How to apply microcement, start to finish

You apply microcement in layers. Primer first. Then either mesh and a build coat, or straight onto the microcement. Then two coats of sealer. Each coat cures in hours, not days.

The part nobody tells you is the arithmetic. A full Reinforced job is seven coats with two separate 12-hour cures buried in the middle of it. That makes it a realistic 2–3 day job, not a Saturday afternoon.

Here is the whole sequence, in order, with what happens after each coat.

Decide the system before you touch anything

The order of operations changes depending on what you are going over, so settle this first.

• Core is primer, microcement, sealer. It is for interior walls, bare concrete floors and indoor fireplaces.
• Reinforced adds mesh and a build coat between the primer and the microcement. You need it for anything wet, anything outdoors, and any floor that is not bare concrete — including straight over old tile.

If you are unsure which one your surface calls for, the systems page walks through it case by case. Get this wrong and you either overspend or you put a thin system over a substrate that moves. One of each product is $1,778 for Core and $2,676 for Reinforced, which works out around $8/sq ft and $14/sq ft — though small rooms cost much more per foot, because you cannot buy half a pail. There is more detail in our breakdown of microcement cost per square foot.

Step one: primer, and the sand you throw at it

Wipe the surface clean. It has to be dry and it has to be sound — primer bonds to what is there, it does not fix what is loose underneath.

Shake the pail well. Microvella Primer is single part and ready to use, so there is no mixing and nothing to measure. Roll one even coat. Keep it uniform. No puddles, no heavy spots where it pooled in a low corner.

Then, while it is still wet, broadcast kiln-dried sand over it. That sand is what gives the next coat something mechanical to grab. It is the step first-timers skip because it feels odd, and it is the step that decides whether the rest of the job holds.

Primer is one coat only, and it cures in 30 minutes to 4 hours before you move on. One pail covers 600–650 sq ft.

Step two: mesh and build coat, on Reinforced only

Skip this whole section if you are doing Core.

Sand the primer, then vacuum it clean. Lay the fiberglass mesh and fasten it with staples or a glue gun. Pull it tight. Every bit of slack and every wrinkle has to come out, because a wrinkle telegraphs straight through the finish and you will be looking at it for years. One roll covers 500 sq ft.

Build Coat is two parts. Measure Part A and Part B accurately and mix them fully — this is not a place to eyeball it. Trowel the build coat into the mesh, pulling tight as you go, and broadcast sand over it while it is wet, same as the primer.

Then a second coat. Coverage is 275 sq ft on the first coat and 310 sq ft on the second, which is your first hint that the first coat always eats more material than you expect. After the second coat, it cures for 12 hours. That is the first of the two long waits.

Step three: the microcement itself

Sand or grind the surface below, then vacuum clean. Whether you are coming off primer or off a cured build coat, the principle is the same: no dust, no ridges.

Stir the microcement, then add water a little at a time until it is workable. Trowel it on in a cloud — irregular strokes, not neat parallel passes — and keep a wet edge so you are never troweling into something that has started to set. Then work it with a float in figure-8 motions. That figure-8 is what gives you the movement in the finish rather than trowel tracks.

Two coats. Then 12 hours to cure. That is the second long wait.

Which microcement you use changes the look and the coverage:

Product	Character	Coverage (1st / 2nd coat)
Coarse	Large grain, natural stone look. Sand it heavily for smooth to the touch, or lightly to help with non-slip. Suits high-traffic walls, floors, bathrooms.	375 / 450 sq ft
Smooth	Fine finish, no visible grains. Plaster effect, several application styles. Suits walls, bathrooms, low-traffic floors.	600 / 725 sq ft

Worth knowing at this point: the microcement is waterproof in itself, before any sealer goes near it. That is a property of the material, not of the coating you put on top.

Step four: sealer, which is never optional

Light sand, vacuum, then wipe down with a microfiber cloth. The wipe matters — sanding dust left on the surface shows up as haze under the sealer.

Sealer is two parts as well. Measure Part A and Part B accurately. Roll it on and back-roll it, working evenly and avoiding heavy areas. Recoat once the first coat is dry. Two coats, every job, both systems.

The sealer is not what makes the surface waterproof. It protects the finish. But it goes on every single time, and treating it as an optional extra is the fastest way to ruin a job you just spent three days on. A pail covers 650 sq ft on the first coat and 750 on the second, and it cures in 2 hours after the second coat.

The whole order, and the real clock

Step	Coats	Cure before next step	Core	Reinforced
Primer	1	30 min – 4 hr	Yes	Yes
Mesh	—	—	No	Yes
Build Coat	2	12 hr after 2nd	No	Yes
Microcement	2	12 hr after 2nd	Yes	Yes
Sealer	2	2 hr after 2nd	Yes	Yes

Count the coats. Core is five. Reinforced is seven, and it contains two stacked 12-hour cures that you cannot compress, negotiate with or run a fan at. Add the troweling time on either side of them and you land on 2–3 days for a Reinforced job. Core has a single 12-hour cure, so it splits naturally across two days with the overnight doing the waiting for you.

Plan the room around that. You are not getting a bathroom back the same evening.

Where first-timers actually come unstuck

• Buying short. First coats always cover less than second coats — 275 versus 310 on the build coat, 375 versus 450 on Coarse. Run your numbers through the material calculator before you order, and remember you cannot buy half a pail.
• Skipping the sand broadcast. It is the mechanical bond. There is no substitute step later.
• Leaving slack in the mesh. Wrinkles do not trowel out. They show.
• Eyeballing Part A and Part B. Build coat and sealer are both two-part. Measure them.
• Sanding and not vacuuming. Every single stage says sand, then vacuum. The vacuum is half the instruction.
• Treating a cure time as a suggestion. Going back in at hour eight of a twelve-hour cure costs you the coat.

None of this needs a certification. Almost all microcement in the US is sold only to certified applicators — Microvella is not. Anyone can buy it, with no trade account and no proof you work in the trade. If you are new to the material entirely, start with what microcement is and come back here.

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