Rainproof underlay panel for roofs and walls
Gutex Ultratherm is a durable roof underlay panel with a patented tongue-and-groove profile that combines maximum weather protection with excellent insulation performance. It is rain- and hail-resistant, and provides effective protection against cold and heat thanks to its high heat-storage capacity and low thermal conductivity, enabling low-rise constructions. The diffusion openness and high moisture-storage capacity of this environmentally-friendly roof underlay panel ensure building physics safety in roofs and walls and promote a healthy indoor climate.
- Guarantees a raintight seal up to 3 mm thanks to a patented tongue-and-groove profile and high insulation value
- Highest hail protection class HW5 (TÜV tested)
- Temporary roof: 3 months of exposure to the elements
Nominal value of thermal conductivity λD
0,042 W/mK
Design value of thermal conductivity λB
0,044 W/mK
Product details
No chance of leakage at the joints of construction elements such as roof windows or chimneys
The Gutex Ultratherm underlay panel scores points with its robust, rainproof edge profile, which allows for quick and safe installation. The innovative tongue-and-groove joint directs rainwater that seeps in from the flush edge to the bevelled panel below. Thanks to this bevel, water remains parallel to the rafters, from the ridge to the eaves, without being deflected sideways – a common problem with traditional profiles, which can lead to unexpected leaks at the joints of building elements such as roof windows or chimneys. In addition, the tongue and groove assembly ensures a windproof seal and effectively protects the insulated construction from cold air. A practical marking on the tongue indicates whether the panels are accurately fitted, thus facilitating quality control.
Raintight sub-roofing by interlocking only
Manufactured with respect for the environment, Ultratherm can be installed raintightly from a roof pitch of 15°, without additional covering or gluing, and does not require nail joints for a "joint- and puncture-protected sub-roof". The environmentally-friendly wood fibre board can be combined in different thicknesses, providing effective over-insulation of the eaves, for example. Thanks to its dimensional accuracy and single-layer, homogeneous raw density profile, Ultratherm minimises thermal bridges and provides additional acoustic insulation.
A comprehensive guarantee
Gutex has lodged a guarantee with the Central Association of German Roofing Tradesmen for Ultratherm, which is secure in terms of building law and application technology, and covers not only the replacement of the material, but also the dismantling and assembly costs and scaffolding costs incurred in the event of a claim.
- Time-saving and safe installation without the need for nail-on sealing strips or additional gluing, thanks to the windtight tongue-and-groove joint and quality marking
- Versatile combination in different thicknesses, ideal for over-insulating eaves
- Additional protection against noise and heat thanks to a homogeneous gross density profile and insulating material instead of an under-roof strip
Ingredients
- Untreated fir and spruce wood
- 4.0% PUR resin
- 0.75% paraffin
Ultratherm wood roof underlay panel: proven rain resistance up to 3 mm joints
Storage and processing
- Store and use Ultratherm in a dry place
Rafter spacing
Maximum centres depending on panel thickness :
- 50/60 mm: max. 110 cm
- 80-160 mm : max. 125 cm
Cutting
- When using standard woodworking machinery, the legal requirements for handling wood dust must be observed.
Installation
- Ultratherm is not a load-bearing element (e.g. for snow loads).
- The sheet cannot be installed in a fixed/static position.
- Cross joints are not permitted.
- Only use undamaged panels.
- Increased humidity on the room side should be avoided.
- The spaces between the rafters are not accessible.
- Lay the panels with the marked side facing outwards, making sure that they fit perfectly and that the joints are watertight, with the groove facing down and the tongue facing up. As a general rule, the panels are laid perpendicular to the rafters.
- Immediately fix the panels with counter-battens; it is not necessary to use strips or nail seals.
- Staggering the joints: stagger each row of panels by at least one rafter centre distance, but by at least 40 cm.
- Cover joints and penetrations raintightly with Gutex adhesive tape and Gutex underlay to ensure a reliable seal.
- Gutex wood fibre insulation boards can be exposed to temperatures of up to 110°C, even for extended periods. Additional measures are required for higher temperatures, e.g. due to solar pipes.
- The minimum distances between combustible building materials and chimneys, etc. must be observed in accordance with the relevant Fireplace Ordinance.
Roof pitch and waterproofing
- < 15° cover with a suitable sheet
- ≥ 15° no gluing of the panel joints is necessary, as long as the roof pitch is not more than 8° below the standard pitch
In the event of discrepancies with the above specifications:
- If the RDN* of the tile and stone roofing is more than 8° lower, measures must be taken to protect the support battens, e.g. support battens made of moisture-resistant materials, water-repellent coverings for the support battens or similar.
Increased requirements result from :
- long rafter lengths > ; 10 m
- concentrated water run-off on partial areas of the roof, e.g. below downpipes or meeting valleys or similar.
- special roofs such as curved dormers, barrel roofs and conical roofs
- areas with heavy snowfall (snow load ≥ 1.5 kN/m²)
- windy regions wind load zone 4 or ridges and peaks or the formation of gorges.
* The regulatory roof pitch depends on the shape of the tile and the type of installation, and is given by the tile manufacturer.
Guidelines for hot air welding
- Only hot air (max. 350°C), no direct buckling.
- Use the appliance for a maximum of 7 to 10 seconds per area; check for discolouration and remove if necessary.
These installation instructions protect Ultratherm from spontaneous combustion, and the installation instructions for the strips must also be observed.
Fixing distances for Ultratherm (thickness ≤ 60 mm, building height ≤ 10 m, indoors)
Important notes
- Fixings must be at least galvanised.
- From an insulation thickness of 80 mm, Gutex Ultratherm must be fixed with approved screws. Various manufacturers offer advice and specific static recommendations for the appropriate screws. Sizing according to fixing manufacturers.
Standard conditions
Detailed training
| Bulk density ρ | ~ 180 kg/m³ |
| Vapour diffusion (μ) | 3 |
| Nominal value of thermal conductivity λD | 0,042 W/mK |
| Design value of thermal conductivity λB | 0,044 W/mK |
| Design value of thermal conductivity λB ACEMI | 0,044 W/mK |
| Compressive stress strength | ≥ 150 kPa |
| Short-term water absorption | ≤ 1 kg/m² |
| Airflow resistance | ≥ 100 kPa s/m² |
| Specific heat capacity | 2100 J/kgK |
| Fire behaviour Euroclass according to DIN EN 13501-1 | E |
| Product standard International | EN 13171 |
| Plate labelling | WF-EN 13171-T5-WS1,0- CS(10/Y)150-TR20-MU3- AFr100 |
| Tensile strength perpendicular to the board surface | ≥ 20 kPa |
| Application according to ZVDH regulations | UDP-A |
