porcelains are porus

[simmy08]

just tiled a bathroom floor with 600x300 black mineral quartz fully vits porcelains. These tiles are glazed and rough. Read in previous thread that when grouting these boys be quick to wash off as they are so rough. As ive sponged off excess addy i noticed they draw a little water so must be porous. I am quite confused as i know fully glazed are not porous. anyone had same issue? could they have some other coating on that gives a glazed look? even the sponge marks are quite apparent at the end of shift. wonder wether temporary sealing them would make a difference before i grout.???

[Dave]

Mineral quartz are a pressed through bodied glazed porcelain and will not accept a porcelain impregantor to aid in the cleaning process.

[simmy08]

Thanks dave, so when the tile is the same material all the way through it is a pressed bodied, i thought it was fully vitrified?! what does a fully vitrified and a normal porcelain look like?

[Dave]

Fully vitrified is just a tile that has been fired at high temperature so that is vitrifies which means glass like....All porcelain tiles are fully vitrified but some are glazed and some are through bodied...through bodied porcelains are the same colour from the face of the tile to the back and have no glaze on them , even polished porcelain is through bodied and none glazed porcelains need sealing to aid in the cleaning and maintenence of them.

A glazed porcelain bodied tile tends to have a seperate colour on the face of the tile just like ceramics but with the harder body ( porcelenato is one make is extemly hard but ) ..and will not except water or sealers just like standard tiles...

And by pressed i mean the pattern on the tile face is press finished into the body of the tile to create the pattern.This is how porcelain can mimic natural stones.

[smurf21]

All porcelain is vitrified glazed just has a diff firing procedure.

Porcelain Wall and Floor Tiles

[simmy08]

These are porcelanto,real hard. i look at the back of the tile and i compare it to the front. back is dull but same material as front...front face is a little darker as im certain some sort of glaze/laquer is on it. its not as matt finish as the back and is defo shinier. just confusing as it looks like some sort or glazing.

[Dave]

They are glazed...like i said ..but very hard...

[Dave]

I have used the mineral quartz a few times and they are hard to get clean if you leave it too long before washing off..

A grout haze remover will shift any stubborn bits,,

[simmy08]

yep, misread your reply. thanks will keep all that in mind

[365drills]

Our installed black porcelain tiles sound the same, its very textured and was also showing signs of absorbing water and holding grout on the surface. But on closer inspection it turned out that the tiles were coated with a waxy film which was mixing with the grout an holding the grout onto the tile surface.

To get rid of that problem all the tiles were cleaned with a sugar soap solution prior to grouting.



The Black Porcelain (Close Up - Above) Tile was VERY rough. Lots of places for grout to hide / stick



The tiles were part of a feature panel for a shower so they were not in large numbers. Took about 20mins to scrub them in preparation for grouting.

Andy (our tiler) added a bit of sealer to them prior to grouting to act as a barrier against the grout. He left me to grout them and I was able to just sponge off the excess. Any stubborn grout left in the little pits of the stone I got out with a domestic scouring sponge by a circular motion.

I think in contrast to natural tiles black tiles tend to "look" worse during installation because as the water dries out they highlight everything. As the tile dries it leaves an exaggerated white haze or smear. When I was left with a whitish smear or haze I had to pray that it would wipe off next day... It did!