Etere di cellulosa per
Malta di RiparazioneHPMC and HEMC / MHEC Solutions for Anti-Sag Behavior, Water Retention, Workability, Shape Retention, and Vertical Repair Stability in Concrete Repair Systems.

HPMC and HEMC / MHEC are the most commonly used cellulose ethers in repair mortar. HPMC provides water retention, workability, cohesion, and consistency across a broad range of repair systems. HEMC / MHEC is particularly valued for stronger anti-sag behavior, vertical repair stability, and extended open working time.

HPMC improves water retention, workability, mortar consistency, cohesion, and finishing behavior. It helps repair mortar retain moisture after mixing, remain workable during shaping and finishing, and maintain stable consistency throughout the application process.

HEMC / MHEC improves water retention, anti-sag behavior, vertical repair stability, open working time, and controlled finishing. It provides stronger structural body than standard HPMC grades, making it particularly suitable for vertical, overhead, and thick-layer repair applications.

Repair mortar is frequently applied on vertical walls, columns, beam soffits, and irregular surfaces where gravity acts against the freshly placed material. Without sufficient anti-sag behavior, the mortar slides or sags immediately after application — wasting material, requiring rework, and making controlled finishing impossible.

A common reference dosage range is 0.15%–0.50% by weight of dry mortar, depending on repair type, application thickness, target anti-sag performance, and viscosity grade. Vertical repair and thick-layer systems typically use higher dosages of 0.20%–0.50%. Final dosage must be confirmed through formulation testing.

Yes. Suitable HPMC or HEMC / MHEC grades improve wet mortar internal structure and cohesion, helping repair mortar hold the shape given by the applicator around edges, holes, corners, and irregular repair geometries until the material begins to set.

Cellulose ether can help reduce cracking related to rapid drying by improving water retention and supporting more stable early-stage cement hydration. However, final cracking performance also depends on shrinkage control additives, fiber reinforcement, curing conditions, application thickness, and overall formulation design.

Stickiness is typically caused by excessive cellulose ether dosage, an unsuitable high-viscosity grade, high redispersible polymer powder content, excessive water addition, or an unbalanced filler and sand system. Reducing the cellulose ether dosage or switching to a lower-viscosity grade usually helps resolve this issue.

For vertical repair mortar, prioritize anti-sag performance, structural body, and water retention. HEMC / MHEC at medium to high viscosity grades is typically the preferred choice. Share your application thickness, substrate condition, working time requirement, and surface finish target with LANDERCOLL for a specific grade recommendation.