Fixing slope on concrete patio - grinding a drainage channel?
We did end up renting a walk-behind grinder and it did the job.
It was not &quot;easy&quot; but only took a few hours, and the rental cost was reasonable. The ideal grinder we wanted was out of stock but would have had a smaller cutting width. However the one we used despite being larger still didn't take excessively long to do the job.
We had a small amount of water running the entire time which basically eliminated airborne dust, removed the dust, and indicated when the drainage was working well enough. We used that the judge when it was &quot;done&quot; rather than focusing on any exact measurement of slope.
In hindsight I think the job seemed intimidating but it was actually quite reasonable to do.