Mapei Mapetherm AR1 GG is a one component cementitious mortar for bonding, levelling and reinforcing thermal-insulating panels and thermal insulation systems.

Recommended Use 

• Bonding all types of thermal-insulating panels (foam/extruded polystyrene, expanded polystyrene, mineral fibres, cork, etc.) directly on render, masonry and concrete on walls and ceilings.
• A reinforcing coat for thermal-insulating panels with embedded fibreglass reinforcing mesh on internal and external walls (thermal insulation system).

Application Examples

Bonding and smoothing internal and external insulating panels and thermal insulation systems on:

• cementitious render or lime-mortar render;
• concrete;
• concrete blocks;
• approved render boards;
• brickwork. Also suitable for bonding insulation panels and reinforcing coat systems for:
• insulating inside faces of walls in rooms above ground;
• insulating inside faces of retaining walls in basements;
• insulating inside faces of loft ceilings;
• insulating external faces of ventilated façades;
• for use as a dash receiver and brick slip adhesive, plus synthetic brick slip or tile adhesive;
• for use with MAPEI approved backing boards as a render only system on to steel and timber framed buildings.

Characteristics 

Mapetherm AR1 GG is a grey or white powder made from cement, selected sand, synthetic resin and special additives with a fine grain size of up to 0.6 mm, developed according to a formula developed in MAPEI’s own research laboratories. When mixed with water, it forms a mortar with the following characteristics:

• low viscosity and, therefore, good workability;
• high thixotropic consistency: Mapetherm AR1 GG may be applied on vertical surfaces without running and without the risk of insulating panels slipping, including large sized panels;
• bonds perfectly to all materials normally used in the building industry;
• hardens without shrinking.

Recommendations 

• Do not use Mapetherm AR1 GG to bond insulating panels on metallic surfaces or substrates subject to large movements.
• Do not use if the panels have a smooth surface, good bonding may be impeded: polyurethane or mineral fibres with a surface coating of kraft paper, extruded polystyrene with a surface skin, etc.
• Do not bond the insulating panels on deteriorated substrates or crumbling render.

Application

Preparation of the substrate

The substrate must be sound, strong and free of dust, loose parts, grease, oil, adhesive etc. It is recommended to use Nivoplan or Mapewall GPR to even out variations in masonry or cementitious substrates. Gypsum substrates must be perfectly dry, free of dust and treated with Primer G before bonding insulation panels.

Preparation of the mix

Pour the Mapetherm AR1 GG while mixing in a container with 20-24% by weight of clean water (approx. 5.0-6.0 litres of water per 25 kg of powder). Stir the mix, preferably with a lowspeed mixer to avoid drawing in air, until a smooth, creamy, lump-free paste is obtained. Let the mix stand for 5 minutes, and stir again briefly before use. The mix obtained remains workable for approximately 3 hours.

Spreading the mix

Used as adhesive;

Spread Mapetherm AR1 GG directly on to the back of the panels, in an even layer, using a 10 mm notched trowel when the substrate is flat, or with a minimum coverage of at least 40% using a perimeter band, with additional central dabs, if the substrate is uneven. After applying, press the panels down well to guarantee a secure bond to the substrate and check the flatness with a straightedge.

Used as smoothing and levelling compound;

Once the adhesive is completely dry, at least 24 hrs after fitting the panels, install specified Mapetherm fixings, before spreading an even layer of Mapetherm AR1 GG on the surface and then embed Mapetherm Net alkali-resistant glass fibre mesh in the mortar. The Mapetherm Net must be pressed down with a smooth trowel on the fresh layer of mortar, and must overlap by at least 10 cm along the joints. After 12-24 hours, apply a second layer of Mapetherm AR1 GG smoothing and levelling compound to form a compact, even surface suitable for the final coating which must only be applied once the smoothing layer is hardened and cured.