I'm looking to grind the edge of my concrete slab to create a slope away from my garage door. I have a 25x25 metal garage sitting on this slab in central NC, and the concrete currently slopes just slightly to the east—about 2 inches over 25 feet. The problem is that when it rains, if there's any wind from the west, water hits the garage doors, collects on the exposed concrete, and eventually leaks into my garage. There was no outward slope added to the slab when it was poured, and the roof doesn't overhang anywhere. My plan is to use a concrete grinding wheel on an angle grinder to create a slope of about 1 inch over 8 inches at the edge right in front of the garage doors. I'm worried about how I might mess this up. Are there safety concerns or properties of concrete I should be aware of?
6 Answers
Don’t forget to wear proper PPE! Concrete dust is super harmful. Based on your area, you're looking at around 12 square feet (6 cubic feet of concrete) to grind down, which seems like a long job with a grinder. Have you thought about adding drainage grooves instead?
Grinding is a bit of a hassle. If you're sticking with this plan, consider using a bigger grinder. You should also think about making some cuts along the width, and smashing them out to make the job easier. Afterward, a thin epoxy cement coat could smooth things out.
You’re on the right track, but remember it might take time. Safety gear is essential! I've worked on a few garage floors myself, and ensure they always have a slope. Good luck!
Check with rental companies to see if they offer larger grinders for this. Many times they have walk-behind models with very effective diamond blades that can help out.
You might be in for more work than you expect. Grinding down all that concrete with just an angle grinder could take forever! Instead, think about cutting out a 24" strip and using a jackhammer to remove most of it. That way, you can repour it with the right slope and maybe even add a trench drain to deal with the water better.
I’d suggest cutting a strip out next to the building and putting in a drain. It'll be way easier and more effective in managing the water problem.