I recieved some free polyurethane/alkyd based floor paint and painted my garage floor (used as a woodworking shop).

I did not pre-treat it in any way, just cleaned it. The workshop is relatively new (2014) and the floor was just screed flat (really well done job though).

From what I've come to understand you should grind the floor first, or acid etch it.

How big a miss is this on my part, is my floor going to peel off very easily, or is it mostly a looks question?

I don't need a perfectly flat and shiny floor, just want a brighter color that is easier to sweep clean.

  • Concrete paints just fine. Treatments are highly over-rated. If the concrete is fresh, just paint. Otherwise vacuum it well with a new brush (old brush may be greasy and you do not want to spread grease over concrete to be painted).
    – ajeh
    Aug 9, 2017 at 14:19
  • Acid etch is needed if the concrete is dirty, a clean fresh slab even several years old would have no problems, after the new slab is fully cured I don't etch but a older slab with a few oil stains I 100% etch with muratic acid solution the dirtier the higher % of acid, don't forget to always add acid to water, the other way around can have bad results (chemically, exothermic)
    – Ed Beal
    Nov 23, 2017 at 4:33

3 Answers 3


The point of the sanding or etching is to encourage adhesion by removing contaminants and roughing up the surface to give the paint something to stick to. You may or may not have problems - hopefully you won't but if you do you'll know what to do before you repaint.

  • 1
    It's holding up pretty well so far, it has flaked somewhere but dragging heavy cast iron machinery can do that... It's a great improvement in my shop, sweeping up dust and shavings and it brightened up the whole place. Here's a recentish view of the shop c2.staticflickr.com/6/5604/30182263224_8d1f9d9798_b.jpg
    – Dennis
    Dec 29, 2016 at 8:37
  • Concrete is very spongy as it is. I would not waste time and money on any sanding or brushing, unless the surface is rough and esthetics is important.
    – ajeh
    Aug 9, 2017 at 14:21

It's 2023 now and I painted this floor in 2016. I figured I could post a photo of the floor from this year, when I cleaned out most of my woodworking machinery to move it to another building. The paint has held up pretty well. Some has flaked off but it's over 99% intact. enter image description here


I would have recommended cleaning the concrete well first, removing all dust and dirt. I would recommend asking the hardware or paint department about applying a primer to the concrete before painting. I know if you want to paint the floor with acid that is a finish process of its own that looks beautiful. You can do it in different colors too. I have done a lot of research online about floor paint and sealers. I also spoke with paint specialists, contacted some companies and asked end users about their experiences with floor paint. It seems to me there are a few products that work best on concrete floors. They seem to be more durable and lasting for high wear. In all my research I have never come across anything that suggested grinding the floor first before painting it. I wouldn't give up on your floor yet.I thinks your floor will last and even if some of the paint comes off, I bet it lasts a while. Who knows, maybe it will last a few years. Good luck,

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