The Challenge: “I’ve only had this tile six months now and it looks horrible!” If you have been in the floor maintenance industry for any amount of time at all, you have heard this comment. If you haven’t, then you will - it’s only a matter of time. The term “horrible” is usually not referring to the tile, but is in reference to the dirty grout lines that surround the tile. The next two questions will usually be “How did it get this way?” and “How do I prevent it from happening again?” As a professional floor maintenance technician, you should be able to answer these basic questions.
Understanding the ceramic/clay category is highly important to developing appropriate floor maintenance programs for them. This category of floor coverings is a juxtaposed category which consists of two primary components. First is the durable ceramic tile (porcelain, ceramic, quarry, terra-cotta, and brick) and second is the grout (non-sanded, sanded and epoxy) that holds it in place. It is this dichotomy that creates the challenges associated with the maintenance of ceramic/clay flooring materials.
Ceramic/clay flooring has been around for millennia, indeed they were one of the first products used as flooring as can be attested by the many mosaic floors scattered throughout the world in buildings of antiquity. The raw materials used and the production of ceramic flooring, although changed by technology, has not changed in process. Raw materials such as clays, feldspars, sands, dolomite, quartz and other natural minerals are used in the manufacture of ceramic products. These raw materials are combined and either dust pressed or extruded into their tile shapes. A glaze may or may not be applied to the tile and then the tile is fired at extremely high temperatures for a specified amount of time that is adaptable to the individual tile classifications.
This process results in products that are extremely durable and water resistant. Ceramic tile hardness ratings range from 1-5 with a rating of 1 being the poorest and 5 being the most durable. Most commercial flooring applications have a ceramic tile rating of 5. The ceramic tiles permeability to water is measured by using ANSI standards that measure water absorption of the tile. There are four ratings based on porosity and allowable moisture permeation; non-vitreous (>7%), Semi-vitreous (>3-7%), Vitreous (>0.5-3%) and Impervious (0-0.5%). The classification of the tile (terra-cotta, brick, ceramic or porcelain) will be directly related to the water rating and generally range from semi-vitreous to impervious. This combination of durability and water resistance is why ceramic/clay floors are used in kitchens, bathrooms, restaurants, malls and other high-traffic environments. It is also why most ceramic/clay flooring materials do not need floor finish to protect them.
The other side of the equation is the grout lines, which can be sanded, non-sanded or epoxy. Generally speaking most ceramic/clay floors are embedded in a sanded cementitious grout, but occasionally you will run into non-sanded or epoxy. The properties of sanded grout are the polar opposite of the tile. Where tiles are generally very smooth and hard (even though they sometimes have a texture), sanded grout is irregular and porous. To compound this, the grout lines are usually lower than the surface of the tiles, which is one of the reasons that maintenance of ceramic/clay flooring can be so difficult.
Cause and Effect
The soiling of grout lines does not generally happen overnight, it is a process that builds up over time. The amount of time it takes to soil grout lines can be quick or over a long period of time and is a direct reflection of the maintenance program in place. Initial maintenance for grout is usually done by the installer and consists of cleaning the grout off of the surface of the tile and sealing it with a penetrating sealer or impregnator. If this is done at the offset, then the grout lines have a much better chance of repelling moisture and soil right out of the gate.
The biggest issue with ceramic/clay flooring is in the daily/routine maintenance - specifically the wet mopping service procedures. There are five mopping procedures; spot, damp, wet, wet with rinse and aggressive. Each of these mopping techniques is comprised of applying solution, agitation, removal of contaminated solution, rinse and damp mop. What usually happens is the janitor, custodian or in-house employee mops the floor on a daily or routine basis by submerging the mop into a bucket of cleaning solution and mopping a section of the floor or room. They then repeat the process until the entire area or room is complete. In the case of microfiber flat mop systems, they essentially do the same thing only they change the microfiber applicator at each break instead of re-submerging the mop in cleaning solution, which is better in the sense that you are at least using a clean microfiber on each pass.
The problem is this: When you use a one-pass system, you are not removing the soil - you are only moving it from one place to another. Also, cleaning solution is left on the floor (especially microfiber application), which ultimately leads to the surfactant build-up becoming a soil attractant causing tacky floor syndrome. With the exception of spot mopping and damp mopping, which can be accomplished in one pass, all the rest will require a minimum of two passes and in some cases three or four, depending on the soiling condition. Correct mopping procedures are imperative to a successful ceramic/clay category floor maintenance program.
The effect is that every time the floor is wet-mopped, the soil is lifted off the floor and suspended in the solution. If it is not removed with a rinse mop or vacuum, it will settle right back down on the floor surface. To make it even worse, the contaminated solution seeks the path of least resistance and goes to the lowest point, which just so happens to be the porous grout line, and deposits soil and surfactant in the most difficult place to remove it from. Time and incorrect wet mopping causes soil to build up to where the grout lines turn black. Keep in mind that a mop is nothing more than a rag on a stick and if you don’t keep your mops clean, you will ultimately have a dirty rag on a stick, which will only contribute to soiling the floor more.
A method for reducing - and in some cases eliminating - this problem is in a periodic cleaning of the ceramic/clay floor using one of three methods. The best method is using a pressurized spinning tool attached to a truckmount or portable hot water extractor. This method blows the soil out of the low areas up into the shroud for evacuation by the extractor. The next-best method is to use a cylindrical brush machine with counter rotating brushes to agitate the surface and pull the soil up to the surface to be evacuated with a wet floor vacuum. Another method incorporates using a rotary floor machine and a brush to agitate the surface followed by extraction of contaminated soil with a wet floor vacuum. Using either of the last two methods will still require a fresh water rinse after extraction.
The ceramic/clay category of flooring may be challenging for the floor maintenance technician, but if proper daily/routine mopping techniques are used, the soiling conditions of the grout lines will improve. Before the grout lines succumb to heavy soiling and become black, incorporate one of the periodic service procedures to improve appearances. You do not want to get to the point where a restorative process will be needed, because that’s another story altogether.