete. Have you an angle grinder you can put in a clean cut at the edges of the ramp and break out some of the old concrete so the new concrete has a bit depth to it where old meets new?

[Rob.]

You can't lay concrete to 0mm depth, so you would need to break out at least 30mm or so to tie it in.

[Mark Lewis]

wolfracesonic said:

To help mechanically fix the new concrete to the old, screw some expanded metal lathing to the old floor, s/s ideally if the floor is damp; alternatively a slurry of SBR/cement on the old concrete with some SBR in the new mix. The biggest I see is that it looks like the new concrete will have to finish to a feather edge where it meets the edges of the ramp, which is not possible with concrete. Have you an angle grinder you can put in a clean cut at the edges of the ramp and break out some of the old concrete so the new concrete has a bit depth to it where old meets new?

I just bought an angle grinder today for something else! Sorted ))

[Mark Lewis]

Rob. said:

You can't lay concrete to 0mm depth, so you would need to break out at least 30mm or so to tie it in.

do you mean it needs 30mm depth on the concrete at its shallowest point?