Description
Product:
Factory prepared dry powder, natural white, mineral-based, fibre-reinforced, multi-purpose bonding mortar according to EN 998-1. Suitable as a remediating plaster. Also suitable as a keying coat on concrete and insulation boards or as a finish render. For manual and machine application.
Use:
Multi-purpose contact mortar: As a keying coat to prepare smooth concrete substrates to receive standard basecoat and topcoat renders (CS I and CS II). As a thin to medium reinforcement layer (with reinforcing mesh) over mineral basecoat renders, synthetic renders, thermal renders and selected render carrier boards. Suitable as a topcoat layer over sound mineral substrates (CS II and CS III), concrete, synthetic renders, and stable painted surfaces.
Properties:
Mineral, modified and easy to use contact mortar with a range of uses.
Once cured, the product has good bonding strength, is water vapour permeable and resistant to weathering, water ingress and frost penetration.
For use in external and internal areas.
Composition:
White cement, white lime, lightweight additives and additives to improve workability, adhesion and strength (fibres).
Yield:
ca. 8m2 / bag (nominal 3 mm thick)
Consumption:
1.0 kg/m2 / mm
Substrate:
Suitable substrates include concrete, mixed masonry and lime/lime-cement render. Substrates must be sound, clean, dry, free from frost, dust and efflorescence.
Basecoat renders should be fully cured. Existing mineral and organic based coatings and paints must be sound and well bonded to the substrate (pull off test and/or cross cut test).
Peeling paint, lime wash, grease stains (from shuttering), other contaminants and film forming layers must be removed. Any cracks are to be scraped open with a pointed tool to form a V groove. High suction substrates and gypsum substrates must be pretreated with Baumit Hydrosol.
Friable basecoats are to be pretreated with a stabiliser such as Baumit ReMineral/PutzFestiger. Algae and mould growth must be removed with a fungicidal wash such as Baumit FungoStop.
Application:
Mixing: Baumit MultiContact MC 55 W can be mixed with clean water in a tub to a lump free, creamy consistency with an electric hand mixer. Material which has started setting must not be remixed with water. Mixing with other products (e.g. anti-freeze agents or accelerating agents) is not permitted.
Automated continuous horizontal mixers may also be used. For small areas the contact mortar can be manually applied. For larger areas the freshly mixed mortar can be fed into a mortar pump for spray application. Alternatively, a mortar mixing pump will provide an all-in-one mixing and spraying solution.
Preparation of concrete, render and plaster substrates and remediation: Baumit MultiContact MC 55 W is applied to a thickness of 3 5 mm (with embedded Baumit StarTex reinforcing mesh where necessary) and the surface keyed with a brush or plasterer comb. Gypsum substrates must be pretreated with Baumit Hydrosol before applying a max. 2-3 mm thick layer of the contact mortar.
Reinforcement layer over render coatings and selected render carrier boards: Baumit MultiContact MC 55 W is applied with a stainless steel notched trowel (10 mm notches). Continuous sheets of Baumit StarTex reinforcing mesh are placed onto the contact mortar, free of creases and with 100 mm overlapping edges. A further 1-2mm of contact mortar is applied wet on wet over the embedded reinforcing mesh. Excessive trowelling is to be avoided. Trowel lines are to be removed after hardening. The overall thickness of the reinforcement layer thickness must be from 6 8 mm.