Substrate Preparation Materials
Primer Plus - primer
Which substrate preparation material to choose?
Primers and Strengthening
For improved system adhesion. Materials for equalising absorbency, strengthening surfaces and preparing substrates prior to microcement application.
Reinforcement Mesh
To reduce the risk of cracking. Suitable for floors, old tiling, board joints, problematic substrates and areas with higher movement risk.
Levelling and Equalising
For a stable system base. Helps prepare the substrate so that subsequent microcement layers properly bond to it.
Substrate Preparation Materials for Microcement
Substrate Preparation Materials are a crucial part of the microcement system. Microcement is a thin-layer material that reflects the condition of the substrate, so it is not enough to only address the final appearance of the coating. The substrate must be solid, cohesive, clean, dry and properly prepared.
In this category you will find products for strengthening, priming, reinforcing and equalising the substrate prior to applying microcement layers. Correct preparation greatly influences adhesion, durability, appearance and resistance of the finished surface.
Why is substrate preparation so important?
With microcement, most issues do not arise from the final coating itself, but from poorly prepared substrates. If the substrate is dusty, greasy, loose, damp, cracked or structurally unstable, these problems can eventually show through the finished surface.
Proper substrate preparation helps enhance layer adhesion, unify absorbency, minimise the risk of fine cracking and create a stable base for the entire microcement system.
When to use substrate preparation materials?
Before applying microcement on old tiling
Old tiles must be firmly fixed, not hollow, greasy or loose. Before microcement application, the surface must be degreased, roughened or treated with suitable primer to create a stable base layer.
Before applying on concrete, screed or plaster
Mineral substrates must be solid, dry, cured and dust-free. For absorbent surfaces, it is important to unify absorbency to prevent uneven drying and ensure proper bonding of microcement layers.
For floors and stairs
Floors and stairs are subject to greater stress than typical walls. Substrate preparation is therefore essential. Important aspects include stability, flatness, expansion joints, cracks, edges and potential reinforcement.
For plasterboard, construction boards and joints
With sheet materials, joints, transitions, corners and structural stability must be properly addressed. If the substrate moves or cracks at joints, the issue may pass through the final microcement layer.
Reinforcement Mesh under Microcement
Reinforcement Mesh helps reinforce the build-up and reduce the risk of fine cracks. We especially recommend it for floors, old tiles, board joints, larger areas, problematic substrates and locations prone to minor movement.
However, reinforcement mesh is not a miracle fix for a poor substrate. If the substrate is structurally unstable, damp, crumbly or has active cracks, these issues must be resolved before microcement application.
Priming and Equalising Absorbency
Primers help prepare the substrate for subsequent system layers. For absorbent substrates, they unify absorbency; for certain surfaces, they enhance adhesion; and on dusty substrates, they can aid in surface strengthening.
The correct primer depends on the specific substrate. Concrete, old tiling, plasterboard, plaster, anhydrite or existing coatings all require different preparation. Therefore, it is advisable to know the substrate type before selecting a primer.
What must the substrate for microcement meet?
The substrate must be solid, cohesive, dry, clean, degreased and free of loose particles. It must not crumble, peel, dust, or contain residues of adhesives, waxes, grease or non-cohesive paints.
For floors, flatness, expansion joints and any cracks must also be addressed. Microcement is a thin layer, so it cannot level out large unevenness or conceal structural substrate defects.
Common mistakes in substrate preparation
The biggest mistake is applying microcement directly on a poorly prepared surface. Typical problems include dust, grease, remnants of old coatings, hollow tiles, unresolved cracks, missing priming or covering active expansion joints.
Another common mistake is neglecting corners, junctions, edges, penetrations and board joints. These are the areas where substrate movement or inadequate preparation most often manifests later on.
Related categories and guides
Frequently Asked Questions about Microcement Substrate Preparation
Why is substrate preparation under microcement so important?
Microcement is a thin-layer system that reflects the substrate’s condition. If the substrate is poorly prepared, it can result in reduced adhesion, cracks, unevenness or shorter surface lifespan.
Is it necessary to use a primer under microcement?
In most cases, yes. Priming helps unify absorbency, strengthen the surface or improve adhesion of subsequent layers. The primer type depends on the specific substrate.
When to use reinforcement mesh under microcement?
We recommend reinforcement mesh mainly for floors, old tiles, board joints, larger areas and problematic substrates. It helps reinforce the build-up and reduce the risk of fine cracks.
Can microcement be applied on old tiles?
Yes, provided the tiles are firmly fixed, not hollow and the surface is properly prepared. The tiles must be degreased, roughened or treated with an appropriate primer and covered with a base layer to unify the substrate.
Does the substrate need to be perfectly flat?
The substrate does not need to be laboratory perfect, but it must be stable and sufficiently flat. Microcement is a thin layer, so large unevenness or poorly repaired details may show through the final surface.
Does microcement cover cracks in the substrate?
Not reliably. Active cracks and structural substrate movement must be resolved before application. Microcement is not a structural repair for cracking substrates.
What to do with expansion joints?
Active expansion joints must be respected or technically correctly resolved. Simply covering them with a continuous microcement layer may allow cracking to eventually show through the surface.
How do I know if the substrate is suitable for microcement?
The substrate must be solid, cohesive, dry, clean, degreased and free of active cracks. If unsure, it is advisable to send photos and a description of the substrate for assessment.
Not sure about substrate preparation?
Send us a photo of the substrate, the room type and intended microcement use. We will recommend suitable preparation, reinforcement, priming and subsequent system layers.
Advice on Substrate Preparation