Web Menu

Product Search

Language

Share

Exterior Insulation Finishing System Additives

-- Steady & Reliable Manufacturer --

Introduction

Exterior insulation finishing system (EIFS) and external thermal insulation composite system (ETICS) additives are the chemical performance components that make modern facade insulation systems durable, weatherproof, and crack resistant. An ETICS facade consists of an insulation board (EPS or mineral wool) adhered to the wall structure, a base coat reinforced with fiberglass mesh, and a decorative finish coat — and every layer relies on precisely formulated cellulose ether and polymer additive systems.

The adhesive mortar bonding the insulation board and the base coat reinforcing layer are the two most additive-critical components. HPMC provides water retention, workability, and open time; RDP delivers the flexibility and crack bridging that allows the system to survive decades of thermal cycling, wind loading, and rain exposure without delamination or cracking.

Specification

Parameter HPMC (ETICS Adhesive Grade) HPMC (ETICS Base Coat Grade) RDP (ETICS Grade)
Viscosity (2%, 20°C) 80,000–150,000 mPa·s 40,000–100,000 mPa·s N/A
Dosage in adhesive (%) 0.3–0.45 — —
Dosage in base coat (%) — 0.25–0.40 2.0–5.0
Water retention (%) ≥97 ≥96 —
Gel temperature (°C) 65–80 60–75 —
MFT (RDP) — — ≤5°C
Tg (RDP) — — -10 to +5°C
Moisture content (%) ≤5 ≤5 ≤2
Ash content (%) ≤5 ≤5 ≤10
Particle size 80–100 mesh 80–100 mesh 400–600 μm

ETICS system additives are available in certified grades with EN 13499 / EN 13500 test documentation support.

Application

  • EPS board adhesive mortar: HPMC at 0.35–0.45% provides 30+ minute open time — essential for aligning large insulation boards on tall facade sections. RDP at 1.5–3.0% improves peel adhesion to EPS.
  • Mineral wool board adhesive: Higher-viscosity HPMC (120,000–150,000 mPa·s) manages the higher water absorption of mineral wool substrates without premature dehydration.
  • Base coat (reinforcing layer): HPMC at 0.25–0.40% + RDP at 3–5% delivers the combination of workability and crack-bridging flexibility required by EN 13499 (EPS systems) and EN 13500 (mineral wool systems).
  • Finish coat (top render): Medium-viscosity HPMC at 0.2–0.35% in silicone-modified or acrylic finish coats controls application consistency and prevents rapid drying on sun-exposed facades.
  • Insulation board bedding on existing facades: HPMC + RDP base coat is used as the leveling and bonding layer when retrofitting ETICS insulation over existing rendered or painted facades.
  • Tropical and coastal climate ETICS: UV-stable, high-Tg RDP grades combined with high-viscosity HPMC deliver enhanced weathering resistance in high-humidity, high-UV, and salt-air environments.

Advantage

  • Long open time for large-board installation: HPMC at 0.40–0.45% delivers ≥30 minute open time, enabling single-operator alignment of 1200×600 mm EPS boards without rush-induced errors.
  • Freeze-thaw cycle resistance: RDP-modified base coats maintain ≥1.0 N/mm² tensile adhesion after 25 freeze-thaw cycles per ETAG 004 testing — critical for northern European and high-altitude applications.
  • Crack-bridging at base coat level: Base coats with RDP at 4–5% achieve crack-bridging capability of ≥0.3 mm per EN 1015-19, protecting the fiberglass mesh reinforcement from moisture penetration.
  • System-level compatibility: Supplying HPMC and RDP from the same source eliminates inter-product incompatibility — a common cause of adhesion failure in ETICS systems where additives from different manufacturers interact unpredictably.
  • Regulatory documentation support: We provide Declaration of Performance (DoP) supporting data and EN 13499/13500 formulation reference data to assist customers in system-level CE marking processes.
  • Climate-adapted grade range: We offer HPMC grades with gel temperatures from 58°C to 90°C and RDP grades from standard to high-Tg variants, enabling formulation optimization for hot-arid, temperate, and cold-climate deployment.
  • Q: What HPMC viscosity is recommended for EPS board adhesive mortar in an ETICS system?
  • A: For EPS board adhesive mortar, HPMC viscosity in the range of 100,000–150,000 mPa·s (2% solution, 20°C) is most commonly specified. This viscosity range delivers ≥30 minute open time and sufficient sag resistance to hold large EPS boards in position on vertical walls after placement. For mechanically applied adhesive, a slightly lower viscosity (80,000–100,000 mPa·s) is preferred to maintain pump throughput.
  • Q: How much RDP is needed in the ETICS base coat to pass EN 13499 tensile adhesion after aging?
  • A: To meet EN 13499 tensile adhesion requirements after heat aging (70°C, 7 days) and freeze-thaw cycling (25 cycles), RDP dosage in the base coat typically needs to reach 3.5–5.0% by dry weight. Formulations with RDP below 2.5% often fail the tensile adhesion after freeze-thaw aging test, especially on EPS substrates where the failure mode shifts to cohesive failure within the base coat layer.
  • Q: Can the same HPMC grade be used in both the adhesive and base coat layers of an ETICS system?
  • A: A single HPMC grade can be used across both layers if it falls in the 80,000–120,000 mPa·s range — this provides adequate open time for the adhesive layer and suitable water retention for the base coat. However, optimal system performance typically uses a higher-viscosity grade (120,000–150,000 mPa·s) in the adhesive and a medium-viscosity grade (60,000–100,000 mPa·s) in the base coat, where faster surface drying and less tack are desirable.
  • Q: Do your ETICS additives support CE marking documentation for facade systems?
  • A: Yes. We can provide product-level technical documentation including TDS, SDS, Declaration of Performance (DoP) supporting data, and EN 13499/13500 reference formulation data to assist system manufacturers in their ETICS CE marking process. We also support customers with third-party test planning and can recommend accredited testing laboratories in Europe and China for system-level qualification testing.
  • Q: What is the difference between EIFS and ETICS, and do the additive requirements differ?
  • A: EIFS (North American standard) and ETICS (European standard, EN 13499/13500) refer to the same class of exterior insulation composite facade systems. The additive chemistry requirements are largely identical — both require high-performance HPMC for water retention and open time, and flexible RDP for crack resistance and adhesion. The key difference is in the test standards: EIFS qualification follows ASTM/ANSI standards while ETICS follows EN standards. We supply grades referenced against both standard families and can provide appropriate documentation for either market.
About Us
Zhejiang Yisheng New Material Co., Ltd.
Zhejiang Yisheng New Material Co., Ltd. is a professional enterprise engaged in the design, development, manufacturing, application, and sales of cellulose ether, located in the Shangyu Economic and Technological Development Zone, part of the Hangzhou Bay National Industrial Park. With a core concept of safety, environmental protection, and sustainable development, the company boasts an annual production capacity of 15,000 tons of cellulose ether, offering a complete range of products including HEC (hydroxyethylcellulose), HEMC (hydroxyethyl methylcellulose), and HPMC (hydroxypropyl methylcellulose). Our products serve various sectors such as oil fields, coatings, dry powder mortar, cosmetics, personal care products, medicine, and many others. Yisheng has a global presence, providing stable cellulose ethers and services to customers worldwide.
As a professional China Exterior Insulation Finishing System Additives Supplier and Exterior Insulation Finishing System Additives Company, The company adheres to the principles of safety and environmental protection as the foundation of its development. It implements and further consolidates safety and environmental protection measures, striving to create green and environmentally friendly production processes, safe and effective control systems, and orderly production management. This approach lays a solid foundation for the company's sustainable development. Yisheng boasts a scientific management mechanism, a comprehensive quality management system, stringent product testing methods, advanced technology, state-of-the-art equipment, and high-quality after-sales service.
Zhejiang Yisheng New Material Co., Ltd.

+86-18067879812
Zhejiang Yisheng New Material Co., Ltd.

sarah@ys-cellulose.com
Zhejiang Yisheng New Material Co., Ltd.