ETICS system with XPS

Solutions & Applications · External Thermal Insulation

It is the only external thermal insulation system that does not function solely on the basis of energy efficiency. Bonding rigid XPS to the infill masonry increases its load-bearing capacity by over 40 per cent — and in a Greek building, this is an argument that stands alongside energy savings, not behind them.

The anti-seismic argument

In buildings with reinforcement, infill masonry is not a load-bearing element — but it does contribute to seismic stress, and often fails first. Out-of-plane failures of masonry are among the most common types of damage following an earthquake, with repair costs disproportionate to the value of the element.

The rigid XPS board, fully bonded and mechanically fixed, acts as continuous external reinforcement for the masonry: it holds the structure together and distributes stresses over a larger surface area. The increase in load-bearing capacity stated by the manufacturer exceeds 40 per cent.

• Very high mechanical strength — protection against impact and punctures at pavement level.
• Virtually zero water absorption — thermal performance is not degraded over time due to moisture.
• Consistent energy performance over a 25-year period, without the decline seen in porous insulation materials in damp environments.
• Exceptional compressive strength — allows for supports and loads to be placed on the insulation.

The system’s layering

System diagram: FIBRAN

Position	Item	Function
1	Interior render	Internal edge finish
2α	External masonry	The element being reinforced
2b	Waterproofing strip	Base protection — the level of contact with the ground
3	Adhesive mortar	Full bonding of the slab to the substrate
4	FIBRANxps ETICS GF	XPS thermal insulation board with a diamond-patterned (‘embossed’) surface
5	Mechanical fastening plug	Wind load assumptions — number and arrangement to be specified by the specifier
6	FIBRANxps CAP	Plug cover cap — elimination of thermal bridges and uniform substrate
7α	Reinforced base layer	Stress and cracking behaviour
7b	Alkali-resistant glass fibre mesh	It is encased in the upper third of the base layer
8α	Primer for adhesion	Uniform absorbency prior to rendering
8b	Final render	Decorative and protective layer

The rhombic surface texture of the board is not for aesthetic purposes: the smooth surface of conventional XPS does not provide sufficient adhesion to mortar. ETICS GF is the range’s dedicated external wall insulation product and bears an ETA — the certificate required for ETICS systems.

That is why XPS across the entire façade is the correct choice only as a certified system comprising ETICS GF boards and its associated materials. A simple, smooth XPS board across the entire façade, used outside the system, is precisely the mistake described in the comparison between EPS and XPS.

Property	Price	Standard
Marking code	XPS – EN 13164 – T3 – CS(10/Y) – DS(70,90) – TR400 – WL(T) – MU50	EN 13164
Thermal conductivity λD (10 °C)	0.033 (≤60 mm) / 0.034 (60–100 mm) / 0.036 (≥120 mm) W/(m·K)	EN 12667
CS compressive strength (10)	200 kPa (20 mm) / 300 kPa (≥30 mm)	EN 826
TR two-sided tensile strength	> 400 kPa	EN 1607
Recommended maximum design load	< 130 kPa	EN 13164
Water absorption WL(T)	1.5 per cent (≤50 mm) / 0.7 per cent (>50 mm) by volume	EN 12087
Water vapour diffusion coefficient μ	50	EN 12086
Dimensional stability DS (70,90)	< 5%	EN 1604
Operating temperature	−50°C to +75°C	—
Reaction to fire	Euroclass E	EN 13501-1
Dimensions & thicknesses	1000×600 mm (1250×600 at 20 mm) · 20–160 mm · L- or I-edge	EN 822 / EN 823

XPS or stone wool: the deciding factor

Project requirement	Field of specialisation
Seismic reinforcement of infill masonry	XPS — increase in load-bearing capacity > 40 per cent
Requirement for A2 classification in the fire protection design	Stone wool
An old building with structural damp	Stone wool — maximum vapour permeability
Pavement level, impact-prone areas	XPS — mechanical puncture resistance
Ground contact zone, basements, perimeter plinth	XPS — zero water absorption
Facade clad with stone or tiles	XPS — bears the load of the cladding
Dark-coloured façade finishes	System utilising heat-reflective technology
None of the above — best value for money	EPS in the main masonry, XPS only at the base

Points where the system fails

1. The base waterproofing layer is omitted: the point of contact with the ground is where moisture rises behind the insulation. XPS can withstand this; mortar and render cannot.
2. Plug caps: without them, every plug head acts as a thermal bridge and appears as a visible mark on the finished surface after the first few winters.
3. Number and arrangement of fixings: these are determined by an analysis of the substrate and a calculation of wind pressure, not by a fixed number per m².
4. Position of glass fibre mesh: it is embedded in the upper third of the base layer. Mesh resting against the insulation does not bear any stresses.
5. Exposure to solar radiation: XPS boards must be protected from UV radiation whilst in storage on site. Prolonged exposure degrades the surface even before they are installed.
6. Getting started guide: the first row is levelled against a base profile. Any error in the first row will affect the entire façade. A gap of 2–3 mm is left between the guides to allow for thermal expansion and contraction; on an uneven substrate, plastic spacers are used.

The base: four functions in one profile

The starter guide is regarded as a consumable and is often omitted or replaced with a makeshift solution. However, it serves four purposes simultaneously, and none of them is optional:

• Levelling: establishes the starting level regardless of any irregularities in the ground. The first course determines the entire façade.
• Drip moulding: an integrated rainwater drainage system that protects the base of the wall — precisely the point where the system fails.
• Rodent and insect barriers: the open lower edge of the insulation is a point of entry. In practice, this is the most common cause of ‘unexplained’ deterioration of thermal insulation on ground floors.
• Mechanical protection of the lower part of the system against damage at pavement level.

Available in widths from 30 to 100 mm — that is, selected on the basis of the thickness of the insulation, not as a general rule.

System Materials

Colours, Dark Shades & Accents

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