BAUMIT MC55W Multi-Purpose Bonding Mortar
£23.74 (inc. VAT £28.49)
Natural-white, fibre-reinforced multi-purpose bonding mortar.
144 in stock (Available for Backorder)
Baumit MC55W is a natural-white, fibre-reinforced multi-purpose bonding mortar.
MC55W is suitable as a remediating plaster over existing stable, mineral and synthetic-resin-based plasters, renders and paintwork. Also suitable as a keying coat on concrete and insulating boards or as a finish render on concrete formwork and fair faced masonry.
• Multi-purpose contact mortar
• Fibre reinforced
• For all mineral substrates
Easy to use contact mortar with a range of uses
| Grain Size [mm] | Colour | Bag Size [kg] | Consumption [kg/sqm/mm] | Coverage/bag [sqm/6mm] | Bag per pallet |
|---|---|---|---|---|---|
| 0 – 1.2mm | buff/cream | 25 | 1.0 | 4.2 | 42 |
| Dimensions | 240 × 60 × 6 cm |
|---|---|
| PACKAGING | BAG, PALLET |
FAQs
Frequently Asked Questions (FAQs)
What is BAUMIT MC 55 W MultiContact Bonding Mortar?
BAUMIT MC 55 W MultiContact is a natural-white, fibre-reinforced multi-purpose bonding mortar used to prepare and strengthen mineral and other substrates prior to rendering or plastering. It combines good adhesion with breathable properties for interior and exterior use.
What are the primary uses of MC 55 W?
MC 55 W is suitable for:
• Preparing smooth masonry, concrete and existing render surfaces for further coats.
• Acting as a keying or bonding coat to help basecoat renders adhere.
• Providing a reinforcement layer with embedded mesh over mineral basecoats or selected render carrier boards.
• Serving as a thin topcoat over sound substrates where appropriate.
These uses make it versatile in many renovation and new build systems.
How do I mix and prepare MC 55 W?
To prepare the mortar:
1. Empty the dry powder into clean water in a clean container.
2. Mix using an electric hand mixer or render spray machine to a smooth, lump-free consistency.
3. Let the mix rest briefly (about 5 minutes), then remix before use.
Do not remix mortar that has begun to set.
What are the application thickness recommendations?
• As an adhesive for bonding insulation boards: 5 – 20 mm to ensure adequate contact with the substrate.
• As a basecoat reinforcement layer: 3 – 8 mm depending on board type, with reinforcing mesh embedded during application.
· For Woodfibre Insulation boards we recommend a basecoat of 6-8mm with an embedded Startex mesh in the top 3rd of the basecoat.
• On masonry substrates: a typical thickness of around 10 mm is recommended.
Follow the specified range to ensure proper adhesion and performance.
What technical properties does MC 55 W have?
Key performance values include:
• Reaction to fire: A2-s1-d0 (non-combustible).
• Compression strength: approximately 1.5 – 5 N/mm².
• Adhesive tensile strength: ≥ 0.08 N/mm².
• Water vapour resistance (μ-value): ≤ 25.
• Thermal conductivity: ≤ 0.890 W/mK.
These values reflect its robustness and suitability as a breathable bonding and basecoat mortar.
How much coverage will one bag of MC 55 W provide?
Approximate coverage per 25 kg bag is:
• 5 – 6.25 m² as an adhesive/bonding coat @ 4-5mm.
• 4.1 m² as a basecoat @ 6mm.
Actual coverage depends on substrate texture and application thickness.
Where can MC 55 W be used?
MC 55 W can be used in both external and internal areas on concrete, mixed masonry and lime or lime-cement renders. Substrates should be sound, clean, dry, frost-free, and free from dust or contaminants before application.
Can MC 55 W be used with insulation systems?
Yes. MC 55 W is often used as a bonding mortar in conjunction with insulation boards and can be reinforced with mesh to form a stable basecoat layer for further render applications.
How should MC 55 W be stored?
Store in dry conditions on pallets, well wrapped and protected from moisture. Under correct storage, the product life is typically up to 12 months.