Thermal insulation THERMOWALL GF MAX

wood fiberrigid panelfor flooring

Brief description
Gutex Thermowall GF Max is a robust wood fibre insulation board with rounded profile for versatile use (roof, façade, interior fittings, floor). Designed for heavily loaded applications, it enables economical logistics through universal applicability.

Main benefits

• Very robust — higher raw density with increased compressive and tensile strength
• Flat and precise — ideal substrate for subsequent trades and renders
• Safe to install and easy to work with — clean joints and high dimensional accuracy
• Efficient — one product for multiple applications reduces stock variety

Applications

• Weatherproof temporary roof (UDP‑A) from 40 mm thickness
• External boarding directly on timber stud constructions and mass timber elements (behind cladding in ventilated façades)
• Renderable insulation board for Thermowall ETICS on timber studs and mass timber elements without ventilation (from 40 mm)
• Full-area insulation layer for service/installation level
• Internal insulation of external walls for direct rendering
• Load-bearing floor build-ups
• Full-area insulation under rafters
• Insulation of flat roof constructions on timber, concrete and metal structures

Product format / variants

• Format (nominal): 1900 x 600 mm
• Available board thicknesses: 40 mm, 60 mm, 80 mm

Installation instructions – General

• Lay boards with the marked side facing outwards
• Install boards lying flat, accurately and with tight joints
• Always back up butt joints; staggered joints at element seams permitted if a force- and form-fitting connection of wall elements exists (tension-, compression- and shear-resistant) or for roof elements immediately fixed with counter battens
• Place fixings sufficiently close to the board edge
• Do not install damaged boards
• Gutex Thermowall GF Max is not a load-bearing component (e.g. for snow loads)
• Avoid elevated moisture loads on the room side
• Runoff rainwater during the construction phase can soil adjacent components; ensure appropriate drainage
• Temperature resistance: up to approx. 110 °C (additional measures required at higher temperatures)
• Observe dust extraction and occupational safety

Installation instructions – Roof

• Maximum rafter spacing per board thickness: 40 mm → 90 cm; 60 mm → 110 cm; 80 mm → 125 cm
• Offset joints from row to row at least one rafter spacing
• Rafter spaces are not walkable
• No nail-sealing tapes/gaskets required for penetrations through the wood fibre board
• Execute connections and penetrations weatherproof with suitable adhesive/sealing systems
• At butt joints, penetrations or verge edges, seal profiles laterally
• Temporary roof (UDP‑A) weather-resistant for up to 4 weeks
• All joints > 0.5 mm must be reinforced immediately after installation

Installation instructions – ETICS

• Usable as a renderable insulation board in the Thermowall ETICS; follow system's render and mounting instructions

Installation instructions – Service layer / interior boarding

• Recommendation for interior boarding: single layer fermacell GF 12.5 mm full-area and free of cavities (horizontal mounting)
• Fixing recommendation (example for Thermowall GF Max 60 mm): on wood-based panel d ≥ 15 mm + Thermowall + fermacell GF d = 12.5 mm use special staples/nails as per manufacturers' recommendations
• Staple spacing: vertical ≤ 150 mm; horizontal ≤ 400 mm (at board edge ≤ 200 mm)
• Staple edge distance from board edge ≥ 25 mm; staples flush or max. 1 mm countersunk

Installation instructions – Ventilated rainscreen façade

• Maximum batten spacing 83.3 cm
• Execute connections and penetrations permanently wind- and driving rain-tight
• Fix boards immediately with ventilation battens; freely weatherable up to 4 months
• Stagger joints at least 30 cm

Fixing information

• Fixing with staples or nails possible up to 60 mm thickness; screws permissible—use approved fasteners and corrosion protection (e.g. galvanized)

Technical characteristics / specifications

• Raw density ρ: 185 kg/m³
• Vapour diffusion factor (μ): 3
• Declared thermal conductivity λD: 0.043 W/mK
• Design thermal conductivity λB: 0.045 W/mK
• Compressive stress / compressive strength: ≥ 150 kPa
• Short-term water absorption: ≤ 1 kg/m²
• Flow resistance: ≥ 100 kPa·s/m²
• Specific heat capacity: 2,100 J/kg·K
• Reaction to fire (EN 13501‑1): Euroclass E
• Product standard: EN 13171:2012+A1:2015
• Tensile strength perpendicular to board plane: 20 kPa
• Application according to regulations: UDP‑A (weatherproof temporary roof)