Microcement Over Tile: How to Prep the Surface

Going straight over existing tile is the thing microcement is best at. No demolition, no skip in the driveway, no disposal, and about 2 mm of added thickness instead of a new tile bed.

It is also where all the preparation lives. Get this part right and the tile underneath disappears for good. Get it wrong and the grout lines come back through the finish months later.

Check the tile is sound

Tap across the whole surface. Anything that sounds hollow is not bonded to what is under it, and it has to come out and be filled. A tile that is drummy today will move later, and microcement follows whatever moves beneath it.

Cracked tiles come out. Loose ones come out. Chips and the holes left by removals get filled flush.

Clean it properly

Tile in a bathroom or kitchen carries soap film, grease and cleaning residue, and primer will not grip through any of it. Degrease the whole surface and rinse it. Glazed tile that is very glossy benefits from a key — a light abrasion so the primer has something to hold.

Deal with the grout lines

This is the part people get wrong. Grout lines are not just cosmetic joints — they are where the surface moves. Deep or wide lines get filled so the surface starts flat.

Then the mesh. On any tile job you are on the Reinforced system: fiberglass mesh bedded into a structural build coat, spanning the joints so movement in the tile below cannot telegraph into your finish. This is not an upgrade you can skip on a tile job. It is the reason the job works.

The order of coats

Primer, to grip the tile. Two build coats with the mesh bedded into them. Two coats of microcement. Two coats of sealer. About 2 mm of finished thickness above the tile.

What it costs

Reinforced runs about $14 a square foot in materials for a typical room, doing the work yourself. A full bathroom — walls and floor, around 250 sq ft — comes to roughly $3,325 in product.

Compare that with the tile alternative honestly: tile itself is cheaper per square foot, but the tile job includes ripping out the old floor, disposing of it, repairing whatever is underneath, and paying a tiler. That is where the money actually goes.

Where it will not work

If the substrate moves, nothing you put on top of it will save you. A floor that flexes underfoot needs stiffening first. A wall with an active crack needs the cause fixed, not covered.

Microvella ships late 2026. Join the waitlist and we will email you the day it is ready to order.

Related: Microcement for tile and flooring installers · Doing it yourself · Shop the full system