Concrete grinding

[whateg01]

It's been a particularly wet year and it seems every raindrop has been accompanied by 60 mph winds blowing the rain against the overhead shop door. When that happens, the rain runs under the door.

The floor is flat out to the outside of the wall instead of relieved at the door. It sits about 1/2" above the slab in front. I'd like to grind a slope in the door opening which would make it easier to keep water out and also make it easier to roll stuff in without having to lift it or use my little ramps.

Has anybody used a grinder like this for that purpose? What concern is there if rebar or remesh is exposed in the process?

I haven't priced having it done but I would prefer to do it myself if possible. It is difficult for me to schedule stuff to be hired out for to work travel.

 

[egdede]

Sounds more like a job for a handheld angle grinder.

 

[gmcgeo]

If you hit rebar or remesh
Surface-level rebar isn't common unless it was poorly poured. But if you do hit it,
Structural integrity is not a major concern if it's only slightly exposed and not cut or heavily ground.
Corrosion risk increases if exposed and moisture gets to it.
Seal it after grinding (epoxy or concrete patch compound).
Remesh (wire mesh) is thinner and more likely to be exposed if it’s shallow. Again, sealing or patching is key.

 

[Hooked]

Here's some info from a couple years back when someone did the grinding. Might try some additional searching on here.

Garage door entry not sloped

Hey there. Looking for some ideas on how to address the issue of my garage door entrance being completely flat. There was no slope put in front of my garage door and occasionally when it rains hard some water leaks back under my door. I have searched and seen some mentions of making cuts with a...

www.garagejournal.com

 

[whateg01]

Sounds more like a job for a handheld angle grinder.

Sounds like a pita to be on my knees with an angle grinder grinding roughly 16' of concrete back 8 or so inches.

 

[dcg9381]

So the contractors that poured my slab "missed" the recession for the garage door. I would have had the same problem as you, which is water under the door (and into the house). This "garage door" is on my office.

I made them fix it. What they did is went in and cut out lines with a saw, then chipped out, a 1" depression. They then covered it in some sort of concrete designed for the job - some sort of skim coat. It worked great. I was not easy work though... Skim coat was a slightly different color, but as this is a water based stain floor with polyurea, I doubt anyone notices.

 

[Codyboy]

So the contractors that poured my slab "missed" the recession for the garage door. I would have had the same problem as you, which is water under the door (and into the house). This "garage door" is on my office.

I made them fix it. What they did is went in and cut out lines with a saw, then chipped out, a 1" depression. They then covered it in some sort of concrete designed for the job - some sort of skim coat. It worked great. I was not easy work though... Skim coat was a slightly different color, but as this is a water based stain floor with polyurea, I doubt anyone notices.

That looks like how I would do it.
Saw cut down an inch and chip it out. Then grind it flat maybe.

 

[Leon bee]

I was hired once by a woman who had an inside floor needing ground down. My job was to act like taking it seriously, and then convince the husband it couldn't be done.