Urethane Cement Flooring For Tiles
Updated: Feb 7
Tile is one of the most common floors used in commercial kitchens simply because it is easily accessible and cheap but increasingly seamless resinous floors are overtaking tile due to their anti-microbial, stain resistance, ease of maintenance, slip resistance, and durability.
The problem with tiled floors is they tend to crack and come loose, grout lines are near impossible to keep clean, and are very slippery when wet. In particular the 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. Also called “urethane mortar” or “urethane concrete”, cementitious urethane floors can be installed with an integral cove base and proper slope to drain.
These floors are also steam-cleanable, moisture tolerant, and thermal shock resistant. As they become more and more popular I hear the question “Can you have a urethane floor over tile?” The simple answer is absolutely if done by an experienced resinous flooring expert. So how is it applied over tile?
Before doing any prep work the contractor will first want to evaluate the tiles. Are some coming loose or shattered? If this is the case the tile will need to be removed to reach the concrete substrate as tiles not bonded to the concrete will, eventually, 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 then you can proceed with surface preparation.
The primary concern with applying urethane concrete on top of tile is adhesion. The key is in the surface treatment and 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 get underneath the tiles and loosen them.
If multiple areas of the surface are not tested for porosity and texture, then you run the chance of having areas of your coating fail. Grinding may be the more labor intensive and expensive option but the results are much more uniform and consistent.
If the grinder shakes some of the tiles loose then it may be a sign that you will need to completely remove them to get to the concrete. With some hard, non-porous tiles, like vitrified 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.
Beside the tile itself, the grout can also present its own set of challenges. Grout is porous material so over time is soaks up all sorts of foreign substances, like oil and grease, that can ruin the resin adhesion. In most commercial kitchen floorings, 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. Let it be known, 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, while some levelers can expand and contract at different rates than the tiled floor and lead to grout lines becoming visible once again. The grout lines may not appear for a long time after installation which is why it is imperative you have an experience resinous flooring expert.
This is especially true if you are using metallic pigments as they typically flow and settle freely in low-viscosity resins and consequently 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 some installations has prompted many who initially saw the advantages of seamless flooring to return tile. The shame is that commercial kitchens have more to benefit from resinous flooring than any other industry.
Urethane cement floors are designed to withstand the the kind of high traffic, high temperature, slippery, and messy conditions that commercial kitchens present. While applying it over tile is not always possible, it can absolutely be done in most cases.
The key is to make sure you find a trusted resinous flooring expert who can properly evaluate the condition of your tiles. 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".