What Can Microcement Go Over?

Microcement is about 2 mm of mineral coating. It follows what is underneath it, it does not correct it. So the two questions for any surface are the same every time: is it sound, and is it still.

Sound means bonded, clean and not failing. Still means it does not move or flex. Everything below is a variation on those two questions.

The quick version

Bare concrete slab — Core. The ideal substrate. Check it is clean, sound and has no curing compound left on it.

Drywall and plaster, dry interior — Core. Fill, sand and make it flat first. Every wave stays a wave.

Painted walls — Core, over sound paint that is well prepared. Loose, glossy or failing paint comes off first, exactly as it would before a repaint.

Existing tile — Reinforced. This is the one most people are here for. Every tile has to be bonded; anything drummy comes out and gets filled before you start. The mesh and build coat are what keep the old grout lines from telegraphing through. Full prep guide here.

Plywood and wood subfloors — Reinforced. Deal with deflection first, exactly as you would before tiling. A floor that flexes underfoot is not a candidate until it is stiffened.

MDF — Reinforced. Works, but respect the edges and keep it away from anything that will get it wet from behind.

Cement board — Reinforced. Fastening schedule and joints treated before anything goes over it.

Anything in a wet area — Reinforced, always, including the dry corner by the door. You do not want a system change running through a seamless floor.

Anything outdoors — Reinforced, without exception. A slab outside moves with temperature and ground conditions.

Which system you need

Core is primer, microcement, sealer. It covers interior walls, bare concrete floors and indoor fireplaces.

Reinforced adds fiberglass mesh bedded into a structural build coat. You need it for anything wet, anything outdoors, and any floor that is not bare concrete. The mesh is what stops movement underneath reaching your finish.

The things that disqualify a surface

Movement. A springy floor, a drummy tile, a substrate that is coming away. Fix it or remove it. Microcement will not hold a loose surface down.

Active moisture. A slab with water coming up through it is not ready for any coating.

Contamination. Grease, wax, polish, curing compound, silicone residue. Primer grips a clean surface, not a slippery one.

Structural joints. A movement joint carries through to the finish. You do not bridge one with a rigid coating and hope.

Where flatness matters more than you expect

This catches out good tile setters. Under tile you have a bed of thinset and a lippage allowance to absorb a high spot. Under microcement you have neither. A floor that would have been perfectly acceptable under tile can look visibly wrong under a seamless finish, because there are no joints to break up the eye.

Be stricter with flatness than you think you need to be. It is the single most common regret.

Not on this list?

Laminate, worktops, furniture pieces and odd substrates come up a lot, and the honest answer is that they depend on the specific piece — how it is built, how the edges are detailed, and whether it moves. Email us and describe it rather than working from a general rule.

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

Related: Microcement over tile: prep · For tile and flooring installers · Shop the full system