Coating over tiles is often requested for both homes and businesses, especially in kitchens, bathrooms, shops, and renovations where removing tiles is not practical. Epoxy and resin systems can work well on tiles, but success depends on proper preparation.
This article guides applicators through the correct process for coating over tiled surfaces, detailing proper surface preparation, grout line management, and correct priming techniques to achieve a smooth, level, professional finish using APC epoxy systems.
Can You Epoxy Coat Over Tiles?
Yes, tiles can be coated successfully if they are structurally sound, well-bonded to the substrate, and properly mechanically prepared.
Tiles are non-porous and often glazed, so epoxy coatings will not stick properly unless the surface is prepared first. Grout lines also create uneven areas that must be levelled to prevent shadowing through the finished coating.
Coating over tiles requires a different approach than coating over concrete. Tiles are non-porous, often glazed, and include grout lines that create height variations across the surface. Without proper preparation, these factors can cause poor adhesion, visible shadowing, and uneven finishes.
The following steps outline a proven method for coating tiles with APC epoxy systems. This process helps applicators achieve a flat, uniform surface that is ready for priming and system build-up.
Step 1: Surface Preparation for Coating Over Tiles
Grinding Tiles for Mechanical Adhesion
Grinding is the first and most important step when coating tiles. The goal is to remove the glaze or any surface coatings, create a rough profile for the epoxy to stick, and level the tile and grout surface.
Remove the glaze or sealed surface from all tiles. Use softer bond diamond segments on tiles to maintain cutting efficiency. If grinding produces little dust or stops cutting, switch to a softer diamond immediately.
Use a hand grinder on edges and corners to keep the surface consistent.
Safety Considerations When Grinding Tiles
Grinding tiles presents safety risks that need to be considered. Tiles can fracture and chip unpredictably, often breaking away in sharp fragments that can be projected. Ensure the following to reduce the risk of injury:
- Eye protection is essential to shield against tile shards and dust that can be ejected from the grinder.
- Gloves help protect hands from sharp edges when handling tools and broken tile fragments.
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Wear long sleeves and long pants to protect yourself from flying debris, especially when grinding edges, corners, or uneven tiles that may chip.
- Wear steel-capped boots to protect your feet from tile fragments and sharp debris, which increase when grinding tiles.
Step 2: Repairing Chipped or Damaged Tiles
Tile chipping can occur during grinding and must be repaired before moving forward.
How to repair chipped tiles before coating
- Mix epoxy with sand to a wet, workable consistency.
- The mix should look like wet sand and lightly self-level.
- Use a trowel or spatula to fill only the chips and voids.
This step is not for levelling the floor. Its purpose is to repair damage, so defects do not show through the coating.
Step 3: Filling Grout Lines When Coating Over Tiles
Grout lines are the main reason tile patterns can show through epoxy floors. If not properly filled and flattened, they will appear through the primer, flake, and top coats.
Apply a ceramic screed coat to fill grout recesses, start flattening the tile surface, and create a more even substrate. Spread the screed thinly and press it firmly into the grout lines.
Step 4: Grind the Screed
After the screed coat cures, grind the surface. Make sure grout lines are flush with the tiles, there are no ridges or low spots, and the surface feels flat underfoot.
If grout lines are still visible, apply an additional scratch coat before priming.
Step 5: Apply a Ceramic Scratch Coat Over Tiles
Use a ceramic scratch coat if grout lines or tile patterns are still visible after the first screed and grinding. Its purpose is to remove remaining grout shadows and make the surface flat.
Apply the scratch coat thinly, pressing it into low areas. Once it cures, grind it back so the ceramic stays only in the grout lines and recesses.
Step 6: Priming Tiles Before Applying Epoxy Systems
Once you have a flat tiled surface with no visible grout lines, you can begin priming.
How to Prime a Tiled Surface
- Apply primer the same way you would on concrete.
- Roll it on evenly and watch your coverage.
- If grind marks are still visible, add a little more primer instead of over-rolling.
After the primer cures, lightly sand or Polivac the surface to remove roller texture, dust, or high spots. This creates a flatter surface for the decorative or protective coats.
Step 7: Final Inspection Before Building the System
Before applying Ultra Flake®, Hyper Flake®, or other APC Systems, inspect the surface. Applicators should confirm that grout lines are no longer visible, there is no tile pattern shadowing, and the surface texture is uniform.
If you spot any defects, fix them with an extra scratch coat or localised repairs. It’s much easier to correct issues at this stage than after the epoxy or topcoats are applied.
Applying APC Epoxy Over Tiles
Once you have primed and sanded the tiled floor, it will behave like any other prepared surface. You can then apply APC systems, such as Ultra Flake® or Hyper Flake®, following the standard application steps.
Q&A: Epoxy Coating Over Tiles
Yes, if you don’t fill and flatten them properly, grout lines can show through. Make sure you blend and hide grout lines using correct screeding, scratch coating, and grinding to prevent shadowing.
No, as long as your tiles are sound, firmly bonded, and properly prepared.
No. You must grind off the tile glazing to create a surface the epoxy can properly adhere to.
Apply as many coats as needed to remove grout lines and level the surface. Some floors may only need one coat, while others require multiple passes.
Yes. Priming ensures even absorption, hides grind marks and provides a consistent base for the next coats.
If you miss any grout lines, they can show through the final top coat, even after you apply flake or other decorative layers.
Key Takeaways For Epoxy Coating Over Tiles
Coating over tiles is achievable and reliable when preparation is done right. Grinding, repairing, screeding, scratch coating, and priming all play a role in producing a flat, professional finish that performs long-term.
Rushing preparation or skipping steps significantly increases the risk of defects and callbacks.
Need Technical Support for Applying Epoxy Over Tiles?
The APC technical team is here to support you every step of the way, from choosing the right system to preparing and applying your coating. Visit your nearest APC showroom or contact our team to ensure your tile overcoat project delivers smooth, consistent results from base coat to top coat.
Watch our Tech Talk video on YouTube where Matt from R&D shows how to perform all these steps.
Epoxy Over Tiles: A Guide for Applicators