Considerations Before Concrete Floor Resurfacer Preparation Begins

“How do I gauge the thickness of coating required after the floor is shot blasted?

I understand that the grooves from floor preparation need to be filled and that I must then determine how much material to put on top of the floor.

How do I compute the material needed to fill the grooves and level the floor? Some of the plant needs a lot removed from the surface; other areas are going to be coated after a slight brush blasting.

What are the rules of usage that generally apply regarding material needs when applying resinous floors in these instances?”

Well, general rule of thumb, forget about the shot blasting lines. But just talk about pre patching deviations, general rule of thumb is you have to pre patch any deviations that are greater than half the depth of the coating you’re going to put on top of it.

So, if I am putting down a one-eighth inch thick double-broadcast floor, and it’s eighth of an inch think, I need to pre patch any deviation in the floor greater than a sixteenth of an inch.

Now, when you think about thin film coatings, you almost have to take care of everything. That’s why brush blast lines even show through.

There’s two ways to take care of it: You can shot blast first, and then come at it with a diamond grinder. It all comes down to what you’re willing to pay for. There really is no hard and fast rule.

I can basically walk a floor, and estimate in my mind…say I’m doing an eighth inch broadcast floor. If I walk the floor, I can determine that 20 percent of this floor needs to be pre patched. And then visually conclude the depth at an eighth of an inch.

So that would be a pretty aggressive problem, actually. If I had to fill an eighth inch over 20 percent of the floor that makes a 1,000 square foot floor at an eighth of an inch, which means it’s more like a 1,200 square foot floor as far as my materials go.

On a thin film job, you have to decide at what point in time you change your prep method, versus adding more material. Again, this is the type of thing I could go on for hours about. I just had a guy on the phone talking about a job.

There’s 15 different ways to do the job. It really comes down to “What do you want to do?” I could just keep on throwing out more options, and more options, and more options about how to do something. What do you want to do, and how much money do you have to spend, and how much time do you have?

If the question is, “I know we have to prep the floor, I don’t want to see any blast lines, how do I take care of it?” Number one, you add an additional coat or you change your prep method. Number two – you add additional material.

If there’s a blast line problem, where it’s row, after row, after row, you’re not even at that point in time looking at a percentage of the floor. You’re literally just putting a whole other coat on the floor at whatever mils.

We’ve done it with a couple customers where we just changed the primer. We went from a 3-mil primer to a 12-mil primer. We picked up the extra mil thickness without incurring an additional labor cost. 

Also on another installation, we switched it from a 16-mil epoxy coating to a 27-mil epoxy coating. The facility guy didn’t want to add any more labor. He wanted a two-coat system for timing issues but didn’t wasn to see any blast lines.

Some of the cement was new; some of the cement was old. And we wanted to make it all look the same. So we switched it from 3-mil of the primer and 16 mils of epoxy, equaling 19 mils total, to 12 mils of primer and 27 mils of epoxy coating totaling 39 mils. We went from 19 mils to 39 mils, with no additional labor.

Again, it comes down to looking at what you want, and then figuring out how to get there. It’s just hard for a lot of facility people, because they don’t have the experience or the know how. They have to be willing to ask the questions.

The problem is, at a certain point in time they don’t even know what questions to ask. One business owner said, “No sand. I don’t want any sand in it. No sand.” He wanted the floor to be perfectly smooth.

I went around, and around, and around to explain to him the smoothest floors that we can produce for you have the most sand in them. Because we have to make a batter which will fill all the nooks and crannies and it will push all the resins up to the top.  And it will be perfectly smooth. He could not figure that out.

So, the installers just laid all the liquid out, with no sand whatsoever. It ended up failing the next year. So then I had to re-explain the whole thing to him. We reprepped the floor, took out what was failing, cut it out, replaced it, and redid it.

So they actually bought the sand for the job. And of course I told the installer, “Well there’s your big mistake. You should have just gotten in your car and driven away.”

Sometimes it’s better off losing a day of work then losing a week’s work of labor a year later, and having to re-buy all of the materials again.