Pin holes (sometimes called “bug holes”) in concrete are more than just unattractive surface voids, they can lead to cracks, gouges, and other issues that weaken your slab, reducing its lifespan and increasing then need for costly repairs. For coated surfaces, pinholes and pits lead to faster wear and unattractive peeling.

Pinholes and surface voids need to be repaired during the surface preparation process to prevent worsening problems later on, and one of the best solutions to fill voids is by grouting your concrete. To learn how to grout your concrete surface, check out our video below or read on to learn more.

Choosing the Right Concrete Grout

When filling the voids, we are often asked about using concrete dust as a grout material. Many professionals will simply take their dust collection bag and recycle what is in it as a cost-effective solution.

While this can work, we don’t recommend using your concrete dust as a grout. When you open the bag, you’ll feel dust, but you’ll also feel and see contaminants – dirt, paint chips or old epoxy, concrete chunks that didn’t get broken down – anything that got picked up by your vacuum is in that bag. It’s not a consistent material, and there’s no way to truly ensure quality control for what you’re putting back into this floor. Even filtering this dust, it can lead to problems down the road. 

Instead, we recommend marble flour, a graded, dry substance that is highly refined and consistent. Most important to us, it’s free of contaminants and is the same quality from bag to bag. While you have to order it, unlike concrete dust that’s right there, it’s inexpensive, and it’s worth knowing you’re putting down a quality product on your floor.

Installing Grout to a Concrete Floor

Adding a grout coat over an open concrete floor is a fairly quick process, depending on the space. While the floor is still wet from an epoxy coat, we apply the marble flour to the floor, then use EG grout pans on a Prep/Master floor grinder. Using these concave grinders, the air is pressed out of the pinhole and the grout is pushed in its place. 

In small spaces, we can simply use these grout pans by hand, similarly to hand troweling. However, these are designed to be used with a floor grinder to save time while extending the life and appearance of your floors! 

Contact Us for Concrete Grouting Materials

We know how important it is to get the job done right the first time, and that’s why we have all the tools necessary for successful surface preparation. From efficient, powerful floor grinders and grout pans to epoxy coatings, we have what you need. To learn more about our selection and accessories, and get the best possible price, speak with a product expert today by calling  815-472-9754.