Sealing Slate

The before and after photographs below show the results of a recent shower tile renovation project we carried out at a property in Windsor. The shower cubicle was tiled with small square Slate Mosaic tiles which, over time, had suffered from heavy staining. The grout had become discoloured with built-up soap residue, body oils, and mildew growth, and in places this contamination had spread onto the surface of the tiles themselves, leaving the shower looking tired and unhygienic.

Cleaning a Mosaic Slate Tiled Shower room

To tackle the problem a strong dilution of Tile Doctor Pro-Clean was applied which is a professional-grade alkaline cleaner designed for dealing with heavy soiling. The solution was applied to the verticals using a paint roller and then left to soak in for five to ten minutes before being scrubbed into both the tile and grout. Applying it this way ensures better contact with the surface enabling it to stick to verticals better.

Maximalising dwell time is important as it helps the solution penetrate deep into the tile and grout line where it can get a head start breaking down the soiling. The tiles were then agitated using a silicone brush attached to a handheld rotary machine, which helped to release ingrained dirt and organic growth without damaging the slate surface.

During the cleaning process it became clear that the existing silicone sealant was failing, heavily stained and beyond cleaning. The only way to deal with this is to replace it and so it was removed entirely once the cleaning stage was complete. Removing old silicone ensures a cleaner finish and allows new sealant to bond properly later.

The shower was then left to dry overnight, which is an essential step before sealing natural stone.

Sealing a Mosaic Slate Tiled Shower room

The following day I returned to complete the renovation starting with checking the shower dry and ready for sealing. I confirmed this with a damp meter and then started applying the first of what would be two coats of Tile Doctor Colour Grow. This is an impregnating sealer that penetrates deep into the pores of the slate, enhancing the natural colours in the stone and providing long-lasting protection. This will ensure that moisture, soap residue, and other contaminants run straight off the tile and grout into the drain.

The final step was to apply fresh silicone sealant to all joints, completing the restoration.

As you can see from the photographs, the Slate Mosaic tiles responded extremely well to the cleaning and sealing process. The shower now looks significantly fresher, cleaner, and more vibrant very much like a new installation rather than a well-used one.

For aftercare cleaning I recommended the use of Tile Doctor Aqua-Pro which is a mild yet effective pH neutral tile and grout cleaner designed for everyday use in bathrooms.  It’s important to avoid using a strong product for cleaning sealed surfaces as this will breakdown the sealer with use.

Professional Renovation of a Slate Mosaic Tiled Shower in Berkshire