Why does my Granite show white powdery streaks after applying sealer?


I am using Mapei Ultracare 5-Sides Sealer over new installed Red Ruby Flamed Granite but after couple of hours a dry, white powdery streaks & patchy spots are appeared on the top Kindly advise why it happened ; what are the reasons and how I can strip the sealer off


ANSWER - First of all the data sheet for Mapei Ultracare says not to install it on the surface of the tile.  It sounds like that is what you did.

I'm not sure why it can't be installed over the face of the tile as that is typically what you do with sealers.

This sealer is designed to be applied to the edges and back of the tile to help prevent the tile from being subjected to underlying moisture.  I'm not a fan of applying a sealer to the back or edges of at tile, as historically sealers act as bond breakers and can compromise the bond of the adhesive to the tile.  I have seen other products where they say that sealer will diminish the bond strength of the adhesive, but if you use a high strength adhesive it is ok.  The Mapei product doesn't have a requirement.  They say it won't affect the bonding of the tile.  I have seen cases where it didn't bond well and cases where it did.

Generally speaking when you see cloudy white staining after applying a sealer it is because there was moisture in the stone and it has become trapped.

As far as removing the sealer, you should call Mapei and ask them how to do that.  Generally speaking there are strippers that are highly alkaline that can break down sealers.  Make sure whatever you use that you do a small test first to make sure it is working to your satisfaction.

Leave a Reply

Your email address will not be published. Required fields are marked *