Double laminated floor underlay 3mm

Double laminated floor underlay TERMOFOL TF-PI 5 mm – dedicated for heating foil

TERMOFOL TF-PI 5 mm is a flexible floor underlay developed for underfloor heating systems with heating foil. It is designed for direct use under floating floors, especially under laminated panels and layered floor elements. This application of the product has also been specified in the National Technical Assessment ITB-KOT-2020/1321.

The underlay has a double laminated construction – the upper layer is made of PET foil, while the lower layer is made of metallized PET foil (ALU). It has been designed as a component of the floor system working with TERMOFOL heating foil.

Practical complement to the heating foil system

TF-PI serves as an underlayment layer between the substrate and the floating floor system. Its parameters have been selected considering its use in underfloor heating – the declared thermal resistance is ≤ 0.15 m²K/W. The underlay with a vapor barrier layer also achieves a vapor diffusion resistance of SD ≥ 75 m.

Main features

• dedicated for underfloor heating with heating foil,
• designed for laminated panels and floating floors,
• double laminated construction – PET + metallized PET foil (ALU),
• thickness 5 mm,
• thermal resistance R ≤ 0.15 m²K/W,
• diffusion resistance with vapor barrier layer SD ≥ 75 m,
• short-term absorbency ≤ 0.5%,
• reaction to fire Efl,
• width 100 cm,
• roll length 50 m.

TERMOFOL TF-PI 5 mm is an underlay designed for building a complete floor system with heating foil – it combines the function of an underlayment layer with parameters adapted to electric underfloor heating.

The product is intended for use only in accordance with EN 16354:2012 and the manufacturer's installation instructions. The manufacturer is not responsible for the consequences of improper installation, substrate selection, or changes in the floor structure resulting from use.

Important: the TF-PI 5 mm underlay is not intended for use under vinyl panels.

Application under underfloor heating

TERMOFOL double laminated underlay is intended for use under heating film in electric underfloor heating systems with floating floors. It is used under laminate panels and engineered wood – not intended for vinyl panels.

It serves as a layer between the substrate and the heating film, helping to level and compensate for minor substrate unevenness, while the metallized reflective layer supports directing heat towards the heated floor. The printed grid facilitates planning and installation of the system.