Grinding floor

[Dave Maxwell]

OK how hard is it for a first timer? As seen from my pour thread. My floor *****. I'm thinking of grinding it myself. Either that or the building becomes storage. Went out there today and couldn't stand it. Had to leave

 

[Shea]

Grinding garage floors has gotten easier for first-timers thanks to Diamabrush. Here is an article on how to grind your garage floor that is geared towards the first timer. It's not that hard to do once you get the hang of what you are trying to accomplish.

I helped a friend from another state grind his floor this way a while ago since I traveled by plane to his house and it wasn't feasible to bring tools with me. It works fantastic and goes fairly quick compared to traditional grinding. We even had time to apply a primer coat that afternoon since he used a water based primer that worked fine with damp concrete.

 

[Dave Maxwell]

Might try that. I'm worried about stripes and having a smooth transition between passes

 

[pauls_workshop]

OK how hard is it for a first timer? As seen from my pour thread. My floor *****. I'm thinking of grinding it myself. Either that or the building becomes storage. Went out there today and couldn't stand it. Had to leave

hi Dave, see some of my recent threads. I am using just a 4.5" hand angle grinder with a good dewalt diamond wheel to do my whole 1 car garage basement workshop space. Can be done this way very cheaply but does take the most time. For 2 or 3 car garage spaces, probably renting a larger grinder is a good idea. The real floor grinders are much faster and give a flat surface but cost $$$$ to rent. Even with one of these, if your floor is not very flat now, I have found the little 4.5" size wheel ideal to smooth out smaller areas that are lower than the surrounding plane of the floor. You can do a relative local smoothing without needing to remove another 1/8" off the whole floor using something small like this locally only and blending into the larger plane of the floor. The bigger size grinders aren't good at that at all. Also very useful for all walls and corners. After killling my little 4.5 amp harbor freight grinder, I'm currently using a robust 8.5 amp black and decker (which cost all of $40 not on sale at Menards). The underpowered grinder is GREAT in avoinding any digging in even with the 4.5" wheel and avoid any trouble! My floor is perfectly flat with it! The 8.5 amp grinder is MUCH faster but also MUCH harder to control. I have to move fast with it and be more careful, especially in a few softer areas on the floor. It is just great on the harder areas. So with a little hand grinder, there are real uses for a lower powered and a higher powered one. But I see a use for a little hand grinder wheel even with a larger floor grinder rental if you do it yourself. If you get one, be sure to buy or make your own dust collection system for it for shop vac connection and also use a "drywall dust bag" or "fine dust filter bag" on your shopvac. I made my own dust collection system for my grinder using a 5" metal cookie tin, cut to fit, and a connection to the shop vac. Works great and saved $25 and took me about an hour to make. It was fun! - Paul

 

[Dave Maxwell]

Thanks paul. Great advice. Mine is 42x72. I do need to knock some of the big spots off with my little one will probably need bigger after that.

 

[neel2008]

Id like to see pics of what you end up doing....my garage floor is all wacky and uneven and it drives me frekin nuts....I talked to the local rent a center guy about renting a drum style grinder to do mine....I want to knock out the high spots and see if I can grind a slope into it towards the door where I am going to install a grate style floor drain along the door....Id guess Im going to need to remove well over an inch in some places....but the floor is like 8 inches thick so im not worried about how much to remove....I just think it is going to be a huge pain in the ***....

 

[Dave Maxwell]

Will post some. Hope to be doing something soon

 

[Dave Maxwell]

Guy stopped by and said he could blend the spots but it still could have highs and lows because the grinder only covers about 3 feet at a time. Is it possible to get 3000 s/f level after a bad pour

 

[gobble]

I rented the Diamabrush from Home Depot for $100 for the day. It takes time. It does a decent job of scratching the concrete. Don't plan on it to do much to even out any high or low spots however. In 5 hours of grinding I collected less than a 5 gallon bucket of dust.

 

[LegacyIndustrial]

Gobble good point. However that tool coupled with a hand grinder is a great way to prep a floor. We have many clients relying on the Diamabrush product for flooring businesses.

 

[Dave Maxwell]

He said he couldn't get all the highs down and blend whole floor without some height difference. If I knock the bads down by hand first will that help. Also with a 70 grit cut, will it be good for epoxy. I can't cover it right away. Can I use the floor for awhile this way

 

[LegacyIndustrial]

25 grit for aggressive removal/ prep.
100 grit for just enough to profile.

 

[Dave Maxwell]

Think his plan was one pass with 70. Then rest is up to me. Said it would be open then and need sealed

 

[Edger]

Don't forget to use protection when you grind.

Here is a 1min. video, enjoy.

 

[LegacyIndustrial]

Edger:
Welcome back and yes you are a marketing genius!!
When can we expect the next episode?

 

[Shea]

Classic "No, I'm serious honey. I really do need this!"

 

[Edger]

More episodes are planned for this year. Subscribe to the YouTube channel to keep up, should be fun.

 

[Dave Maxwell]

So with a 70 finish will it be extremely rough.

 

[LegacyIndustrial]

Dave, what tooling are you using?

 

[Dave Maxwell]

I don't know to be honest. Said it was about 3 foot wide and had two heads. 3,000 to grind. 1 per foot. Is that price good. That's for one grind . Not multiple steps

 

[LegacyIndustrial]

Sounds like an edco. As long as he makes it ready for coating, I am good with it.
Yes. 1.00 per foot is the norm.

 

[Dave Maxwell]

I just want it flat for know. I don't have the funds for coating. It was suppose to be flat to start with. As you can are from my pics its not close

 

[LegacyIndustrial]

Anyway you can hold off till coating? You are increasing your chance for contamination by operating on an open floor. It will be a dust generator too.

 

[Dave Maxwell]

I've got to get moved. Suppose to be a working shop by bow.now. if I did the grinding I could coat now. The contractor is paying for the grind. I could grind and use his money for paint. Ill never pay anyone a down payment again

 

[Dave Maxwell]

If I let him knock it down. What grit would I need to finish it like a sanded floor. Do I still need to cover it if I ground more. Do the highly sanded floors have a coating. What is densifier and what does it cost. Thanks and sorry for all the stupid questions

 

[Dave Maxwell]

Here is some of the spots I want to get flat to go with rest of floor after all ground.

 

[LegacyIndustrial]

Dave:

There is grinding for coating prep and grinding for esthetics, usually followed by polishing heads to get the full effect.

Making a floor look smooth and polished requires expensive tooling to achieve.

 

[Dave Maxwell]

Wondered about that. Should I cut that down with a hand grinder first

 

[Dave Maxwell]

Well contractor is whining about grind price. He signed a notorised paper saying floor would be repaired. I even offered to pay to seal it. Its not my problem, but trying to help. Getting lawyer involved. Now he will be expected to pay for whatever it takes to get floor to the finish I was promised. I assume it should be pretty straight forward with a lawyer involved and signed documents

 

[Red Goat]

Getting lawyer involved. Now he will be expected to pay for whatever it takes to get floor to the finish I was promised. I assume it should be pretty straight forward with a lawyer involved and signed documents

I thought you said you needed to get moved in quickly?

 

[Dave Maxwell]

I do. But can't use floor like this and all the stuff I would have to take back out I won't have a place to store it. This is costing me money. Lawyer can light a fire under his ***

 

[LegacyIndustrial]

He will likely have to pay a real polisher to come in. This likely above his head and pay grade . You can't make a floor look pretty or even decent using a grinder alone.

This job needs a large multi head polishing machine.

 

[Dave Maxwell]

Guy from garage flooring. Com came over last night
and said he could grind it for 1 per foot. And stay it for. 50 a foot. Said it would be smooth and better than epoxy. Chemical and graffiti resistant guarantee. Anybody know this company

 

[LegacyIndustrial]

Dave:
Get references, pictures of past work and a written proposal describing exactly what is going to be done.

 

[Dave Maxwell]

Thanks. Grinding. 3,000. Said he would fill any pop outs that already occurred and do seems. Then apply the top coat for 1500. I don't know the company or anything about them sleep. Did a Google search for grinders in Peoria Illinois. Will check him out. If anybody has an operator in this area, let me know

 

[LegacyIndustrial]

Be interested to know the topcoat is.
Can you get a technical data sheet?

 

[Dave Maxwell]

Will do. He said it is chemical resistant and heat to 600. Graffiti resistant also. Comes with a written guarantee. Said I can pick color. Will see

 

[Dave Maxwell]

Talked to lawyer. He said contractor is screwed 9 ways from Sunday.with signed document with him stating floor is messed up. Told lawyer prices are $1 per square. If any companies on here don't mind me quoting the price. Please state price and let me know if its OK to use it as a reference also. Thank you. 2911 s/f

 

[thomaskept]

Floor grinding is difficult. First time start grinding the surface of the concrete by slowly working the machine side to side. Floor grinders are a much faster process. When wet the surface of the concrete that you are going to grind so that you won't produce any dust, so that time work carefully. And one thing always takes on the mind for grounding floor to do clean any oil or grease spots otherwise concrete not split very well.

 

[Bruce27834]

Hello,..I've read this thread and i have a question or two about grinding i didn't see answered exactly to my issue.. I'm a member of a volunteer fired department..we recently did the mistake of applying a epoxy from sealcrete down...one layer of primer and one layer of the epoxy paint..it is coming up where the tires rest and anywhere water sits..We have contacted the manufacturer and we have been told if we get the lowes we purchased the product from to call this particular rep and tell him they advised us to use this product the company will refund our money because the rep says this particular product isn't designed for floors for the weights we are putting on them..SO..we have to grind up or strip the floor and redo..Will this diamond cutter pad for the floor machine do the job we need to do? And we have another building we haven't done yet and that building had a polyurethane sealer put on it about 25 years ago. Will this same diamond head take that off for that project as well? ..Thank you