Hardened insulating foil UHP50 (STIROTERMAL SOLO)

Product detailed description

This rigid insulation board is specifically designed for underfloor heating systems in industrial, automotive and production environments. It provides a stable base for pipe laying while ensuring thermal efficiency through its reflective foil. The board includes mechanical features such as interlocking edges and protrusions to secure the pipe in place during installation. It is suitable for use with standard pipe diameters of 14 to 18 mm and allows for pipe spacing options of 50, 100, 150 and 200 mm.

The board is manufactured from hardened polystyrene (PS) with a 1 mm thick black foil layer. Its total height is 23 mm, and the net usable size is 1400 x 800 mm, covering a net area of 1.12 m². Each board is designed to interlock with adjacent boards via a built-in locking mechanism, preventing concrete penetration underneath the insulation. The board’s surface contains octagonal protrusions that hold the pipes securely during installation and ensure even grout coverage around the pipe circumference.

Technical parameters

Net board area	1.12 m²
Net board dimension (real usable dimension)	1400 x 800 mm
Foil colour	black
Foil thickness	1 mm
Foil material	PS
Fire classification DIN 4102	B1
Fire classification EN 13501-1	E
For pipe diameter	14 – 18 mm
Pipe spacing	50, 100, 150, 200 mm
Total sheet height	23 mm
Country of origin	EU
Quantity per package	22.4 m²
Foil overlap	50 mm
Weight	1.3 kg
Code	STIROTERMAL SOLO
Brand	Fragmat

The technical parameters are essential for correct system design and installation. The 1 mm PS foil thickness ensures sufficient rigidity and reflectivity for efficient heat transfer. The board is compatible with pipe diameters between 14 and 18 mm and supports multiple pipe spacing options. The 50 mm overlap between boards ensures continuous insulation and avoids thermal bridging. Fire classifications DIN 4102 B1 and EN 13501-1 E indicate its moderate fire resistance, suitable for non-residential applications.

Installation and connection

The installation process begins by laying the boards directly on a flat, level surface. The interlocking edges ensure seamless alignment and prevent gaps between boards. The octagonal protrusions on the upper surface hold the pipes in place during installation, reducing the risk of displacement. After placing the pipes according to the required spacing (50, 100, 150 or 200 mm), the system is ready for grouting. It is important to verify that the protrusions allow full grout coverage around the pipe to maximise heat transfer efficiency.

Common installation mistakes include incorrect overlap (less than 50 mm) and failure to align the interlocking edges properly. This can lead to uneven heat distribution or reduced system performance. Always check that the board is fully seated and that the protrusions are intact before securing the pipes. Avoid bending the board during transport or installation, as this may compromise its structural integrity.

Compatibility and accessories

This board is compatible with standard underfloor heating systems using pipes with outer diameters between 14 and 18 mm. It is typically used in conjunction with a grouting compound to fill the spaces around the pipes and ensure even heat distribution. For larger pipe networks or higher flow rates, it may be necessary to combine this board with a distribution plate such as the UHPS distribution plate. In dry screed applications, the UHPD (STIROTERMAL DRY) polystyrene board may be used instead.

When ordering, ensure that the quantity of boards matches the required coverage area. Each package contains 22.4 m² or 20 individual boards. Additional materials such as grouting compounds and pipe fixing clips may be required depending on the project specifications and local regulations.

Technical background for designers

The board operates by reflecting heat upwards from the pipes and minimising heat loss into the subfloor. The hardened PS material offers good mechanical stability and resistance to deformation under normal installation conditions. The octagonal protrusions ensure that the pipes are fully encased in grout, improving thermal contact and reducing cold spots. The interlocking edge design prevents lateral movement and ensures a continuous insulation layer beneath the screed or floor covering.

Designers should consider the board’s fire classification when planning the system. The DIN 4102 B1 and EN 13501-1 E classifications indicate that the board is suitable for non-residential or industrial environments where fire resistance is not a primary concern. The board’s thickness and material properties contribute to the overall thermal performance of the underfloor heating system. Proper spacing and overlap are critical for achieving uniform heat distribution and avoiding thermal bridging.

Service and operation

During operation, the board requires no active maintenance. However, periodic visual inspections are recommended to ensure that the board remains intact and that the pipes are securely positioned within the protrusions. Any damage to the board or misalignment of the interlocking edges should be corrected to maintain system efficiency. There are no scheduled service intervals for this product.

Key checkpoints during operation include verifying that the pipes remain in their designated positions and that the grout has fully hardened. If the system is not performing as expected, check for gaps between boards or improper pipe placement. The board itself does not degrade under normal operating conditions and does not require replacement unless damaged.

Frequently asked questions

Is the board compatible with all pipe diameters between 14 and 18 mm?
Yes, the octagonal protrusions accommodate any pipe with an outer diameter between 14 and 18 mm, ensuring secure positioning during installation.

How does the interlocking edge improve installation?
The built-in lock ensures that each board overlaps the adjacent one by 50 mm, preventing concrete or grout from seeping underneath and maintaining a continuous insulation layer.

Can this board be used with dry screed systems?
No, for dry screed applications, the UHPD (STIROTERMAL DRY) board is recommended instead.