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Flooring and Carpeting/Unglazed Porcelain Mosaic tile - Seal or clear epoxy paint?


My bathroom floor is 1/2" unglazed porcelain mosaic tile, 100+ years old. It looks perpetually dingy. I brutalized myself cleaning out the very small and numerous, and deeply dirty, grout lines and putting down white epoxy grout. That improved the look a lot. But it still never really looks clean. I am considering putting down a clear coat of that tough epoxy paint found on garage floors or cool art gallery floors. Basically, my idea is to give it some gloss and also to create a smooth (but with non-slip additive) surface on the theory that all the millions of little grout lines were just magnets for dirt particles; I imagined an easy to clean, glassy surface.

Rather than clear epoxy, the store recommended a gloss sealer & finish (the bottle mentions terra cotta, flagston, slate, and saltillo but not porcelain).

Since this is kind of a permanent decision (any of this stuff is hard to get off), I want to make sure I don't do something stupid. I'm inclined to the epoxy as my experience with the epoxy grout was that it is very durable and easy to clean.

So my question: Which approach would be best to create a gloss surface that is easy to clean and not so rough it attracts filth?


Thank you for your question Rich,

   Sorry I am a bit tardy with my response to you, work has been busy lately.

   I understand your dilemma having had to deal with the material you are now wrestling with. Typically the old school install of this mosaic material is a screed mud job that as you can see can stand the test of time even if the material on top has somewhat degraded over time. Porcelain is only exceeded by one material for limited porosity on its That being said anything less than the strongest coating is not going to have a chance of surviving long term. I would also be leaning to the epoxy coating even though there is a limited color pallet to choose from (color chips included). Preparation as you can totally understand (having scrubbed and labored over trying to restore the mosaic) is key so I would consider a mild acid wash (Sulfamic Crystals or Phosphoric Acid) and then neutralize with a Baking Soda rinse (twice)and let dry for 72+ hours before attempting the coat. A "sealer" (gloss or otherwise) will not be your friend as they tend to lift or peal when applied over a Porcelain material, with a sealer no porosity no bonding...follow me? Something else you may consider is perhaps installing a "tile over tile" application as this process also has possiblities in the design scheme of things. If you should consider that just come back and we can talk about that as needed. Ok Rich I hope this helps you with your project, feel free to return anytime...

Perry V.

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Perry Vellenga


Ceramic Tile/Marble. I can answer questions about floor preparation, tile selection, layout questions, performance of products, expectations of finish, compatabilities, questions about grout and epoxies, evaluating an installer, asking the right questions to check competence...more? 33 years this August 2012/ many years in commercial application from exterior finishes to Mall store fronts/ interior finishes like floor packages in stores inside Malls examples: The Limited, Lerner/NY, Lane Bryants, Bombay Co., Now involved in Residential new construction covering all types of interior finishes and designs.


I worked in an exclusive field of floorcovering called "Tenant Development" which is by invitational bid only, by way of a National bid list. These are large floor packages usually over 3500 sq. ft. of 18" x 18" Marble and Granite and many other types of Marble and sizes. They are specialty stores where the floor package can cost upwards of $50,000 for one store. I have also done "Structure" stores and J. Riggins stores, Lane Bryant,Express and Body Shop stores where wood flooring is used. Presently work for a National Flooring Company in the Residential new construction arena that covers most interior design elements..Granite Slab tops/wood flooring both job finished and prefinished ect..

My response's are published all across the Internet and picked up by multiple Interior Design sites and Industry related web sites where people have questions...

too many most of which don't count...

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