Concrete grinding question

[almico]

I'm new to the forum and darn glad to be here. I'm planning on finishing my 20 x 28' garage to convert it into a workshop for hobbies, woodworking, coffee roasting etc. Since the house is built on a slab and there is no attic to speak of, I would like to use the rafters as storage space.

It appears that an addition might have been added to the garage years ago. There is the remnant of a cinder block wall running front to back in the middle of the floor. You can see it towards the bottom of this picture. How hard would it be to grind it away and what would I use for the job?

Right now everything is in the middle of the floor because I need to insulate the walls and add a ceiling etc.

 

[bimmer1980]

You need a good angle grinder and a diamond cup wheel. It will take some time....

Hopefully the cinder block will grinder easier than concrete....

This is one option...probably at the low end of price range....
Harbor Freight: Warrior - Item#98729
http://www.harborfreight.com/4-1-2-half-inch-diamond-turbo-cup-wheel-98729.html

A diamond grinding wheel will be faster than a regular abrasive grinding wheel.

There may be other tools that you can rent that may be quicker or easier...but not sure...

 

[almico]

Whoof!! That might be a little to much elbow grease for me. At 53 I just had my first, and hopefully last, heart attack last year, so conservation of energy will be paramount in this project!

I just called Home Depot. They have a grinding disc that bolts up to their floor sander. Might be the way to go for $100 for the day.

 

[schor]

If it's cinder block it should break up easily, try to score the block at the floor and then bash it out. Clean the rest up with a pneumatic chisel and then fill any holes back up with concrete.

 

[almico]

If it's cinder block it should break up easily, try to score the block at the floor and then bash it out. Clean the rest up with a pneumatic chisel and then fill any holes back up with concrete.

It's block, but the holes are filled in with concrete.

And from my experience, nothing works as it "should". If it weren't for bad luck, as they say, I'd have no luck at all.

 

[ScaldedDog]

I'd suggest scoring it, then attacking it with an air chisel.

Mark

Sent from my SM-N900V using Tapatalk

 

[pattenp]

If you have to remove more than an 1/16 of an inch the Home Depot floor sander/buffer with the concrete floor prep disks are not going to cut it. They are used to surface prep concrete for paint or epoxy and are used to remove old finishes from concrete. You need a concrete grinder or scarifier. I know because I've been there and done that.

 

[almico]

If you have to remove more than an 1/16 of an inch the Home Depot floor sander/buffer with the concrete floor prep disks are not going to cut it. They are used to surface prep concrete for paint or epoxy and are used to remove old finishes from concrete. You need a concrete grinder or scarifier. I know because I've been there and done that.

Yeah, that's what I'm afraid of. It's probably up to an inch in some places.

I guess it's time to get that compressor. I'll need it for the nail gun eventually anyway. I used to have a beautiful old 80gal Wayne back in the marital dwelling. No more marital, no more dwelling and no more compressor. Damn I miss that compressor.

 

[pattenp]

Rent a SDS hammer drill and use it in hammer only mode with a chisel. Get the surface just below the adjacent concrete and fill with leveling grout/concrete.

 

[almico]

Rent a SDS hammer drill and use it in hammer only mode with a chisel. Get the surface just below the adjacent concrete and fill with leveling grout/concrete.

Got it. I think another issue might be that the two sections are not the same height. I have a feeling the addition side has settled and might be lower. Nothing is easy...right?

 

[Whirnot]

I have used an angle grinder and diamond wheel for small jobs such as this and it wasn't as bad as expected. But if you don't have a quality angle grinder you might burn it up. Keep the concrete dust out of it as much as possible.

 

[almico]

I have a Dewalt DW402 angle grinder. Not sure if that qualifies.

But I have an update. I feel like an idiot, and I guess I should have looked closer, but it appears there used to be cinder blocks there, but they were removed leaving behind just the mortar.






So it appears I can chip away the mortar and be halfway home. The two slabs are still uneven though.

 

[Uncle Ben]

Wow, a coffee roaster AND a woodworker?! Me too!
What is your chosen method of roasting coffee? I've tried a few different methods over the past year or so and have ending up using a whirley pop with an electric drill hooked up to it.

Back on topic...I have used the 4 1/2" diamond cup wheel from HF and was very happy with it, but my use for it was to grind paint off a concrete patio that would not come off with muriatic acid or a 3,000psi pressure washer. I measured the cutting surface thickness on the wheel at the beginning and end of the project and it seemed to be exactly the same, so I was pretty happy with that. Anyway, I think that anything that you can't chip off your floor could easily be removed with that wheel.

Good luck!

 

[big.jim]

chisel the mortar off then use self leveling compound

 

[Mark118]

Mortar usually is a tad softer than concrete. Chip everything you can with a chisel. Get a
7" Diamond cup with an aggressive grit, say 30-40. You'll be shocked at how quickly and cleanly you can dispense with that. Some sort of dust shroud for your grinder connected to your shop vac is essential. In an afternoon's time you'll be standing back proudly admiring your work. Good luck with your project and happy roasting

 

[almico]

Wow, a coffee roaster AND a woodworker?! Me too!
What is your chosen method of roasting coffee? I've tried a few different methods over the past year or so and have ending up using a whirley pop with an electric drill hooked up to it.

Good luck!

I'm using the Turbo Crazy method. It's basically a West Bend Stir crazy on the bottom and a Turbo convection oven on top. Google Turbo Crazy and you'll get the idea. I also installed a thermo coupler on the bottom to monitor the roast. I'll post a pic when I get home tonight. It works a charm.

I got a mason's chisel and started chipping. It looks like it will come off. The trick will be to get my kids to do it!

I started looking into self-leveling cement to finish off the job and get the two slabs even. Anybody use this stuff?

 

[Uncle Ben]

Yep, I know exacatly what you're talking about, and I have wanted to "make" the turbo crazy for a little while now, but have been waiting to come across a cheap oven, and one that gets hot enough, so I haven't gone that route yet.

 

[retfr8flyr]

Op I will make a suggestion you may not have thought about. When I did me garage floor last summer, I rented storage containers from a company called SmartBox. http://www.smartboxusa.com/ They were cheaper then anyone else in my area. They bring it out and set it in your drive and then pick it up when you are through, all included in the quoted cost. I put all my stuff in the Containers and had the garage empty. It makes working on the floor so much easier that it was well worth the cost.

No matter which way you decide to go with the floor, you are going to create so much dust mess, that everything you own will be covered with it. You should look at what storage is available in your area.

 

[coryfavreau]

knee pads
SDS hammer drill
flat chisel
2 beers

If you're picky you could feather finish over the resultant scars but I'd only do that if youre going to put a flooring product on top - i.e. tile, VCT, etc. A feather finish or self leveling compound may break up on a skim coat and heavy floor use (jacks, cabinets, tools, etc) if left as the final surface.

 

[Krodad]

the right way to do it is to use a demo hammer with a wide flat chisel to get rid of the existing mortar, and switch to a slightly smaller chisel head and pick a place out where you will stop the skim coat and chisel out about a 3/4" deep tapered key where the mortar will stop, rather than taking it to a feather edge.