Core Insulation

Wall build-up 3: Wood frame construction Exterior wall with 60 mm or 80 mm reed insulation as core insulation and exterior insulation

General requirements:
EnEV: U = 0.45 W/(m²K)
DIN 4108: R ≥ 1.20 (m²K)/W
+ (let) check wind and air tightness. Exterior insulation:
U-value: with a 6 cm external reed insulation panel: 0.33 W/(m²K).
With a 8 cm external reed insulation panel: 0.296 W/(m²K). Besondere Verarbeitungshinweise und Tipps für die Verwendung Schilfdämmstoff als Kern- bzw. Außendämmung bei Holzständerwerk: Bestand (Zimmerei): Holzständerwerk (z.B. 6 × 16 cm) sowie aussteifende Platte (z.B. 18 mm OSB) von Außen
  1. Cut the reed insulation layers to size for the core insulation and fit them between the timber beams and in front of the reinforcing panels.
  2. Attach 2 m x 5 m woven reed mats (Hiss Reet cloth) with horizontal stalks with the help of a staple gun to the timber studs.
  3. Filling in the hollow space with a light clay mixture.
  4. Plastering the fabric with clay rendering plaster. All over the clay a jute cloth has to be applied.
  5. Applying the final loam rendering.
  6. Fixing the exterior insulation to the wooden post-and-beam structure with appropriate wood screws and insulation discs.
  7. Lime rendering mortar can be applied directly to the reed insulation panels. The expert Gerhard Holzmann recommends the following plaster scheme consisting of four layers:
    a. Apply a layer of 8 -10 mm of levelling fibrated mineral rendering mortar (class P II (DIN 18550) or CS II (EN 998-1) directly to the reed insulation. Then, key the mortar.
    Corner beads should be implemented into the mortar layer.
    b. After app. 5 days (depending on the weather) apply a 10-15 mm layer of cement-lime machine-applied light plaster of the mortar class II (DIN 18550) or CS II (EN 998-1) with lightweight mineral aggregate. Again, key the surface after a 1 day drying time. This layer should leave a level surface.
    c. After about 12 hours (depending on the weather) apply a stopping coat of fibrated mineral rendering mortar (class P II (DIN 18550) or CS II (EN 998-1) with cloth insert (alkali resistant glass cloth, mesh width 6 x 6.5; tensile strength ≥ 2.8- 3.2 KN/ cm²) plaster joints and web reinforcement at wall apertures. The cloth should lie in the upper third of the stopping coat. Again, key this layer in preparation for the final rendering.
    d. Final rendering.
  8. Window reveals see wall build-up 1.

Disclaimer of Liability

The information given above is based on the calculations and information of HISS REET Schilfrohrhandel GmbH and the product specifications of the manufacturer. The content is only a selection of especially important information. The author reserves the right not to be responsible for the topicality, correctness, completeness or quality of the information provided. Liability claims regarding material or ideal damage caused by the use of any information provided, including any kind of information which is incomplete or incorrect, will therefore be rejected, unless there is evidence of intentional or gross negligence on part of the author. The information provided cannot substitute individual specialist advice by a planner. Authors: Dipl. Ing. Stefan Neumann
Dipl. Kfm. Philip Kullmann