Tap to zoom
Tap to zoom
Tap to zoom
Tap to zoom
Tap to zoom
Tap to zoom
Gutex 5in1
Product calculator
Product Overview
Main purpose
External or internal insulation, thermal bridge reduction and windproofing of timber frame and Cross Laminated Timber (CLT) walls, roofs and floors.
Use it on
Timber frame or CLT walls externally behind a vented rainscreen facade. On pitched roofs with a slope greater than 12° covered with Solitex Plus / Solitex Plus Connect (minimum 60mm thickness). On sloping ceilings internally on the underside of rafters. On internal walls (as service cavity insulation). And on solid floor slabs under a screed.
Overview
Gutex 5in1 is a vapour open (breathable), multi-purpose wood fibre insulation board made from recycled wood chips. Its adaptability makes it ideal for 5 different external or internal applications on walls, roofs and floors. Beyond its thermal performance, Gutex 5in1 offers excellent acoustics and low embodied carbon, thanks to its natural materials and manufacturing process. It keeps buildings warm in winter and cool in summer while minimizing thermal bridging.
Gutex 5in1 is a multi-purpose board. The main use cases are:
- Internal Applications: Sloping ceilings on the underside of rafters and timber frame studs (plastered directly or with wood wool board or plasterboard on top).
- External Walls: Solid masonry and timber frame walls.
- Timber Structures: Direct application on Cross Laminated Timber (CLT).
- Pitched Roofs: Above rafters
- Solid Floors: Insulation on top of floor slabs.
Where to use it
This adaptable insulation board offers comprehensive solutions for both internal and external applications. Externally, it can be used as roof sarking, provides full surface insulation on pitched roofs (above rafters, or directly on rafters for 60mm+ thickness with specific pitch and accessory requirements), insulates solid ground floors, and can be applied directly to Cross Laminated Timber (CLT) walls. It also serves as external wall insulation for timber frame systems (behind vented rainscreen or over studs) and solid masonry walls. Internally, it’s perfect for sloping ceilings and timber frame studs, ready for plasterboard installation (fix battens through the board first).
Gutex 5in1 is non-load bearing, so it will not support any structural weight or heavy shelves.
What it does
Gutex 5in1 provides high levels of thermal insulation in the winter and helps prevent summer overheating. The boards also provide an external windtight barrier due to their close-fitting tongue and groove edge profile. Since Gutex 5in1 is mainly used over the external face of timber, thermal bridges that cause heat loss through the timber are eliminated.
Gutex 5in1 can be exposed to the elements for up to 4 weeks during construction to protect the structure underneath from the effects of hail and wind-driven rain before the roof or walls are fully completed.
Why we love it
The primary advantages of Gutex 5in1 stem from its multifaceted performance and significant construction efficiencies. Its five distinct application possibilities streamline logistics and reduce storage overheads, directly impacting project timelines and overall productivity. From a building science perspective, the integrated tongue-and-groove (T&G) jointing system is engineered for exceptional airtightness and water resistance. This is crucial for preventing unwanted air infiltration and moisture ingress, thereby safeguarding structural integrity. Coupled with its vapour-permeable nature, Gutex 5in1 effectively manages interstitial condensation risk, contributing to superior interior air quality. Furthermore, its inherent fire resistance (up to REI 90) and low embodied carbon profile, derived from sustainable wood fibre, solidify its position as a technically superior and environmentally responsible building material.
Features
- Excellent thermal conductivity and mass
- Interlocking tongue and groove edge profile
- Vapour open (breathable) natural insulation
- Environmentally friendly and sustainable
- Multi-purpose with five areas of application
- Wood fibre from renewable forest sources
- REI 90minute fire resistance rating in timber panel systems
- Natureplus certified
- 5 application areas; saves times, reduces storage, simplifies specifications and increases productivity.
- Insulates and stores heat making the building warm in winter whilst protecting from overheating in summer
- Tongue and groove edges make a tight connection between boards, providing wind and water tightness.
- Reduces the risk of interstitial condensation and mould growth, minimising the risk of structural damage.
- Offers up to REI 90 minutes fire resistance rating; charring rather than explosive flash fire.
Questions
Is there any difference between Gutex Thermowall 5in1 and Gutex 5in1?
No. Gutex 5in1 is the same as Gutex Thermowall 5in1
Technical Details
Key Technical Data
Installation Guide
As a sarking board (minimum 60mm thickness on the roof):
The boards should be installed perpendicular to the timber rafter (i.e. horizontally for the length of the boards) and temporarily fixed into place using thermally broken mushroom-headed screws. The boards are then permanently fixed by screwing through the counter battens into the Gutex 5in1 and then into the timber underneath using Heco Topix screws.
Fixing patterns for locations and directions of screws can be obtained by contacting our technical team
If the slope (pitch) is less than 15°, the Gutex 5in1 needs to be covered with a breathable membrane such as Pro Clima Solitex Plus or Pro Clima Solitex Plus Connect. In the case that no membrane is applied over the Gutex 5in1, a number of important details must be addressed. All joints and service penetrations must be primed and securely sealed at the ridge of the roof. Use Pro Clima Tescon RP Primer or Pro Clima Tescon Sprimer to prime the wood fibre, then tape over 150mm Pro Clima Tescon Vana airtight tape.
Underside of the roof with AVCL and boarding underneath
In this scenario, the Gutex 5in1 boards can be temporarily fixed to the underside of the rafter using thermally broken screws (for example, Termofix 6H-NT) - typically 6 screws per board. An AVCL membrane, such as Pro Clima Intello Plus, can be stapled to the underside of the board and then battened over. The finishing board (plasterboard or Cewood wood wool board) can then be fixed to the battens.
Underside of the sloping ceiling, directly lime plastered
In this scenario, it is essential that the board is securely fixed in order to avoid any movement and hence potential cracking of the plaster finish. In order to achieve this, a minimum 60mm thickness of Gutex 5in1 should be used and fixed with thermally broken screws (21 screws per board). If the sloping ceiling pitch is >30 degrees, then the maximum centre spacing of the rafters should be 400mm and if the pitch is <30 degrees, then the maximum centre spacing of the rafters should be 300mm. The safest approach is to install a board (minimum 20mm thickness) to the underside of the rafter and then fix the Gutex 5in1 boards over this, and then directly apply lime plaster.
Timber frame walls with vented rainscreen cladding.
The boards should be installed perpendicular to the timber stud (i.e. horizontally for the length of the boards) and temporarily fixed into place using thermally broken mushroom headed screws. The boards are then permanently fixed by screwing through the counter battens into the Gutex 5in1 and then into the timber underneath using Heco Topix screws.
Fixing patterns for locations and directions of screws can be obtained by contacting our technical team.
With sawn off butt joints at wall-to-wall corners then the surface should be primed Pro Clima Tescon RP Primer or Pro Clima Tescon Sprimer and then the junction taped with Pro Clima Tescon Vana Tape.
Solid masonry Walls
As Gutex 5in1 is a rigid board, the wall should first be levelled with a lime-based plaster such as Diathonite Thermactive .037 (for faster drying and additional insulation) or some other breathable lime-based plaster. After the levelling plaster is fully dry, Gutex’s breathable adhesive mortar should be applied to the back of the boards using an 8mm notched trowel. The adhesive should cover the entire surface of the board with no gaps. The boards can then be tiled into place. Tap the boards firmly onto the wall so every bit of adhesive is in contact with the board.
If you find the adhesive on the back of the board does not fully contact the wall so every bit of adhesive is in contact with the board.
Using a trowel with a wider notch so the thickness of adhesive is slightly greater (e.g. 10-12mm notch instead of 8mm) may be useful if you discover parts of the wall are not perfectly level or smooth.
Please note: if you do use a wider trowel or you apply adhesive to the wall and the board or the wall is not level, you will need more adhesive. The quantity calculator on this website provides quantities based on the assumption that the wall is perfectly level and that an 8mm notched trowel is used to apply the adhesive to the board only.
The Gutex 5in1 system can be finished off with a breathable plaster like Lime Green Solo plaster. Lime Green Solo has been tested and approved by Gutex for use as a breathable base coat and finishing plaster for Gutex 5in1 boards. If used, apply a 5mm coat then cover with Thermoroom reinforcing mesh, then a second 5mm layer.
Use a trowel to gently embed the mesh into the surface of the plaster. Immediately apply a second 5mm coat of Lime Green Solo on top. Use a wide plaster spatula to preliminarily smooth the surface; it doesn’t need to be perfect at this stage. Once the plaster begins to set and is firm enough so that touching it with your finger does not cause an indentation (approximately 2 hours), use a damp sponge to gently smooth out the surface and level out any trowel marks or uneven areas.
The sponge provides a level final finish with a semi-smooth texture. If you would prefer a smoother finish, use a flexible trowel 30 minutes after sponging to polish the surface. The Lime Green Solo should then be painted with a natural breathable paint, such as supplied by Auro.
The boards can be cut to size using a Bahco Profcut Insulation saw.
Solid Floors
In the absence of a damp proof membrane (DPM) under an existing concrete slab, then a new DPM should be installed on top of the slab. The Gutex 5-in-1 boards can then be installed on top of the DPM. After the Gutex 5-in-1 has been installed, then another layer of polythene membrane should be installed over and then the floor finish.