New Concrete Floor Finish

[groove grabber]

Yesterday I had a concrete floor poured in my garage by a gentleman who is highly respected in the area. I asked for a smooth finish and when I got home to see it today, it looks pretty good with the exception of a few spots that are white powder looking and still show float or power trowel marks. My question is what can I do to clean this up and smooth out this spot as well as around the edges where the trowel didnt get and is still a little rough looking. The price was good and I cant really complain but I would like to do something about it myself. I plan on Rustoleum Pro Epoxy for the floor and I want it to look good. Will these marks even show once the epoxy is applied?

 

[groove grabber]

If I remember right, it was the last place standing in water. What does that mean? I put a little sand paper to it and it seems to crumble off and gets fairly smooth. It is a little rougher than the rest though. It just looks like a big white powdery spot in the middle of the dark black polished concrete.

 

[groove grabber]

I just went and looked at it again and you can see where the power trowel kinda slung some of it around and onto the polished part. Could it be sheen water that he didnt let soak back in and he attempted to trowel it but then stopped. It has left a sort of finish like in the corners where the trowel couldnt get. Will this affect anything with me Rustoleum pro epoxying the floor here in about a month.


OR is there another exoxy that would work better with this

 

[groove grabber]

here are a few

 

[Mlynch]

hmmm... to be honest the smooth finish was counter productive to putting a coating on the floor. You will actually want to sand or grind the floor first to creat some profile and open up the pours of the concrete for decent adhesion. To be honest the sanding process will take care of the light colored areas they will sand right off.

Either rent a janitorial type low speed machine (also called floor buffer by some) with about a 30 grit sanding disk on the bottom or sub a contractor to come in w/ diamond grinders to rough it up before you coat it. This is the most important part of the job.

Where are you located?

 

[Nebraska Concrete]

I’m guessing that you go through seasonal changes where you live. Be it the case -your concrete will eventually begin splintering in short due time, especially without releasing the pressure put on the concrete after winter, spring and summer come around again.

Just a thought.

 

[WolverineCoatings]

OR is there another exoxy that would work better with this

Yes! I would suggest using a product (100% Solids) that does not contain ANY water or ANY solvent. If you want to hide the rough spots and have a monolithic smooth surface you're going to need to apply something thick. Solvented products can not be applied thick because the solvents will get trapped prior to evaporation. Trapped solvents will cause extreme yellowing and eventually a loss of adhesion. Multiple thin coats won't work because each coat will just follow the surface of the substrate. (It will build the high spots and the low spots in proportion) The liquid must be able to reach a level above the surface of the high spots while maintaining less than the maximum thickness that can be applied in a single coat. In other words, if the coating can only be applied at 8-10 mils per coat then you have to hope that your lowest valley is less than 10 mils. This is accomplished with 100% solids materials.

 

[Nebraska Concrete]

Lets see if I can make sense of this in a positive constructive manner.

It would be best to respect Mother Nature by giving this floor the chance to expand and contract over the ensuing years to come… (How many paint shops apply a color coating before they primer metal first?).

“Cut in the Expansion Joints” is definitely the #1 rule for this guys cement floor, (anything else is a shortcut that is overlooked). If you are worried about the crud that will build into the saw cuts, I would suggest you have a contractor prep the joints with specialty fillers. Specialty fillers on the cheap side mean that you are creating a barrier for water intrusion and debris from building within the joints while making it easier to wash out without releasing water underneath the concrete… (Specialized Epoxies do not make for great specialty fillers in the long run)…. They make it easier for the contractor to spend less money and get the job done quickly.

Apply a Great base coat through a trusted contractor before moving on to Epoxies. Great base coats create much better adhesion to the cement and in turn create much better adhesion to the Epoxies (equaling longer lasting coatings). Well worth the time spent I would think.

Well, an Omaha Home Builder just called me for a Brown and Black Chip Decorative Coating for one of their Garages…. You can bet on it that it will have a Great base coat before moving onto anything else.

 

[thegarageguy]

I agree with Nebraska concrete. Wait for a good freeze-thanw cycle. y that time your slab should be done settling and crack will be done growing. Then find a reputable flooring contractor.

By the floor pics, it looks like a sealer was attempted to be applied. Its not a problem, it just needs to be removed either by diamond grindeing or shotblasting.

Dont worry, Ive coated much worse slabs. A good floor guy would make it beautiful.