Gypsum Plaster (Base Coat) – Interior Wall Base Plastering Material
Gypsum Plaster (Base Coat) by JOSME is an interior plastering product characterised by its coarse sand composition. It is composed of high-purity hemihydrate gypsum (Calcium Sulphate Hemihydrate), purified sand, lightweight aggregates, cellulose ethers, and specialised retarders. Appropriate for trowel application on concrete, aerated concrete, and brick-concrete wall and ceiling surfaces, this base coat provides a compressive strength of at least 2.5 MPa and a flexural strength of no less than 1.0 MPa. Featuring a very low VOC concentration, it complies with daily interior building safety regulations for both residential and commercial endeavours.
What Is This Product?
Conventional cement-sand mortar commonly encounters widespread construction issues such as drying shrinkage cracks, poor adhesion on either smooth or porous surfaces, and longer curing durations, all of which limit overall project development.
Gypsum Plaster (Base Coat) acts as a first levelling layer for AAC (Autoclaved Aerated Concrete) walls, concrete blocks, and masonry walls. It creates dimensionally solid foundational layers to underpin later finishing coatings and ornamental applications. Unlike traditional cement mortar, this gypsum base coat exhibits no shrinkage throughout the curing process and maintains consistent moisture regulation, making it suitable for prolonged interior wall applications.
Technical Parameters
| Parameter |
Value |
| Main Components |
Hemihydrate gypsum, washed sand, cellulose ethers, retarders |
| Application Method |
Trowel application |
| Setting Time |
60–120 minutes |
| Compressive Strength |
≥2.5 MPa |
| Flexural Strength |
≥1.0 MPa |
| Bond/Pull-Off Strength |
>0.4 MPa |
| Water Retention Rate |
>90% |
| Thermal Conductivity |
0.15–0.25 W/m·K |
| Fire Resistance Grade |
A-grade |
| VOC Content |
Ultra-low |
| Packing Specification |
20 kg per bag |
| Storage Temperature |
5°C to 35°C |
| Storage Conditions |
Cool and dry place |
Principal Gypsum Plaster (Base Coat) Benefits
Strong Adhesion: Good bonding to AAC blocks with concrete, eliminating voids in walls; adhesive strength more than 0.4 MPa.
Zero shrinking: This prevents shrinking and lessens the likelihood of fractures in large walls.90% water retention allows mortar on extremely absorbent surfaces to retain moisture.
Fire Resistance: Natural gypsum is naturally resistant to fire.
Extremely low volatile organic compounds. Suitable for ceilings, living rooms, and bedrooms.
0.15–0.25 W/m is the thermal conductivity.K: Meets the standards for sustainable construction and insulation.
Utilisations
Comprehensive Commercial: 60–120 minutes of preparation; ideal for big residential buildings and high-rise office complexes.
Luxury Home Remodelling: One-pass thick layer plastering for uneven walls saves time.
Concerns about hollow walls on permeable bases are resolved by AAC Block Walls' 90%+ water retention.
Interior ceilings should have minimal volatile organic compounds (VOCs) and a bond strength more than 0.4 MPa to avoid sagging.
Quality Control Process
JOSME tests each production run with five defined testing processes to guarantee consistent product performance:
Setting time (Vicat), bond strength (pull-off ≥ 0.4 MPa), fineness / sieve analysis, water retention rate and shrinkage / crack resistance are tested to verify that the grout complies
Packaging & Delivery
Each product bag is 20kg, adopting export-grade reinforced packaging to prevent leakage and structural damage during ocean transportation.
Lead Time: Standard Gypsum Plaster (Base Coat): 2–3 working days Custom formula and private label orders: 7–15 working days
We support sea, air and land transportation solutions according to order quantity and destination requirements.
FAQ
Q: Is this gypsum base coat appropriate for porous aerated concrete surfaces?
A1: Affirmative. The material has a binding strength of 0.4 MPa+ and maintains a water retention rate of 90%, ensuring consistent hydration and adhesion on AAC block surfaces, so efficiently averting hollow wall imperfections.
Q: What distinguishes gypsum base plaster from finishing putty?
A2: Gypsum base coat serves to achieve substantial levelling by rectifying significant flatness discrepancies. Finishing putty is used for meticulous surface refinement. The two substances fulfilll distinct building functions and are not interchangeable.
Q: Is this product suitable for use on indoor ceilings?
A3: Affirmative. It is suitable for ceiling plastering on clean and solid surfaces. Consistent bonding efficacy mitigates sagging problems, and the ultra-low VOC composition is appropriate for confined ceiling spaces.
Q: What are the reasons for wall fissures after plaster application?
A4: The primary cause of cracking is often unstable substrates or fast surface desiccation due to air movement. Securing windows during the preliminary setup and verifying substrate stability prior to construction helps reduce the likelihood of cracking.
Contact Us
If you have project quotation, sample testing and bulk order demands for Gypsum Plaster (Base Coat), please send your detailed requirements to our team via [email protected].
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