The Problems with Cross-Hatching/Cutting Concrete

This article is based on an episode of the WORX+ TechTalk series. You can watch the full episode here.

Though cross-hatching (also known as cross-cutting) may seem like a good idea, ultimately, it creates more problems than it solves.

Cross-hatching involves grinding the floor in one direction with a particular grit, then grinding the floor again in a different direction, either with the same grit or the next grit up. In Australia, cross-hatching is becoming less and less common, yet the WORX+ team still get asked about it. Our recommendation is that it shouldn’t be done. Josh says the only reason you’d do cross-hatching is if you don’t want your floor to be flat or “if you want more ripples”.

Let’s explore why.

THE PROBLEMS WITH CROSS-HATCHING

Time Wastage: cross-hatching doesn’t make the floor any flatter or expose any more aggregate, so contractors that employ this technique are ultimately spending more time and money to cross-hatch and achieving the same result.
Impairs Flatness: this technique can cause the machine to go up and down over ridges in the concrete floor, which does the opposite of making the floor flat like we want.
Reduces Tooling Performance: cross-hatching exposes more aggregate in the concrete and reduces the effectiveness of the grits.
Harder to Remove Ridges and Scratches: in later passes, the impaired diamond tooling from the previous pass will create a smoother texture, which will be harder for the next grit to cut.
Confusion: cross-hatching is confusing because it requires contractors to keep track of which direction they have ground the floor. In this situation it is easy to lose track and create inconsistencies.

Josh has a solution if you’re cross-hatching and you’re confused.
“This is... this is breaking news. We've got um a new product coming out. It's a compass for your grinder. Just so you know which way you're going.”

He’s just joking (as always).

THE BEST TECHNIQUE

So, if cross-hatching isn’t the technique to go for, what is?

The simplest process is best: you should be grinding your floor in one direction with the appropriate amount of overlap and machine speed. After the first pass with a 30-grit, the concrete will be rough, but this is normal, and you should be able to see all the aggregate you want in the finished product. You can determine the right wheel speed by monitoring what is coming out of the back of the machine.

KEY TAKEAWAYS

The WORX+ team are against cross-hatching, but that doesn’t mean you should blindly follow the method listed above. At each stage, it is important for contractors to pay attention to the floor's appearance and adjust accordingly. 

Part of our mission here at WORX+ is to help you feel you feel totally confident in your concrete grinding and polishing results. Our team are the best in the business, so let us help you find a method that totally WORX - give us a call on 1300 897 873.

Hang on, we’ve got more for you!

Check out our other TechTalk articles below, where we address common issues contractors face and the nitty gritty of the concrete grinding and polishing industry.