Tile is one of the most common flooring options used in commercial kitchens. This is simply because it is easily accessible and cheap.
However, seamless resinous floors are becoming more popular than tile due to their anti-microbial and stain resistance qualities, as well as their slip-resistance and durability.
Tile Flooring Issues
The problem with tile floors is that they tend to crack and become loose over time. Additionally, grout lines are almost impossible to keep clean, they are very slippery when wet, and grout lines can harbor mold, mildew, and harmful bacteria.
These and other problems can be avoided by installing a urethane cement flooring system in place of quarry tile.
The Benefits of Urethane Cement
Urethane floors are steam-cleanable, moisture tolerant, and thermal shock resistant. As this flooring system becomes more popular, people have been wondering if it is possible to install urethane flooring over tile.
The good news is that it is possible to install urethane cement over tile, if done by an experienced resinous flooring expert.
How Is Urethane Cement Applied Over Tile?
Before doing any prep work, the contractor will first evaluate the tiles and determine if some tiles are coming loose or if they are shattered.
If this is the case, the tiles will need to be removed to reach the concrete substrate, as tiles not bonded to the concrete will cause the urethane topcoat to break apart.
A fantastic case study project involving a failing quarry tile that needed to be removed can be found here: Commercial Kitchen Floor Installation & Waterproofing. Assuming the tiles are mostly still in place, your contractor will then proceed with surface preparation.
Applying The Urethane Concrete
The primary concern with applying urethane concrete on top of tile is adhesion. In order to ensure proper adhesion, it is important to treat the surface and prepare the tiles.
There are two ways to prepare the tiles; micro-etching and grinding.
To micro-etch you will need an acid-based etcher. While micro-etching can be cheaper and easier to perform, the uniformity of the etching is suspect and the acid can actually slip underneath the tiles and loosen them.
If multiple areas of the surface are not tested for porosity and texture, the coating can potentially fail in those areas. Grinding may be the more labor intensive and expensive option, but the results are much more uniform and consistent.
Removing The Tiles
If the grinder shakes some of the tiles loose, it may be a sign that you will need to completely remove them. With some hard, non-porous tiles, grinding may not be enough and an additional specialty primer is needed.
If the tiles are glossy or have a sealer, then a grinder is a necessity, as hydrophobic properties of the tile coating will prevent adhesion.
If you want to learn more about the surface preparation methods discussed, and specifically the grinding process for tile floors, check out this resinous flooring installation case study of Kenilworth Hotel Kitchen.
Challenges Grout Can Present
Beside the tile itself, grout can also present its own set of challenges. Grout is a porous material, which over time can soak up many foreign substances, such as oil and grease, that can ruin the resin adhesion.
In most commercial kitchen flooring you will want to completely remove the grout, but if it is isolated to small areas you may just want to remove individual occurrences.
Once the tile and grout are treated, a flat substrate will need to be created by either grinding the tiles flat or applying a leveling compound. Typically a leveling compound is used, as it is quicker and easier, although it can be more expensive.
Choosing The Correct Leveling Compound
Not all leveling compounds are the same. Some are heavily diluted with water and can form a very porous surface that can lead to bubbles and variations in gloss. Other levelers can expand and contract at different rates than the tiled floor, which can lead to grout lines becoming visible.
These grout lines may not appear immediately after installation, so it is imperative you have an experienced resinous flooring expert evaluate the floors.
This is especially true if you are using metallic pigments, as they typically flow and settle freely in low-viscosity resins and are excellent at finding any low spots. Even if you can’t feel the grout lines anymore you can still end up with a visible grid pattern.
Premature Failure of Urethane Cement
Premature failure of some urethane cement floor installations has prompted many who initially saw the advantages of seamless flooring to return to tile. Despite this, commercial kitchens have more to benefit from resinous flooring than any other industry.
Urethane cement floors are designed to withstand the type of high traffic, high temperature, slippery, and messy conditions that commercial kitchens present. While applying it over tile is not always possible, it can be done in most cases.
It is important to find a trusted resinous flooring expert who can properly evaluate the condition of your tiles, prior to installing a urethane cement floor. To learn more about flooring options and regulations for the food and beverage industry, check out our blogs “What resin flooring options are available for the food and beverage industry?” and “FSMA Act – What you need to know”.