I am starting a business and I have about 3000 square feet of concrete that I would like polished. My contractor says it will be around $20 per square foot (i love NYC) so I was considering doing it myself.

I looked up some how tos online and I wanted to get an idea from the board on whether this is one of those jobs better left for a professional. From what I have seen, it seems like it is just a really really tedious job. But if you follow the right steps, it's not that hard to do. This is going to be a place for manufaturing so I am just trying to polish up the floors for sanitation purposes, it doesn't have to be gorgeous, just functional.

 

If you want it to look good, it's better left to a pro. If you want functionality only, I'm sure you could do it yourself. It's basically just grinding with progressively finer discs, and then applying chemical densifiers. If you've got a lot of spare time and you can accept less than professional results, go for it.

 

If the floor is basically in good shape, some of the epoxy coatings are impressive. To me, polishing the concrete is either for the purpose of leveling it or bringing out the natural look of the stone. But if the stone wasn't selected before the concrete was mixed, you only get what is there, far less than some of the selected stone mixes. A Delaware river bed mix looks incredible when polished.

If the epoxy can go directly on and seal things up, might be an easier step. Otherwise, as Pecos stated, it is just a lot of work and a rental machine.

Bud

 

A number of years ago one of my clients had an exposed aggregate floor in his building that he didn't like and he wanted a smooth surface. After a fair amount of research, I found that it could be ground down but it was very expensive. The grinding could be done in the same way that terrazzo is ground. The reason it was so expensive is that the aggregate (rock) used in a conventional concrete floor mix is much harder than the aggregate used in a terrazzo mix. That translates into a lot more labor and shorter life for the grinding pads.

Was the contractor you talked to a general contractor or a terrazzo contractor? If a G.C. try talking directly to 2 or 3 terrazzo contractors.

 

The contractor I talked to was a GC.

I'll take some pics of the floor and post them when I get a chance. I'm not familiar with the epoxy method, what is that exactly? Is it like staining and varnishing a wood floor, but for concrete instead? That might be the route to go and that would be a whole lot easier that polishing. Again it isn't for look it's for sanitation purposes and because alot of liquid will get spilled on the floor.

 

There are several brands of epoxy and it is essentially a paint. They sometimes sprinkle colored flakes all over it to make it look pretty . Last I was involved with was a garage floor. Really tough use and it didn't hold up that well, but I certainly wouldn't blame the paint/epoxy, they were terrible. Our local car dealer did their entire service area and it has held up well, but they aren't slobs.

Stain is another path, but I have no experience with it. Others here have and maybe they will jump in.

Bud

 

With what I think you are describing, you definately need a commercial grade epoxy coating, not the stuff sold by the local DIY stores. It is still going to be expensive, but probably not as expensive as grinding the floor.

I was involved in the design for a City vehicle maintenance garage about 4 years ago. We used an epoxy coating in the maintenance bays; I believe it was a 3 coat system. I'm sorry, I don't recall who the manufacturer was and the files are now in dead storage. But I do recall that the name of the game was floor prep. Even with a new concrete floor, the installers had to lightly sandblast the entire floor. It was all about being completely free of any type of contamination. There was 1 area they missed and they had to come back and strip the epoxy and redo everything in that area. So probably not a DIY project.

 

"But I do recall that the name of the game was floor prep"

Worth repeating

It can be difficult to get a lasting job with paint on a concrete floor. It pays to use good products but if the prep isn't done right, it would have been just as good to paint it with something cheap Another thing to consider is moisture, not on top of the coating but coming up thru the slab - if that happens, it will be difficult for any coating to survive.

Concrete stains work well, in part because they are a little more forgiving in the prep dept. They won't wear as long as a good epoxy coating but they are easy to recoat.

 

It just occured to me that you might try a surface hardener like Sonneborn Lapidolith. Thats a liquid that goes on over concrete and reacts with the concrete to densify and harden the surface. It's actually something you could do yourself. You can get it at contractor supply houses; you might even buy a pail and see if it does what you want it to.

 

Yes I spoke to a local hardware store owner and he said the main thing to keep in mind was the prep work before adding the epoxy. He mentioned that I should make sure the grease is removed and to do an acid wash before using the epoxy.


Sonneborn Lapidolith - Looked up some info and it looks like it would work but also looks like death in a pail. I don't know if I'd feel safe working with something like that.

http://www.buildingsystems.basf.com/...ts/lap_msd.pdf

Is this something to be really concerned about or is it similar to using oil based paints and thinners. Just make sure I use it in a well ventilated area.

 

I actually used Lapidolith on my garage floor a long time ago. It wasn't bad at all with proper ventilation. You are correct in that you definately have to take precautions like you would with solvents or paint thinners. Actually, I'm very impressed that you went to the trouble of looking up the MSDS sheet on it!

 

When you said "the guy at the local hardware store", it sent up a red flag with me. You will not find the proper grade of products at a hardware store or big box store. You need to go to a local contractors supply and talk to them about your project. They can not only rent you the equipment, but also teach you to use it and sell you the professional grade materials you'll need.
I agree that epoxy would be much easier and quicker, but do not use epoxy from a "hardware store" because they are cheap, thinned out homeowner-grade materials. They're made for folks who want to paint their garage floor, not coat an industrial slab.
Professionally installed epoxy flooring systems are thick and nearly bulletproof, whereas the homeowner brands are thin and go on like paint. The differences are truly like night and day.
As long as you're checking into different options, look up polyaspartic polyurea (PAP). It might be more what you're looking for. Good luck.

 

Yes I just went to the hardware store for an opinion, not to purchase. For prep I was thinking of renting a shot blaster, it seems like a really easy way to prep the floor:

YouTube - www.concreteideas.com - Concrete topping surface preparation

Also, the floor is currently covered in wood, so I'm sure when that is pulled up, there will be glue to remove. So my plan of attack is:

1. pull up wood floor
2. use a scrap away disc : YouTube - remove carpet adhesive floormagic biz
3. Use the shot blaster
4. Put on the epoxy coats with a kit like this: Commercial Floors and Hangars | Armor Poxy

 

hmmm polyaspartics seem like a good option too. So many choices I might pay a professional just so I don't have to make any choices.