The application method of gun-applied PU foam facilitates work and at the same time partly eliminates not only wet processes or technological breaks, but also the need of devices and working aids.

Basic application types

  • Gluing of thermal insulation boards
  • Gluing of brick blocks
  • Gluing of lining boards (e.g. based on wood or stone)
  • Gluing of inner as well as outer sills
  • Mechanical anchoring (ECORAW, SpiralAnksys system)

Gluing of ETICS thermal insulation boards

PU foam in the process of implementation of the external thermal insulation composite system (ETICS) is an alternative of cement binders used in the ETICS layered structure as the basic layer (adhesive). PU foam is suitable especially for gluing of boards based on foam plastic, e.g. polystyrene. In this case, an important parameter is mainly cohesion of the adhesive with the substrate and the adhesive with the thermal insulation boards.

Substrate preparation

  • Substrate without dust, efflorescence, blisters, active cracks, grease, high humidity
  • Substrate coherence at least 200 kPa
  • Levelness of (10 – 20) mm/m depending on the insulation type and type of connection to the substrate
  • Levelling of the substrate, sealing of inactive joints, restoration of expansion joints
  • Penetration (adhesive) / wetting (foam) of the substrate

Gluing of insulation boards

  • Installation of starting strips or laths
  • Applying foam on the boards along the perimeter + an irregular strip in the middle; coverage approx. 40% of the area
  • Gluing of the boards onto the surface from the bottom upwards with overlaps or tight joints
  • No joint between insulation boards may be formed in the place of a corner of the structural opening
  • Joints larger than 2 mm must be filled with the same insulation material (joints of EPS insulation up to 4 mm can be filled with foam)
  • The boards must not cover an expansion joint
  • Offcuts of boards are not used
  • Grinding of EPS after hardening of the adhesive mass

Further procedure according to the technological process of the ETICS manufacturer

Advantages compared to cement-based adhesives

  • suitable for all surface types and for larger uneven places
  • no penetration of the surface necessary, just wetting
  • no need to use more aids as a bucket, mixer, smoother, trowel, all you need is the application gun
  • elimination of the time necessary to stir up the cement mixture; PU foam in the can is ready for immediate use
  • polystyrene boards can be ground and mechanically anchored as early as after two hours from gluing unlike gluing with cement binders where this time period is 24 to 72 hours
  • saving of time and transport costs
  • PU foam is strong, elastic and at the same time thermally insulating
  • possibility to use even at temperatures around the freezing point

Related documents

  • ETAG 004 – External Thermal Insulation Composite Systems with rendering
  • Technical report 46 – Test methods for foam adhesive for External Thermal Insulation Composite Systems (ETICS)


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