Celluloseether für
Wasserfester MörtelHPMC and HEMC / MHEC Solutions for Water Retention, Workability, Anti-Sag Behavior, Consistency, and Application Stability in Cement-Based Waterproofing Mortar Systems.

HPMC (Hydroxypropyl Methyl Cellulose) and HEMC / MHEC (Hydroxyethyl Methyl Cellulose) are the most commonly used cellulose ethers in waterproof mortar. Both types improve water retention, workability, anti-sag behavior, mortar cohesion, and application consistency across different waterproofing system types and application conditions.

HPMC improves water retention, workability, mortar consistency, cohesion, and surface finishing behavior in waterproof mortar formulations. It helps mortar retain moisture during application and early curing, reduces troweling harshness, and supports more uniform layer formation across the waterproofed surface.

HEMC / MHEC improves water retention, anti-sag behavior, vertical application stability, open working time, and controlled finishing in waterproof mortar systems. It is particularly useful in basement waterproofing, wall waterproofing, and exterior façade waterproofing where anti-sag performance and extended open time are primary requirements.

Water retention prevents waterproof mortar from losing moisture too quickly to absorbent substrates. Adequate water retention supports cement hydration, crystalline growth (in crystalline systems), workable consistency during application, and more uniform barrier layer formation.

A common reference dosage range is 0.15%–0.50% by dry weight, depending on waterproofing system type, application area, target anti-sag performance, and viscosity grade. Vertical and exterior applications typically require higher dosage levels (0.20%–0.50%). Final dosage must be confirmed through laboratory testing and field evaluation.

Yes. Suitable HPMC and HEMC / MHEC grades improve wet mortar yield stress and internal structure, helping waterproof mortar stay in position after application on vertical walls, basement surfaces, and other non-horizontal areas.

Both are effective in waterproof mortar systems. HEMC / MHEC is often preferred for vertical applications, basement waterproofing, and exterior façade systems where anti-sag behavior and open time are the primary targets. HPMC provides versatile water retention, workability, and consistency support across flexible, rigid, and polymer-modified waterproofing systems.

Cellulose ether is used at low dosage levels in waterproof mortar and primarily affects fresh mortar properties — water retention, workability, anti-sag behavior, and consistency. It does not directly provide waterproofing function. Waterproofing performance is determined by the overall formulation design, including hydrophobic additives, crystalline agents, polymer powder, cement content, and application quality.

Start by identifying the waterproofing system type, primary application area, surface geometry, substrate absorption, target anti-sag performance, polymer system, and climate conditions. LANDERCOLL can help recommend suitable HPMC or HEMC / MHEC grades based on your specific formulation and waterproofing application requirements.

Yes. LANDERCOLL can arrange product samples of HPMC and HEMC / MHEC for waterproof mortar formulation testing and evaluation. Contact our team with your waterproofing system type, current formulation direction, application area, and performance requirements to receive a suitable sample recommendation.