Surface Preparation
Surface preparation is a critical preliminary phase in microcement installation, involving the evaluation and treatment of the substrate to ensure optimal adhesion and longevity of the coating. This process typically begins with assessing the substrate's condition, such as concrete, tiles, or plaster, to identify issues like cracks, unevenness, or instability that could compromise the thin microcement layer, which is generally no more than 3-4 mm thick.[42][43][44]
During assessment, professionals check for substrate stability by verifying flatness, with irregularities that could compromise adhesion requiring correction, and perform tensile strength tests, aiming for at least 1.5 N/mm² to confirm the base can support the microcement without future movement. Moisture levels are also evaluated using a moisture meter, ensuring humidity does not exceed 5% to prevent issues like delamination, particularly on porous surfaces like plaster or in damp areas. Cracks or loose elements, such as powdery mortars or unstable tiles, must be repaired or removed to achieve a solid foundation.[43][45]
Cleaning follows assessment to remove contaminants that could hinder adhesion, involving sweeping or vacuuming loose debris, using industrial cleaners to eliminate grease, dust, or stains, and ensuring the surface is completely dry. For tiled or non-porous substrates, joints are filled with base microcement products like Microbase to create a uniform plane, while protective measures such as masking tape or plastic sheeting are applied to adjacent areas. This step is essential for promoting a clean bonding surface.[42][43][46]
Priming is then applied as an adhesion promoter, with the choice depending on substrate porosity: non-porous surfaces like tiles receive products such as Primacem Plus along with fiberglass mesh for reinforcement, while porous ones like plaster use absorbent primers like Primacem Abs. The primer is typically rolled on, allowed to dry for 30 minutes to 24 hours, and may involve additional layers or silica sand for moisture-prone areas to enhance cohesion and prevent premature drying of the microcement. This treatment improves bonding and surface uniformity.[42][43]
Key tools and materials for surface preparation include grinders or roto-orbital sanders for leveling uneven areas, fillers like quick-setting mortars for crack repairs, industrial vacuum cleaners for dust removal, moisture meters for humidity testing, and rollers or brushes for primer application. Fiberglass mesh and specific primers tailored to the substrate complete the materials list, enabling precise preparation.[42][43][46]
The importance of thorough surface preparation lies in ensuring base stability to avert future cracking or failure, as microcement's thin application relies on a flawless substrate for durability and aesthetic results, aligning with established construction best practices that emphasize adhesion and load-bearing integrity.[42][43][44]
Application Techniques
The application of microcement involves a multi-layer process that requires precision to achieve a seamless and durable finish. Typically, the process begins with a base coat applied directly onto the prepared surface using a steel trowel to ensure even coverage and adhesion. This is followed by two to three body coats, each spread in thin layers of approximately 0.5-1 mm to build thickness and incorporate pigments for color, with each layer applied using spatulas or trowels for a smooth, continuous application. The final finish coat is then added, often with a textured or polished effect, followed by sealing layers to protect the surface and enhance its aesthetic qualities.[47]
Between each layer, curing is essential, allowing 4-24 hours of drying time between layers depending on the product and environmental conditions like humidity and temperature, to prevent cracking or unevenness, followed by mechanical sanding with appropriate grit sandpaper—coarse (40-80 grit) for base layers and finer (100-200 grit) for finishing layers—to polish the surface and promote interlayer bonding. This sanding step removes imperfections and ensures a flat profile before proceeding to the next coat, with full curing of the entire system taking 48-72 hours or more depending on environmental conditions like humidity and temperature. Polishing with finer abrasives in the final stages contributes to the material's signature smooth, matte appearance.[48][43][49]
Professional requirements are critical for successful microcement application, as the process demands skilled applicators trained in handling the material to avoid defects such as bubbles, cracks, or inconsistent thickness that could compromise the coating's integrity. Common tools include stainless steel trowels for precise spreading and mixing equipment to maintain the correct ratio of cement, resins, and additives during preparation. Due to the technical nature of the work, it is generally recommended that installations be performed by certified professionals rather than DIY enthusiasts to ensure compliance with industry standards and warranty validity.[41]
Techniques vary slightly for different surfaces to account for orientation and load-bearing factors. On horizontal floors, layers are applied in a consistent direction to facilitate even distribution and prevent sagging, with attention to thicker body coats for durability under foot traffic. For vertical walls, applicators use upward strokes with lighter pressure to counteract gravity, applying thinner layers and incorporating fiberglass mesh in the base coat for added reinforcement against potential delamination. These adjustments ensure uniform adhesion and aesthetic continuity across both surface types.[49]