Q.we just finished tiling our new shower .do we have to seal the shower walls and floor?we used polished calcutta gold 1x1 mosaicon the floor and 12x12 on walls.we were told by the vendor that we should seal the tiles.is it necessary to seal polished calcutta marble?thanks,mira

A. Hi Mira,
The only thing that an impregnator(sealer) does is dramatically reduce the natural absorbency rate of the stone by filling in the spaces between the single minerals composing the stone. These spaces are known as pores - End of the list of performances.
This reduction in absorbency rate (or porosity) of the stone will make it possible that staining agents which get spilled on the stone will be kept at bay, on the surface of the stone, for a period of time much longer than if the stone was not sealed.

Most polished marbles have a lower absorbency rate as the finish closes the pores somewhat but should always be

 tested using the water test. (a palm sized puddle of water to sit on the stone for five minutes or so and then wiped away. If it leaves a darker mark then you know your stone is absorbant and needs to be sealed.

While calacutta may need to be sealed in a kitchen area or vanity I am not sure it will be of any use in the shower.

The walls are a vertical surface that will probably never have anything on it long enough to stain it. The floor if installed correctly will slope to the drain.

If it makes you feel better sealing probably wouldnt hurt it

and our mb-4 is a great product and easy to use.
Of course what they didnt tell you was that most polished marble will become honed or matte over a period of time

within the shower stall. It can be refinished again by a pro but it isnt a cheap project. The other issue is to be aware that any acidic products will etch the stone (leaving a dull mark sometimes refered to as water makes but not at all caused by water. If we can ever be of any assistance please feel free to visit our websites or call us at 888-400-4302.

Stu Rosen