porcelain tile finish

[sgull]

At my workplace we have some good commercial grade unglazed porcelain tile installed for the lobby floor. I don't know the manufacturer, nor does anyone else. In storage we have a small stack of left-over tiles from the installation, and upon inspecting the backside of the tiles it says "made in Italy" and "Gres Porecellano". Nobody knows whether the tile floor was ever actually sealed with a sealant, it might have been years ago but like I said nobody knows. Recently by mistake a worker applied some floor finish not necessarily formulated to be used as a finish for this type of flooring material. So we are in the process of stripping the stuff off (with some floor stripper solution), as it's kinda flaking off anyway. After we get it stripped, we were wondering what exactly is a recommended product to apply which would "seal" it (if that's necessary) and which would make the floor glossy/shiny like wet look. The tile is actually is actually a rather matte finish by itself, so if we want it glossy would a glossy sealer/finish work? Thanks for any comments/suggestions.

[JazMan]

Most people mistake the word "glazed" to mean shiny. Glazed does not = shiny. Your tile is probably glazed, it's just a matte glaze. You want shinny? Re tile the floor with shiny tiles, but be prepared for more maintenance and possible slip & falls if it's close to an outdoor entry.

Jaz

[sgull]

Jaz,
After doing a little more reading about the differences between glazed and unglazed porcelain tiles, I'll agree with you that our tile is probably glazed and not unglazed as I had previously assumed. My initial assumption that they're unglazed was not that they aren't shiny but was based on these statements I came across:
(1) "With a glazed tile, the surface of the tile is often a different color than the body of the tile. When wear occurs on the surface of a glazed tile, it can wear away the glaze so that the different color in the body of the tile shows through."
(2) "Unglazed [aka, 'color through', color body', 'solid body', 'through body'] has the pigments evenly distributed throughout the tile [though the face still tends to be darker]."

Our tiles definitely seem to have the same color/pigments evenly distributed throughout the tile and not any different looking on the surface, that's why I thought they must be unglazed. But apparently, from what I understand now, the color in a glazed tile can go all the way through also. I can see now that it makes sense that we should have the matte glaze tiles in our lobby, with the nearby outdoor entry and a lot of people walking in from outside. We thought glossy might somehow spiff it up to look not so dull. But no, we definitely don't want more maintenance and of course don't want to increase the likelihood of slips and falls by making it shiny/slippery. The matte will be just fine. Thanks for setting me straight about it. Once we get that wrong finish stripped off, would you recommend anything further be applied onto the glazed tile, or just leave it be?

[JazMan]

Let me add one thing about shiny and matte. Had your tile been shiny, it wouldn't necessarily mean it would be slippery under certain conditions. Chose one with a slight texture, and you're good.

Contrary to popular belief, glazed tiles, whether porcelain or regular quarry, can benefit from a penetrating sealer. Even glazed tiles have microscopic pores. Another shocker, sealing a glazed tile with certain penetrating sealers make the tiles less slippery. (I don't know why). Quote from Miracle Sealants;

All surfaces treated are harder and less slippery.

The main need to seal tiles is to seal the grout. I would seal all cement base grout regularly.

Jaz

[sgull]

Thanks. Looks as though the Miracle Sealant "511 Impregnator" penetrating sealant might be worth applying to our floor, as it apparently seals the grout as well as the tile surface. The quote "all surfaces are harder and less slippery" has me wondering about the "harder" part. Our floor already seems about at hard as it could get. So I'm just curious about whether it would actually make the floor any harder. Also, in the description/instructions it says this:
"Resealing will vary depending on porosity, density, hardness, foot traffic and the elements (indoor or outdoor) the area is exposed to. As a general rule, medium to dense surfaces exposed to heavy foot traffic can be resealed every 1 – 3 years. Very hard surfaces exposed to heavy foot traffic can be resealed every 3 – 5 years."

Again, in regard to "hardness" and "density" and "porosity" how can I really determine such our existing floor? How hard, dense, or porous is the glazed porcelain anyway? It seems, to me anyway, its pretty darn hard and dense, and I wouldnt say it seems very porous...

[JazMan]

Yea, the hardness part is difficult to understand. I'm sure it's true by testing, but it is irrelevant for porcelain tiles IMO. Density and porosity are easy to understand, but don't worry about it with porcelain.

Porcelain, by definition is very hard, dense & un porous with an water absorbency rating of under .5% of it's weight. I've seen some as dense as .060%.

511 Impregnator was the one I had in mind. (good job).

Jaz