Can Mas Maya Coating Be Applied on Top of Microcement?

Mas Maya Coating can be applied over an existing microcement surface when the surface is properly prepared. The microcement must be flat, level, smooth, uniform, clean, dry, and stable before application. Because Mas Maya Coating is thin and expressive, any physical imperfections in the surface beneath will show through.

Mas Maya Coating is a natural, high-performance lime-based plaster composed primarily of limestone, white cement, and plant extracts. It provides a durable, breathable, water-resistant finish suitable for indoor and outdoor applications, including wet environments when the correct system is used. It is also free from VOCs.

Before You Start

Existing microcement should be inspected carefully before applying Mas Maya Coating. Do not apply over loose, crumbling, unstable, dusty, greasy, or contaminated surfaces.

Your surface must be:

Flat and level
Smooth and uniform
Clean, dry, and stable

What to do:

Remove old paint, loose tiles, flaking plaster, or any other loose or crumbling materials.
Remove all fittings such as sockets, switches, and light fixtures.
If there are any surface imperfections deeper than 3 mm, first level the surface using Mas Maya Prep.
Fill cracks and gaps with Mas Maya Prep as needed.
Clean the surface with a damp cloth or sponge.
In wet areas such as bathrooms, pools, exterior floors, or exterior walls, a waterproof membrane is required underneath the material. Confirm that this waterproof layer is intact before proceeding.

Important:

Mas Maya Coating is water-resistant, but it is not a substitute for waterproofing. In any wet zone, an intact waterproof membrane must be present beneath the surface before applying Primer and Coating.

Notes:

You can find detailed instructions on:

Tools You’ll Need

Steel trowels, flat and flexible
Toothed trowel, 5 mm
Plastic trowel for detailing or curved areas
Short-pile roller, 4 mm
Mixing paddle and bucket
Spray bottle
Mas Maya Foam Float
Protective gear: mask, gloves, goggles
Low-adhesive masking tape
Optional: moisture meter

Step 1: Protection and Edge Preparation

Use low-adhesive masking tape around floor edges, ceilings, corners, and frames.
Leave a 4 mm gap between the tape and the surface to allow the coating to settle cleanly into the edge without going over the tape.
Protect floors and surrounding surfaces with plastic sheeting.

Step 2: Apply Mas Maya Primer

Mas Maya Primer ensures strong adhesion between the surface and Mas Maya Coating.

Instructions:

Stir the Mas Maya Primer thoroughly before use.
Apply a thin, even layer with a short-pile roller, 4 mm, or brush.
Avoid puddles or heavy build-up.
For very absorbent surfaces, lightly mist with water first.
Wait at least 30 minutes, but no more than 24 hours, for the Primer to mostly dry while still tacky.

For pools and permanently wet areas, use Mas Maya Pool Primer instead of standard Primer.

Step 3: Mix Mas Maya Coating

Use the correct water mixing ratio for the application area:

Walls and ceilings: 330 ml water per 1 kg of powder
Floors: 400 ml water per 1 kg of powder

Instructions:

If using pigment, fully dissolve the pigment into the water as per the pigment instructions before mixing with Mas Maya Coating.
Add Mas Maya Coating to the water slowly, not the other way around.
Mix gently using a handheld plaster mixer. Avoid high-speed drills.
The mixture should have a smooth, creamy, yogurt-like texture.
Allow the mixture to rest for 15 minutes.
Mix once more before applying.
Use consistent batch sizes to ensure colour consistency across surfaces.

Step 4: Choose the Correct Application System

The correct system depends on the condition and location of the microcement surface.

For most installations, especially surfaces that may experience movement, moisture, or wear, use the 2 Layers with Mesh method.

Mesh is required when applying to:

Floors
Tiles
Wood
Pools
Surfaces with joints, cracks, texture, or movement

Mesh is also required in wet zones and is the standard method for long-term durability.

For standard smooth interior walls and ceilings in good condition, mesh may not be required. If the surface has joints, cracks, or is prone to movement, embed Mas Maya Mesh in the base layer.

Step 5: Base Layer with Mesh

This base layer provides structure and is used to embed the mesh.

Instructions:

Apply a 2 mm layer of Mas Maya Coating using the toothed side of a 5 mm toothed trowel.
Lay the Mas Maya Mesh on top of the material, leaving a 1 cm gap before any edges and overlapping mesh sheets by 10 cm. Once in place, press in the Mas Maya Mesh.
Begin at the top and press into the Mas Maya Coating using a flexible or steel trowel.
Using a flat-edged trowel, smoothen the Coating over the Mesh until it is barely visible.
Let dry until the surface is firm and no longer indents under light pressure. For example, you should not be able to alter the material by pressing in a finger. Alternatively, allow the material to dry completely before continuing with the Finishing Layer.

Step 6: Finishing Layer

This is the final visible layer of the surface.

Instructions:

Apply a 2 mm layer of fresh coating with a clean steel trowel.
Use smooth, overlapping strokes.
Keep the trowel edge clean to avoid drag.
Work wet-into-wet to avoid visible join lines. If an edge dries and work continues, a visible join line will show.
Plan ahead of time where you will stop working on a surface. Wherever possible, avoid stopping in the middle of surfaces, as this can cause lines in the material. Try to work to the edges of any surface.

Step 7: Smoothing and Polishing

To achieve the desired finish and close any open pores, smoothen the surface by reworking the remaining material with a light water mist using the Mas Maya Foam Float or a trowel.

Before starting this process, the material should be firm and can no longer be manipulated under light pressure. If using a moisture meter, the material should be between 15–20% moist.

Instructions:

Mist the part of the surface you are working on lightly with clean water.
Optional: Add a small amount of coconut soap to your water spray to help create more surface cream.
Use the Mas Maya Foam Float to glide over the surface in circular strokes until you have a creamy liquid on the surface. If the float sticks, mist more; it should glide smoothly.
Then use a flat-edged steel or plastic trowel to spread the surface cream while applying pressure to push down the material, fill in any small holes or inconsistencies, remove excess material, and flatten the finish.

The final surface should feel soft, polished, and even to the touch.

Step 8: Sealing

Mas Maya Sealer provides a matte, highly durable, waterproof finish suitable for high-traffic or moisture-prone areas.

Mas Maya Presealer must always be applied first — if Sealer is applied directly onto Mas Maya Coating, the colour will darken significantly and absorption will be uneven.

Sealing is required for floors, wet areas, and high-use zones. Seal only once the surface is fully dry.

For standard dry, low-contact interior walls and ceilings, sealing is usually not required unless the surface will be exposed to water, stains, or heavy use.

Sealing Step 1: Presealer

Apply a first thin, even layer of Mas Maya Presealer with a 4 mm short-pile roller.
Allow to dry, approximately 2 hours.
Apply a second thin layer with a 4 mm short-pile roller.
Allow to dry completely before applying Sealer.
Presealer locks in colour, closes any remaining pores, and prepares the surface for sealing.

Sealing Step 2: Sealer

Follow the Mas Maya Sealer instructions to mix together Part A and Part B sealer.
Stir slowly and let rest for 5 minutes.
Apply a thin, even coat with a short-pile roller.
Immediately follow with a dry roller to remove excess.
Apply two coats of Sealer.
Fully cured after 72 hours.

Sealing Step 3 (Optional): Heavy-Duty Sealer

Mas Maya Heavy-Duty Sealer is optional for high-traffic areas and recommended where maximum protection is needed.

Follow the Heavy-Duty Sealer instructions to mix together Part A and Part B Heavy-Duty Sealer.
Stir slowly and let rest for 5 minutes.
Apply a thin, even coat with a short-pile roller.
Immediately follow with a dry roller to remove excess.
Allow to fully dry and then apply a second thin coat, again using a dry roller to remove any excess.
Fully cured after 72 hours.

Special Notes for Wet Microcement Areas

If the existing microcement is in a bathroom, shower, wet room, pool, basin, exterior floor, or exterior wall, preparation must confirm that an intact waterproof membrane is present beneath the surface.

Mas Maya Coating is water-resistant, but it is not a substitute for waterproofing. If no membrane is present, one must be installed before applying Mas Maya Primer and Mas Maya Coating.

In wet zones, continue with the standard Mas Maya Coating system and always include Mas Maya Mesh for added reinforcement.

Final Result

When applied over a properly prepared microcement surface, Mas Maya Coating creates a natural, breathable, water-resistant, and durable finish. Correct surface preparation, the right water ratio, proper mesh use, careful smoothing, and the correct sealing system are essential for long-term performance.