Refurbishing a concrete floor

[improperyour]

I have a concrete floor in the garage that was poured 30+ years ago (at least). It's held up remarkably well I would think, with some cracks and chips but overall pretty smooth.

Except the previous owner painted 2/3rds of it with some gawd awful amber-brown color (the whole garage was brown inside -- so they apparently liked that color). The other 1/3rd they put carpet down, which came up mostly pretty easily though with some damage and marks.

I want to restore (refurbish?) the floor back to a nice smooth concrete. But I am not a concrete person, nor a floor person, so have no idea if this is possible. Can you grind it down (as if you are going to put on an epoxt coat or something) and then smooth it out so that it has the nice finish (such as you would see at HD/Lowes)? I can give it a really nice polish looked, perhaps even a tint.

I was thinking of just going epoxy, but I do like the characteristic of concrete to absorb (and then let dry) water. We park two cars in there and while we don't have snow, we do have rain and having that quickly dry off rather than puddle up (and create a slippery surface) with epoxies and such.

Or is this just not possible and I should just grind and epoxy for a nice look? Note - I did try and pull up the paint, but that worked marginal at best. Of course, I have no idea what type of paint was used.

 

[Matty J]

You can definitely get a nice concrete floor similar to a polished look, but it just depends on your budget and if you want to DIY or hire it out.

I own and operate a concrete and coatings company, but im not here to pimp products or anything...just offer advice. What you would probably be looking for would be either a polished concrete system, or a "grind and seal" or "grind, stain and seal" if you wanted to add some sort of color to the concrete.

A grind and seal would be more DIY friendly, as polishing require a lot more sets of tooling for a grinder. Essentially, you would rent a floor grinder (ideally a planetary grinder with 3+ heads) and probably start with like a 16 grit or 30/40 grit set of metal bond diamond tooling. This would be the first step to removing the existing coating, and "cutting the cap" of the concrete so it will have a profile to accept the coating properly. After that step, id probably do one more grind with a 60/80 grit set of metal bond diamond tooling and then you could apply the sealer, or a stain and then a sealer. For a sealer that is more DIY friendly, I would probably recommend a solvent based polyurethane.

Glad to help if you have more questions!

 

[improperyour]

This is good info, I appreciate it. I will hire it out, I'm doing electrical, plumbing and drywall. But I am wanting a professional to do the floor, otherwise I know it won't turn out the way I want it.

I wasn't sure if you could repolish concrete, and didn't want to look like a dolt for asking around town (much easier to look like a dolt on the internet). Now that I know it's possible, I will be giving a few concrete shops a call and seeing what they say.

What would you consider a cost for a polished concrete system (per square foot) vs. "grind stain and seal"? My garage is about 650sqft total - and my budget is probably in the $7-8/sqft range.

 

[Sumboodie]

For that price, could pour a new slab!

 

[Matty J]

For that price, could pour a new slab!

Not if you have to rip out the existing slab. You'd be much closer to $20/sq ft with rip out and repour (At least in my area of Charlotte, NC). New mono slabs on level ground will start around $10/sq ft,

 

[Sumboodie]

Not if you have to rip out the existing slab. You'd be much closer to $20/sq ft with rip out and repour (At least in my area of Charlotte, NC). New mono slabs on level ground will start around $10/sq ft,

Ripping it out would just cost me time and fuel.

 

[Matty J]

Ripping it out would just cost me time and fuel.

lol yea well not everyone has a jackhammer, demo saw, skid steer, 3/4-1 ton truck, dump trailer, etc.. to handle that side of things. If you do, then you can save a lot of money.

 

[Matty J]

What would you consider a cost for a polished concrete system (per square foot) vs. "grind stain and seal"? My garage is about 650sqft total - and my budget is probably in the $7-8/sqft range.

Everything is job dependent (existing slab condition, what kind of repairs are necessary, access for equipment, travel distance, finish desired, etc), but in a solid ballpark world, I would probably be at like $5.50/sq ft for a 400 grit polish finish, $6.00/sq ft for an 800 grit polish finish and maybe $5/sq ft for a grind, stain and seal. I've seen grind and seals being done for like $3.50/sq ft, but in terms of job size, yours is relatively small and a reputable business should have a minimum job price as it does take a lot of effort for mobilization of equipment. I usually have a minimum of $3,000 for a job unless it is something we can knock out in a day without cutting corners.

 

[Sumboodie]

lol yea well not everyone has a jackhammer, demo saw, skid steer, 3/4-1 ton truck, dump trailer, etc.. to handle that side of things. If you do, then you can save a lot of money.

Sounds like you just made a shopping list!

There's a guy trying to get a D7 going and park it in his HOA community!

 

[Matty J]

Sounds like you just made a shopping list!

There's a guy trying to get a D7 going and park it in his HOA community!

That shopping list for me is complete! I tear out concrete weekly.

And im not sure if that D7 is a Killdozer reference, but if it was, Im a big fan haha.

 

[Miss the Pontiacs]

Since you are willing to shop the flooring project out do a Polyaspartic floor. I did it in my garage and have no complaints and just love it. Lots of positive compliments as well.

 

[Matty J]

Since you are willing to shop the flooring project out do a Polyaspartic floor. I did it in my garage and have no complaints and just love it. Lots of positive compliments as well.

Polyapartic flake floor?

 

[Miss the Pontiacs]

Polyapartic flake floor?

Yes. Here is a quick pic. More if you are interested on my garage build.

 

[Sumboodie]

That shopping list for me is complete! I tear out concrete weekly.

And im not sure if that D7 is a Killdozer reference, but if it was, Im a big fan haha.

No, guy on here had a post about an antique D7. Killdozer was a Komatsu d355A

 

[improperyour]

Yes. Here is a quick pic. More if you are interested on my garage build.

What's the difference between a polyaspartic and an epoxy floor, from an end-user point of view?

I looked it up and it seems like an offshoot of epoxy, though your picture looks the same as I would expect from epoxy (perhaps a little less shiny)?

 

[PhantomEB]

When I get a wide open shop once again next summer, I plan a day of a respirator and aircraft stripper to strip this ****** concrete paint the previous owner put down. I rather have bare concrete or a clear sealer.

 

[Matty J]

When I get a wide open shop once again next summer, I plan a day of a respirator and aircraft stripper to strip this ****** concrete paint the previous owner put down. I rather have bare concrete or a clear sealer.

You may have similar results renting a buffer or a "square scrub" machine and running 60 grit sanding screens on it. Less exposure to harsh chemicals is better.

 

[Matty J]

What's the difference between a polyaspartic and an epoxy floor, from an end-user point of view?

I looked it up and it seems like an offshoot of epoxy, though your picture looks the same as I would expect from epoxy (perhaps a little less shiny)?

not much. The main three options for a base coat on a flake floor are epoxy, polyurea, and polyaspartic. Each one has it's pros and cons. Polyurea and polyaspartic (especially polyurea) seem to have some crazy sales-pitchy claims behind them like "4X stronger than epoxy" or "Lifetime warranty" (which are BS warranties when you read them.)

Most flake floor systems include 3 layers which would be your base coat, flake broadcast, and then topcoat, with an optional primer coat before basecoat....which usually isnt necessary but depends on the hardness and overall condition of the concrete substrate.

The main advantage of a polyurea or polyaspartic base coat for a flake floor is those jobs can be completed in 1 day.

My go-to flake floor system is an epoxy base coat, full flake broadcast, and a polyaspartic topcoat. Regardless of your basecoat, I would only go for a polyaspartic topcoat as it is UV stable and more chemically resistant. Epoxy should never be used as a topcoat as it will amber/yellow.