Blend Material Based on height

Hi,

I’m new to unreal and I would like to make a material where the blend operate like this



With a clear separation between the two diffuse.

For the moment my blend got this blur

I would like the bricks to appear fully or not at all, or at least remove this blur which don’t look natural at all…
Here is my material

I hope I was clear enough.
I looked on the web and everything I found was mainly about landscape blending

Thank you for taking the time to read this question.