Putting the Finish to Ceramic Floors
July 21, 2010
Ceramic flooring constitutes a significant amount of hard surface flooring sales, and a bit more than 11% of all new flooring materials sold overall.
Tough and durable, ceramic and porcelain tiles are capable of taking on the heavy traffic of shopping malls and transportation environments, as well as giving a touch of class to any commercial or residential locale.
One of the most common uses of ceramic tile is in the restroom, and one of the most frequently asked questions I get concerns the application of floor sealers and/or finishes on ceramic in the restroom environment.
I have had individuals argue adamantly for and against the practice, and I am quite sure the argument will never end. The decision is ultimately up to the facility owner and the maintenance professional, and should be evaluated thoroughly.
Before committing to the application of floor seals and/or finishes, it’s important to understand the properties and characteristics of ceramic/clay flooring materials.
Ceramic/clay floors are divided into moisture ratings. These ratings represent the amount of moisture that the body of the flooring material will absorb.
- A non-vitreous tile will absorb 7% or more moisture and is non-frost resistant.
- A semi-vitreous tile will absorb 3% - 7% moisture and is non-frost resistant.
- Vitreous tiles absorb between 3% and 5% moisture and are frost-resistant.
- Impervious tiles will absorb 0% to .05% moisture and are also frost-resistant.
Most ceramic flooring used in restrooms are of impervious type, therefore moisture will have a hard time penetrating into the surface. This is the primary reason for their popularity in the restroom environment.
The downside is that all ceramic tiles are surrounded by sanded grout of varying widths. The grout is extremely porous and allows moisture to penetrate easily, which is just the opposite of the ceramic tile. This is why the grout should be sealed with an impregnating or penetrating sealer after installation. In some cases, additives such as latex are included in the grout matrix, which seals the grout during the installation process.
Either way the grout will be protected after installation and will not require water-based acrylic floor seals or finishes applied to them. The system that is already in place will be sufficient to meet the conditions. With proper maintenance these floors are capable of lasting a very long time.
Although ceramic tile floors in restrooms really don’t require floor finishes, there are many instances of acrylic polishes and in some cases urethane coatings being used on them.
One line of thought is that by applying additional floor finish to the ceramic tile, you reduce the amount of urine, germs and bacteria that can penetrate into the surface of the tile and particularly the grout.
Additionally, older ceramic tiles may start dulling out, in which case an owner or manager might want to incorporate the application of floor finish to bring the appearance level up to a more acceptable level and to protect the floor against additional erosion.
When floor finish is applied to ceramic tile in the restroom, issues may occur quickly or over a long period of time. The results of trying to get floor finish to adhere to glazed ceramic or porcelain tile can be immensely frustrating.
The surfaces of some of these products are so smooth that the floor finish will not stick to it. When floor finish is applied it will usually dry fine, then start peeling off or powdering off shortly after application.
Floor finish has better adhesion on unglazed ceramic tile, and can actually last for a very long time. There are lots of ceramic tile floors maintained with floor finish in much the same manner as one would maintain VCT.
Maintained correctly, these floors can look excellent and protect the floor, but over a long period of time, as the floor is subjected to the effects of erosion and periodic and restorative maintenance methods, they will become unsightly.
Finish on a ceramic tile will erode in the same manner as finish on any floor. Micro scratches ultimately dull the floor which can be repaired with scrub and recoat service procedures to bring the gloss back.
The periodic service procedure is performed several times before the restorative service procedure may be required. The strip-and-refinish service procedure will be incorporated when the time comes to remove all preexisting coats of seal and/or finish.
When the strip-and-refinish procedure is performed, the emulsified floor finish and soil has the potential of getting lodged in the porous grout if the floor is not properly rinsed. Embedded soil wedged into the pores of the grout often gets floor finish applied over it, compounding the situation so that the embedded soil is now encapsulated soil.
Over many strip cycles, the soil and finish penetrate deeper and deeper into the grout until the only way to remove it is to remove the effected grout with the soil and finish. In many cases the encapsulation is so deep, the only solution is to cover the grout with special colorized grout seal or re-grouting.
There are a number of specialized grout systems available from different companies to combat this situation.
Ceramic tile in restrooms is a challenge in any building and the methodology that one maintains the floor is diverse. Although the ceramic tiles and grout do not require floor finish, the floor maintenance technician will always find themselves in the precarious position of having to maintain ceramic floors with floor finish on them or not.
The professional will have an answer for both situations.